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Petitioned Public Health Assessment

Carolina Solite Corporation
EPA ID#: 980557730
Aquadale, Norwood, North Carolina

September 12, 2001

• Summary
  
• Introduction
  
• Background
  
• Demographics
  
• Community Health Concerns
  
• Discussion
  
• Methods
  
• Extent of Contamination
  
• Air
  
• Ambient Air
  
• Particulates in Air
  
• Employee Air Sampling
  
• Drinking Water Wells
  
• ATSDR Child Health Initiative
  
• Health Outcome Data
  
• North Carolina Department of Health Cancer Investigation
  
• Biological Sampling
  
• Public Health Implications
  
• Contaminants of Concern
  
• Arsenic
  
• Cadmium
  
• Chromium
  
• Physical Hazards
  
• Conclusions
  
• Recommendations
  
• Public Health Action Plan
  
• Authors/Site Team
  
• References

Appendices

• Appendix A: Site and Facility Maps
  
• Appendix B: Demographics
  
• Appendix C:Explanation of Methodology and Pathways Table
  
• Appendix D:Air Sampling Results
  
• Appendix E: Residential Well Sampling Results
  
• Appendix F: Biological Sampling Results
  
• Appendix G: Community Health Concerns
  
• Appendix H: Cancer Risk Evaluation
  
• Appendix I: Public Comments
  
  

In August 1998, NC WARN (North Carolina Waste Awareness and Reduction Network) petitioned the Agency for Toxic Substances and Disease Registry (ATSDR) to conduct a public health assessment of the areas surrounding the Carolina Solite facility located in Aquadale, North Carolina. The petition was filed on behalf of area residents. Residents are concerned about adverse health effects they believe are the result of long term exposure to emissions from the Solite facility.

ATSDR reviewed all available environmental and health outcome data and concludes that the data do not suggest a current threat to human health. Data reviewed for this document indicate that environmental media may contain chemical contamination, but below levels that have been associated with adverse health effects. Biological data do not reflect exposures to contamination at levels of health concern.

Based on all available data, ATSDR has made the following observations:

• Air:  Current ambient air contamination and particulate matter concentrations in the community are not a public health hazard. Onsite emissions are not a public health hazard to Solite employees. ATSDR was unable to assess health implications of past exposure because no historical environmental sampling data exists.
  
  
• Groundwater:  Current tests indicate that groundwater in this community is safe for human consumption. Levels of metals and volatile organic compounds detected in groundwater are within acceptable ranges of drinking water quality guidelines. Metals, such as iron, detected in low concentrations are most likely naturally occurring in this geographic zone.
  
  
• Biological:   Biological data do not indicate exposure to high levels of contamination. Inorganic arsenic was not detected in residents tested for heavy metals. Other heavy metals detected were within the range of a healthy unexposed population.
  
  

On August 8, 1998, the North Carolina Waste Awareness and Reduction Network (NC WARN) petitioned the Agency for Toxic Substances and Disease Registry (ATSDR) to conduct a public health assessment on the impact of industrial emissions from the Carolina Solite facility on area residents [1]. ATSDR reviewed and evaluated available data from the North Carolina Department of Health and Human Services (NC DHHS) and the North Carolina Department of Environment and Natural Resources (NC DENR). ATSDR evaluated community concerns and available air, groundwater, and biological data to determine the potential and extent of the exposure of residents to environmental contamination. The purpose of this document is to identify potential human exposures and to recommend appropriate public health follow-up activities.

The Solite facility is located near Aquadale, North Carolina. Aquadale is approximately 45 miles east of Charlotte. The property surrounding the facility is rural farmland and residential. The most populated area is due east approximately five miles in the town of Aquadale. Maps of this area are located in Appendix A.

Solite began operating in Aquadale in 1953, producing lightweight aggregate for the construction industry. The facility is regulated as a boiler and industrial furnace (BIF) under state and federal hazardous waste laws and regulations. The facility produces lightweight aggregate by heating slate and shale mined in an onsite quarry in four large rotary kilns. As the shale and slate are heated, gases are released causing them to expand. The expanded product, referred to as Solite^®, is lightweight, fire resistant, weather resistant, and provides insulating properties [2]. It is used in construction for masonry rocks and concrete. The Solite facility primarily consists of a quarry from which shale and slate are extracted, an inactive quarry, a storage and handling area for the raw material, the rotary kiln process area, and product storage and handling areas [2]. The facility encompasses approximately 125 acres [3].

In the past, Carolina Solite has used a number of fuels to fire its kilns. In Spring of 2000, the facility agreed to use waste oil and coal exclusively in its heating process. From 1983 until 2000, the facility burned Hazardous Waste Derived Fuel (HWDF), waste oil, and coal to fire the furnaces. Carolina Solite received the HWDF via a pipeline and trucks from Giant Resource Recovery, a contiguous permitted liquid waste blending and storage facility [3].

Demographic information was collected in a five block group area surrounding the Solite facility. Current population estimates for this area are available for 1998 at the census block group level only [4]. Block groups contain between 250 and 550 housing units and are often used to distinguish area neighborhoods. This data was collected from census tract 9910 (4), 9910 (5), 9909 (4), 9909 (3) and 9907 (3). Appendix B, Table 1 provides data for these block groups as well as comparison data for Stanly County.

The block groups in this area are predominantly Caucasian; approximately 90% of the 5629 residents are Caucasian. African Americans account for 9.3% of the total population and about 1% are of another race. Less than 1% of residents are of Hispanic origin. Median age varies for these block groups (between 36.1-40.2), but average 38.4 years. This is slightly higher than the county, whose median age is 37.1. Figure 1 and Table 1 in Appendix B illustrate the age distribution in this community. The median number of school years completed is 12.3. Median household income in this area varies greatly, from $30,750 to $39,318, but averages $34,815. This is on average higher than the median household income of the county, which is $31,652. The area appears to be relatively stable in that the median length of residence is 15.5 years, in contrast to the county which has a median length of residence of 13.8 years [4].

There are 2251 housing units in these block groups, and the vast majority are occupied (92.2%). Most people own their homes; 85% of residents living in this area own their homes. Approximately half the homes in this area were built before 1970 (50.4%), and 20.5% were built before 1949. The median housing value in this area is almost equal to that of the county ($65,434 vs. $65,283) [4]. For additional demographic information, see Appendix B.

In the early 1990s, residents expressed their concerns to state authorities about potential environmental contamination and human exposure from site emissions. The concerns included the incidence of different types of cancers, Alzheimer's Disease, asthma, sinus conditions, and neurological illnesses. Specific cancers of concern were: leukemia and brain, kidney, colon, lung, and skin cancers. The North Carolina Department of Health and Human Services (NCDHHS) and the North Carolina Department of Environment and Natural Resources (NC DENR) have investigated contamination, exposure, and compliance issues at the facility and surrounding areas. Sampling has consistently detected metals in ambient air near the facility. Groundwater monitoring in 1991 found elevated metals in monitoring and supply well, surface water, and sediment samples collected near or on Solite property. Of particular concern to state agencies and residents is the level of arsenic that has been detected in residential air. Currently, the United States Environmental Protection Agency (EPA) is analyzing soil and sediment data collected during the Spring of 2000. A discussion of these health concerns can be found in Appendix G.

In preparing evaluations of environmental data, ATSDR uses established methodologies for determining how people may be exposed to potential contamination from surrounding industry, and what effects, if any, may result from exposure to those contaminants. The ways that people may come into contact with chemical contaminants, called 'exposure pathways', are also evaluated. The exposure pathways that ATSDR evaluates include ingestion (eating), inhalation (breathing), and skin contact.

If one or more of the exposure pathways are established, ATSDR then considers whether chemicals have been or still are present at levels that may be harmful to people. ATSDR first does this by screening the concentration of contaminants detected in air, water, or soil against their health-based comparison values. Comparison values (CVs) are often based on animal studies because relevant human data are lacking. CVs are therefore derived using very conservative assumptions and often have large safety factors built into them to be protective of human health. Some CVs may be hundreds or thousands of times lower than exposure levels shown to produce effects in laboratory animals or humans. Thus, ATSDR's CVs are designed to be orders of magnitude lower than levels known to produce adverse health effects. Although chemicals detected at or below CVs are considered safe, any concentration that exceeds a CV would not necessarily be expected to produce adverse health effects. Chemicals detected above CVs require a more detailed evaluation of site-specific exposure conditions. ATSDR emphasizes that regardless of the contamination level, a public health hazard exists only if people come in contact with, or are otherwise exposed to, harmful levels of contaminated air, soil, or water.

If ATSDR has not established a CV for a chemical, then one developed by a different agency is used. If no CV of any kind is available for a chemical, then that chemical is further evaluated. For all site-related contaminants that are detected at levels above CVs, ATSDR reviews relevant scientific literature to determine if site-specific exposures could pose a hazard to public health.

For a complete discussion of these criteria (quality assurance considerations, human exposure pathway analyses, ATSDR's health comparison values, and the methods of selecting contaminants above comparison values), please refer to Appendix C.

This health assessment will review air monitoring data, residential well data, and health outcome data provided by NC DHHS and NC DENR from the Carolina Solite Corporation.

NC DHHS and NC DENR provided ATSDR with residential well data on separate properties sampled in 1991 and 1999, air monitoring data on four sampling sites that were collected throughout 1999, personal monitoring data of employees of the Carolina Solite facility, cancer statistics, and urine sample data for 30 residents living in the area collected during 2000. This analysis is based on the site-specific data provided to ATSDR for review, which are limited in scope by the time period of the data collection and by the assumption that proper quality assurance/quality control standards were followed in analyzing laboratory results. The results of soil and sediment sampling collected by the EPA will be evaluated in a future public health consultation. Through air monitoring, arsenic has been identified by NC DHHS and ATSDR as a contaminant of concern at this site.

ATSDR has identified ways in which area residents may have come in contact with site-related contamination:

1. Previous or current inhalation of contaminated ambient air.
   
   
2. Skin contact with, inhalation and ingestion of contaminated surface soils.
   
   
3. Skin contact with, inhalation and ingestion of contaminated groundwater.
   
   

ATSDR evaluated human exposure to determine whether nearby residents are exposed to contamination migrating from the site. An exposure pathway contains the following five elements: a source of contamination, transport through some kind of environmental medium (air, soil, or water), a point of exposure (a water well, or emissions stack), a route of exposure (breathing, eating, drinking), and an exposed population. In this assessment, ATSDR evaluated chemicals in the air and groundwater that people living in the nearby residences may consume or contact in some manner.

Four ambient air monitoring sites were located and operated in near the Solite property in 1999 by NC DENR, Division of Air Quality. Two additional monitoring sites were located in the area in 2000. However, only 1999 data is analyzed in this health assessment. Four of the six monitors that have been located in the area were operated until the middle or end of 2000. One of these includes a regional background site that is not expected to be impacted by facility emissions. The initial sites and one of the locations added in 2000 were placed in locations believed to be maximum impact areas. These areas were determined by NC DENR using emissions modeling techniques.

The total suspended particulate (TSP) samples collected in 1999 were analyzed for heavy metals and particulate matter. The heavy metals sampled included beryllium, chromium, manganese, cobalt, nickel, arsenic, selenium, cadmium, antimony, and lead. Of these contaminants, arsenic, cadmium, and chromium exceeded ATSDR health-based guidelines (CVs). Chromium and arsenic concentrations exceeded CVs in 168 of the 169 samples collected. Cadmium was also frequently detected; it exceeded CVs in 51 out of 169 samples collected. The results of the 1999 data, as well as a map of sampling locations can be found in Appendix D.

Arsenic and cadmium sources in ambient air have not been specifically identified. Although the facility is possibly contributing to the contamination, farming practices may also increase levels of arsenic and cadmium. The area surrounding this facility is rural and agricultural crops are common, especially cotton. Arsenic is a common ingredient in agricultural chemicals such as insecticides, herbicides, algaecides, and growth stimulants for plants and animals [5]. In 1999, Stanly County harvested 11,500 acres of cotton [6]. Monosodiummethylarsenate (MSMA) is used extensively on cotton fields to control weeds. MSMA is 46% arsenic by weight. Also, disodiummethylarsenate (DSMA) is a common herbicide used in cotton farming, but is usually applied at a higher concentrations than MSMA. State officials report that the manufacturer recommended application of MSMA is 2.1 pounds applied per acre of cotton fields, 46% of which is arsenic [7].

Upon investigation, ATSDR determined that during 1999 the highest concentrations for arsenic could not be clearly associated with harvest and summer planting months when soils are disturbed. In Stanly County, the three largest crops are soybeans, cotton, and corn. These crops are usually planted between April and June, and harvested in late September or later. For example, the bulk of cotton crops are planted by the 10^th of May. The cotton crops receive applications of MSMA and DSMA in late May when the crop is in a "two leaf" stage and plants are very young, and again in late June prior to first bloom [8]. The peaks observed in arsenic levels in 1999 were not observed during the periods of MSMA and DSMA application, but later in July and through August. The cotton planting month of May and harvesting month of October were not found to have notably high peaks to associate with arsenic levels sampled in air monitors.

Cadmium carbonate and cadmium chloride have been used as fungicides on lawns [9]. Chromium is not a common ingredient in agricultural products. Because there are many potential sources of chromium in air, sources besides the Solite facility have not been identified.

Air monitoring technology presently has the capability of monitoring air particles in a range of sizes, measured in micrometers. PM10 refers to particulates that are 10 micrometers in diameter or less, and PM2.5 refers to dust particulates that are 2.5 micrometers in diameter or less. Total suspended particulates (TSP) refers to a particulate concentration of all sizes. The total suspended particulate procedure captures measurable particulates as small as 0.1 micrometers (40 CFR50- Appendix B). EPA has established regulatory guidelines of particulate concentrations that are safe to breathe in ambient air. EPA had specific regulations for TSP of 150 g/m³ (micrograms per cubic meter) for 24-hour averages and 75 g/m³ for annual averages, but decided that more specific guidelines for the size of the particle was necessary. These guidelines are given for both average 24-hour concentrations and for average annual concentrations. In addition, samples were collected for particulate matter equal to and less than 10 micrometers in diameter (PM10). The particulate sampling technique for collected PM10 is also published in the Federal Register (40 CFR50-Appendix J). Currently, EPA has established acceptable 24-hour average concentration averages for PM10 of 150 g/m³ and 50 g/m³ for PM10 annual averages. Acceptable PM2.5 regulations are currently being negotiated by EPA.

In the community around the Solite site, particulate matter was sampled continuously for nine months at two locations, and 24-hour averages were taken every day during that time. TSP levels were recorded for the entire nine month period (January through mid-September) at two sampling sites, and PM10 was collected from mid-May through December 1999 at two sites.

All of the daily TSP and PM10 results were below the previous EPA recommended levels of 150 g/m³ (24-hour average) for three of the four 1999 monitoring locations. One TSP monitoring site was closed down by NC DENR, Division of Air Quality, when it was determined that the sampler was impacted by dust originating from a nearby dirt road. It exceeded EPA recommended levels for 5 days during the monitoring period, most likely because of its susceptibility to dust from passing traffic. The nine month averages of the monitors were within acceptable annual ranges of 75g/m³ for total suspended particulates and 50g/m³ for PM10 [10]. See Appendix D, Table 2 for particulate sampling data.

In July 2000, NC DHHS conducted an industrial hygiene survey at Carolina Solite Corporation to evaluate employee exposure scenarios and contaminant exposure levels. Exposures were measured in each department of plant operation. However, contractors employed for drilling and blasting operations were not tested. In all, 12 employees were tested for contaminant respiration in their working areas [11].

The samples were collected and analyzed for metals using appropriate equipment and testing methods designated by the Occupational Safety and Health Administration (OSHA). A sample of bulk dust was collected from a drill hole in the quarry and a bulk sample of expanded raw material ('clinker') was also analyzed. Data from this investigation is provided in Appendix D, Table 3. Only chromium was detected in the airspace of a single employee. Further discussion is provided in the contaminants of concern section of this document.

Historical permit violations have resulted in spot sampling of different areas of the Solite property. In the early 1990s, elevations of organics, such as acetone, methyl ethyl ketone, napthalene, benzene and benzene derivatives, furans, and phenanthrene were detected in creeks, ponds, and wastewater system leaks where they were illegally being discharged. Metals were also detected in these sampling efforts. They included zinc, aluminum, iron, lithium, arsenic, manganese, magnesium, cadmium, copper, chromium, and barium. Concerns about leaching of contamination into water sources prompted the investigation of potential residential water well contamination. Residential wells were sampled in 1991 and 1999. The 1991 sampling did not indicate chemical contamination of residential wells, but did indicate slight elevations of iron and manganese in several wells. The investigation concluded that the elevations of these metals were most likely naturally occurring and were not a threat to human health.

Thirteen residential drinking water wells were sampled by the North Carolina Department of Environment and Natural Resources, Division of Water Quality in October 1999. Wells were sampled for volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and metals. Barium, copper, iron, lead, and manganese were detected, all at levels below ATSDR comparison values (CVs) and EPA risk based guidelines (RBCs). Iron was the most commonly detected in 10 of 13 wells. All metals detected were below National Primary Drinking Water Regulations for all metals except iron and manganese, neither of which have primary standard levels. Both of these metals slightly exceeded Secondary Drinking Water Regulations, which are non health-based guidelines. These are the same metals detected in 1991 in low concentrations, and are most likely naturally occurring in this geographic zone. Arsenic and cadmium as well as several other metals were below detection limits (BDL); however, the detection limit of the instrument was higher than some of the most conservative health based guidelines for arsenic and cadmium. Even if these two metals has been detected at concentrations equal to the detection limit of the instrument, they are not expected to result in adverse health conditions. Trace amounts of the toluene, styrene, 1,1-dichloroethane, and chloroform were detected at levels less than 0.5 parts per billion (ppb), all below applicable health based guidelines (Appendix E, Table 1). A map of sampling locations can also be found in Appendix E.

Children are at greater risk than adults for certain kinds of exposure to hazardous substances emitted from waste sites and emergency events. They have a greater risk of exposure for several reasons:

• The developing systems of children can sustain damage if toxic exposures occur during certain growth stages.
  
  
• Children play outside more than adults, and therefore have an increased likelihood of coming into contact with chemicals in the environment.
  
  
• Since they are typically shorter than adults, children breathe more dust, soil, and heavy vapors close to the ground.
  
  
• Children are also smaller, resulting in relatively higher doses of chemical exposure per body weight.
  
  

Therefore, ATSDR evaluated the types and quantities of chemicals detected in the air, water, and soil in the community to determine how children might be exposed and whether levels detected in the community could be associated with any reproductive or developmental effects.

While there are children living in this community, they generally do not have access to the Solite site. During site visits, ATSDR staff did not note any points of access for children to the plant property. ATSDR closely reviewed possible exposure situations for children while evaluating this site (for example, air exposure, trespassing, and soil in the community playground). In its evaluation, ATSDR used the Environmental Media Evaluation Guidelines for children (EMEGs), who are considered the most sensitive segment of the population. EMEGs are estimates of daily human exposure to a chemical that is unlikely to produce non-cancer health effects over a specific duration of time. No special chemical hazards to children were identified on the basis of available data. Because no historical air data are available for the surrounding community, no conclusions could be drawn regarding past air exposures. See Appendix D, page 2 for further explanation of comparison values used by ATSDR in this health assessment.

ATSDR reviewed two investigations conducted by the North Carolina Department of Health and Human Services. One study used existing health data and the other collected new information to examine disease in this community. The studies include a statistical investigation of cancer in Stanly county as well as biological sampling of residents in the area.

Area residents are concerned that emissions from the Solite facility may be causing excess cancer in their community. In response to these concerns, NC DHHS investigated cancer statistics for Stanly County to determine whether or not cancer rates in Stanly County are statistically different compared to rates in North Carolina and the United States. No formal report of this comparison was generated to interpret the comparison, and ATSDR analyzed raw data generated by the North Carolina State Center for Health Statistics.

Almost all diseases or health outcomes occur at different rates in different age groups. Most chronic diseases, including most cancers, occur more often among older people while other outcomes, such as many types of injuries, occur more often among younger people. Therefore, the most common health problems in a community will be influenced by the age distribution within the community.

One means of comparing the pattern of health outcomes in communities of different sizes is to calculate an incidence or mortality rate, which is the number of new cases or deaths divided by the size of the population. In chronic diseases and injuries, rates are usually expressed in terms of the number of new cases or deaths per 100,000 people per year. Adjusting rates for age allows for direct comparison between populations with potentially different age distributions. The cancer rates discussed below are age adjusted cancer rates.

In this analysis, cancer incidence rates of residents living in the same county as Carolina Solite (Stanly County) were compared to cancer rates of residents living in North Carolina and the rates of the entire US population. Stanly County and North Carolina cancer incidence rates were derived from the state cancer registry and population estimates from 1990-1995. Population estimates varied, but the average in Stanly County was approximately 53,064 people from 1990-1995. The state also varied, but averaged 6,905,124 people from 1990-1995 [12].

US cancer incidence rates were extrapolated from the Surveillance, Epidemiology, and End Results program (SEER) of the National Cancer Institute. The SEER database tracks cancers in five states (Connecticut, Hawaii, Iowa, New Mexico, Utah) and six metropolitan areas (Atlanta, Detroit, Los Angeles, Seattle/Puget Sound, San Francisco/Oakland, San Jose/ Monterey). With respect to selected demographic and epidemiologic factors, these areas are reasonably representative subsets of the United States population. The disease rates and patterns documented in the SEER database are accepted as fairly accurate representations of the disease incidence rates and patterns of the United States as a whole [13]. Therefore, the 'normal rates' of disease are often based on cancer rates in the SEER areas.

The cancer incidence and mortality data suggest that age-adjusted cancer rates for all cancers are actually lower in Stanly County than in North Carolina or the United States (336.6/100,000 vs. 367/100,000 and 410/100,000, respectively). However, Stanly County rates of cancer of the brain and central nervous system (CNS), bladder, melanoma, kidney, and liver were higher in Stanly county than in the state. However, only brain and CNS cancers in Stanly County exceeded cancer rates in the US population. These rates are difficult to compare because of the vast differences in population size between county and state and SEER rates. For example, the Stanly County rate of brain and CNS cancers is reported at 6.7 cases per 100,000 people. However, there were only approximately 50,000 residents in Stanly County during the study period. In reality, there were just three cases of brain and CNS cancers diagnosed in Stanly County in the six year study period.

Brain and CNS cancers are quite rare and in the instance of rare diseases, the larger the population from which the rate is derived the better the accuracy. The cancer rate derived from the diagnoses of three individuals is very small and therefore more likely to fluctuate, and is therefore less reliable. The rate of brain and CNS cancers diagnosed in the state and those SEER locations representing the US population cancer rates are more reliable because they are derived from a much larger population.

*estimated

¹It is common to standardize rates by reporting them as a number per 100,000 people. In actuality, Stanly County has about half that many residents, and the actual number of cancer cases reported was 3 from 1990-1995.

² These confidence intervals include 1, and are therefore not considered statistically significant.

Although the rate of brain and CNS cancers appear to be elevated in Stanly County above state and national rates, care should be taken in interpreting the meaning of these results. A further analysis of the rates was necessary to determine whether or not the rate observed in Stanly County are significantly higher than those of the state and U.S. (SEER) population. To test the difference between the numbers for statistical significance a Standardized Incidence Ratio (SIR) was calculated and then tested for significance. The SIR is calculated with a statistical formula; namely, the number of observed cases in Stanly County divided by the number of expected cases that are diagnosed in the comparison population (state or SEER population). An SIR of 1 means there is no difference between the rates of the two populations. The SIR for this analysis was 1.18 between Stanly County and the state rate and 1.098 between Stanly County and the U.S. (SEER) rate, suggesting that the rate for Stanly County is slightly higher than that of the state (18%) and slightly higher than the US population (9.8%). However, another test is necessary to determine whether or not the difference between the two numbers is statistically significant - i.e., that the numbers are different not by chance, but by some other factor.

The test for significance commonly used in statistics is called a test of confidence. This test is to determine whether the observed number of cases is truly elevated or possibly due to other factors such as a small population size, years observed, inaccurate data, and lifestyle or other risk factors that may influence the results. Although the level of confidence is determined by the investigator, a 95% confidence level is generally accepted as the most common confidence test. This means that the likelihood that the rates are different by chance alone (and that the SIR is greater than 1 by chance alone) is 5% or less. If the calculated confidence interval includes 1, then the SIR is not considered to be statistically significant; it is possible that the increase in the number of cancer cases observed in the population may be due to some other factor.

In this case, calculating the 95% confidence interval revealed that the difference between the state and national incidence rates and the Stanly County brain and CNS cancer incidence rate is not significant. The standard mortality ratio includes 1, and suggests that other factors are contributing to the brain cancers diagnosed, which may include sample size or the number of cases diagnosed. The population of Stanly County is small and the number of brain cancers (3) is also very small. Calculating reliable rates with such a small population size and such a rare cancer is very difficult.

The causes of most brain cancers in humans are unknown. The only environmental exposure for which there is strong evidence for a causal link to brain cancer in adult humans is ionizing radiation [14]. Though rare in children (incidence is approximately 25 per 1,000,000), brain tumors are the most common solid tumors in children. However, these tend to be associated with inherited conditions such as neurofibromatosis, tuberous schlerosis, and von Hippel-Landau disease [15]. Most cancers of the brain are secondary; meaning they have metastasized, or spread from another part of the body. A very small percentage of brain cancers actually originate in the brain. However, the data provided to ATSDR did not differentiate between primary and secondary brain cancers in Stanly County. The American Brain Tumor Association has stated that the incidence rate for primary malignant brain tumors in the United States is 6.6 people per 100,000, which is very similar to the Stanly County rate of 6.7 [16]. None of the contaminants detected in excess of ATSDR's CVs at this site are associated with brain cancer in humans, nor does the magnitude of the exposures and effects at this site suggest any such association.

In summary, more analysis is necessary in determining historical cancer trends in this county, and whether these trends are higher than the expected rates of cancer for Stanly County residents. More importantly, it is difficult to determine whether or not Carolina Solite is contributing to the cancer rates in the county. There are no cancer studies focusing specifically on the residential area surrounding the Solite facility. Furthermore, current environmental data do not support the association between environmental emissions and cancer in residents in this community.

The North Carolina Department of Health and Human Services conducted on-the-spot urine testing for heavy metals in April of 2000. Thirty residents living in the area around the Solite facility were asked to participate in the analysis. Participants included 18 females and 12 males. Ages ranged from 14 to 75 years. Smoking history was reported. Urine was screened for arsenic, mercury, lead, and cadmium. Although a 24-hour urine collection is considered an optimal sample due to fluctuations in excretion rates, most exposure studies, like this one, have used a first morning void or random, on-the-spot sample due to ease of collection [17]. Results were standardized by adjusting detected metals by the creatinine urine concentration.

Data from this analysis indicate that, while there were individuals with detectable concentrations of heavy metals in urine, none of the levels detected were above average ranges for a healthy, unexposed population. Of primary concern was arsenic levels in urine as a measure of exposure because of elevated arsenic in ambient air. In this investigation, arsenic was speciated, or measured in its organic and inorganic form. Speciated urinary arsenic is preferable to total urinary arsenic because the speciated forms can distinguish between exposure to toxic inorganic arsenic and its metabolites and non-toxic organic arsenic [17].

Inorganic arsenic was not detected in the 30 urine samples of residents. Organic arsenic was detected in 5 individuals. Detectable levels of organic arsenic is most likely attributable to diet. Three of the five individuals who had detectable levels of arsenic had eaten seafood within 72 hours of giving a sample [18]. Fish, shellfish, and other seafood are major sources of non-toxic organic arsenic [17]. While residential air has detectable levels of arsenic, urine analysis does not indicate elevated exposure (i.e., outside normal ranges) to inorganic arsenic. See Appendix F for biological sampling results.

'Biomarker' is a term used to describe how testing body fluids or tissues can give researchers clues about whether individuals are exposed to chemicals in their environment. A definition of biomarker is "a measurement made on body tissue, body fluid or excretion to give a quantitative indication of exposure to a chemical and which may give an estimate of the risks consequent on the exposure." Some biomarkers are more reliable than others for detecting the presence of specific chemicals and the sampling time relative to exposure duration can be critical. For example, arsenic is excreted mainly via the kidneys, with a half-life of about ten hours. Most of an ingested dose of arsenic will be cleared from the body in about 3 days [19]. Thus, urinary arsenic measurements will not reflect exposures older than that. Urine analysis is also a reliable test for measuring mercury and cadmium in the body [9,21]. However, measuring urinary lead levels is of questionable value as biomarkers of exposure because of the relatively low and fluctuating levels that are excreted in the urine. Blood lead levels are the preferred biomarkers for measuring lead exposure [22].

Arsenic was identified by NC DHHS and NC DENR as a contaminant of concern because of its elevation in community ambient air. Inhalation exposure to inorganic arsenic (primarily arsenic trioxide dust in air at copper smelters) is, in multiple studies, associated with increased risks of lung cancer in occupational settings. However, scientific literature does not support associations between lung cancer and exposure to airborne arsenic in residential settings [5]. Although serious health conditions can result from acute or long term exposure to inorganic arsenic, ATSDR does not expect adverse health conditions to result from the levels at which arsenic was detected in this community.

Arsenic is used as an animal feed additive [23]. Inorganic arsenic, in very small amounts, has been shown to be an essential nutrient in several species, e.g., chickens, goats, and rats, and although unproven, it is possible that a nutritional requirement for arsenic (estimated at between 12 and 50 ug/day) exists for humans as well [24]. Additionally, our bodies have the ability to change inorganic arsenic into organic arsenic. Negative health effects would be possible if this ability was overwhelmed. Inorganic arsenic is detoxified in the body by a biological process called "methylation". When the methylation capacity of the organism is saturated, the body begins to experience the toxic effects of the arsenic. In healthy humans, this methylation capacity prevents blood arsenic levels from rising at all until oral exposures reach at least 200 g daily. As a result, thresholds in excess of 200-250 g As/day exists for virtually all of the chronic adverse effects of arsenic (including cancer) in humans [24].

Organic arsenic, which is normally present at high levels in seafood, is relatively harmless because it is rapidly excreted. No studies exist that suggest associations between organic arsenic and adverse human health effects [5].

ATSDR's analysis suggests that concentrations of arsenic in the ambient air near the Solite facility is not a threat to human health. Mean levels of arsenic in ambient air in the United States usually range from 1 to 3 ng/m³ (nanograms per cubic meter) in remote areas and from 20 to 30 ng/m³ in urban or industrial areas. Inhalation of arsenic from ambient air is usually a minor exposure route for the general population. For example, the dose to a person who breathes 20m³ a day of air containing 20-30 ng/m³ would be about 0.4-0.6 g/day (micrograms per day) [5]. The highest level of arsenic detected in the air monitoring effort around this site was 24.7 ng/m³, but the vast majority of detects were well below that level. Arsenic was below detection limits in the breathing space of all twelve employees sampled in the industrial hygiene survey. The analytical detection level of worker exposure study (0.5g/m³) is 20 times lower than the safe occupational limit of 10g/m³ (.01 mg/m³), which is the appropriate benchmark for monitoring occupational exposures.

Arsenic was not detected in any of the 13 residential water wells sampled. In addition, urine analysis results did not reflect exposure of residents to inorganic arsenic. Instead the organic arsenic detected by urinalysis was most likely related to diet and recent exposure to seafood. Arsenic was not detected in groundwater, inorganic arsenic was not detected in urine of residents, and detected levels of arsenic in air are not expected to result in adverse health effects.

Cadmium was present in levels above environmental guidelines in ambient air approximately one-third of the time in 1999. Concentrations ranged from 0.61 to 6.3 ng/m³ (nanograms per cubic meter of air). Air cadmium levels in U.S. cities range from 1 to 40 ng/m³ [9]. The biggest sources of cadmium exposure are from food and cigarette smoke. Cadmium is found in small amounts in fruits and vegetables and in larger amounts in leafy vegetables and potatoes, shellfish, and meats [9, 19]. Smokers may inhale 1,000-3,000 ng/m³ of cadmium per day from each pack of cigarettes they smoke [9]. Although severe health effects can result from exposure to cadmium, no adverse health effects are expected to result from exposure to concentrations detected in the environmental media sampled.

While frequently above ATSDR CVs, levels of cadmium observed in the ambient air in this community do not currently pose a threat to human health. The Occupational Safety and Health Administration (OSHA) has determined that workers exposed chronically to cadmium dust or fumes in a typical workweek are safe breathing up to .005 mg/m³ ( 5 ug/m³ or 5,000 ng/m³). That safety level is approximately 800 times the highest level detected in the residential area surrounding the Solite facility. Additionally, cadmium was not observed in personal sampling of Solite employees above analytical detection limits in the state industrial hygiene study. OSHA limits for workers indicate that even at ten times the level of detection in this analysis (which all levels detected were below), the breathing conditions would be safe.

Cadmium was not detected in residential wells and is not a public health hazard at this time. Although cadmium was detected in the urine of ten of the thirty individuals sampled in the urine analysis when adjusted for creatinine levels, it was below the normal range of 5 g/L in all of tested individuals. Levels of cadmium detected in air, water, and urine do not pose a threat to human health at this time.

Chromium also exceeded ATSDR CVs in all but one air sampling effort of 1999. Chromium levels reported were not speciated, and reported levels were for total chromium. Chromium occurs naturally in the environment and has several forms. Chromium III is found in vitamins, dietary supplements, food, water, and air and is an essential nutrient for human survival. Chromium VI and chromium 0 are generally produced in industry. Chronic occupational exposure to high levels of chromium VI in air is associated with an increased incidence of lung cancer. Oral exposure to chromium VI is much less likely to pose a health threat as it is quickly and efficiently converted to the essential nutrient chromium III by the acids in beverages and bodily fluids [25].

Breathing high levels of toxic forms of chromium can result in adverse health effects [19,  25]. These results have generally been documented in factory workers who worked with chromium VI for extended periods of time. Long-term exposure to high levels of chromium VI has been associated with lung cancer. There is no evidence of these outcomes outside occupational settings. Breathing in small amounts of chromium VI does not cause health effects in most people. Levels of chromium detected in ambient air surrounding this facility are well below ATSDR comparison values, and are not expected to result in adverse health effects. These levels, which ranged from 0.18 to 5.5 nanograms (ng) per cubic meter (m³), were all well below ATSDR's chronic Environmental Media Evaluation Guides (EMEGs)/Minimum Risk Level (MRL) of 100 ng/m³ for chromium VI. Chromium was detected at 0.0003 mg/m³ in the air monitor of one of the twelve employees tested by the industrial hygiene survey. This level is below the National Institute of Occupational Safety and Health (NIOSH), OSHA, and American Conference of Governmental Industrial Hygienists (ACGIH) occupational limits of 0.5 mg/m³. Exposure to low levels of chromium measured here are unlikely to result in adverse health effects. During the 1999 sampling, chromium was not detected in the 13 residential water wells. Therefore, ATSDR considers that chromium in air and groundwater does not pose a hazard to public health in this community at the present time.

Access to Carolina Solite Corporation is restricted by fences. ATSDR has not received any information suggesting that children have access or have had access to the property in the past. Trucks regularly enter and exit the property and may pose traffic hazards to playing children and residents. Trucks are hosed off at the property line to prevent off-site contamination from dust and soils that may accumulate on truck bodies and tires while on facility property.

Available environmental data do not indicate the existence of a health hazard at this time for area residents of the Carolina Solite facility. Early in 2000, the facility agreed to discontinue the use of hazardous waste derived fuel to fire kilns, and now burns recycled oil exclusively. Ambient air sampling is needed to determine the impact of this change. Several air monitors have been added to existing stations to facilitate a more complete characterization of air contamination.

Based on data provided for this health assessment, ATSDR concludes the following:

• Air: In ambient air total suspended particulate samples, arsenic, cadmium, and chromium levels are not expected to result in any adverse health effects for area residents. In a study of Solite worker breathing conditions utilizing personal sampling filters, no contaminants were detected at levels of health concern.
  
  
• Residential Water Wells: While there is historical evidence of surface and groundwater contamination of water on Carolina Solite property, current conditions do not indicate contamination of residential water wells sampled in 1999.
  
  
• Biological sampling: None of the 30 individuals tested had urine levels of metals above normal ranges for a healthy, unexposed population. Although residents are exposed to elevated arsenic levels in ambient air, it does not appear that residents are exposed at levels high enough to constitute a health risk or to lead to bioaccumulation of organic or inorganic arsenic in the body.
  
  
• Data regarding rates of brain cancer and cancer of the central nervous system in Stanly County are inconclusive. Current environmental data do not support an association between the Solite facility and county cancer rates.
  
  

1. Air: Analyze ambient air total suspended particulates concentrations for all monitors operated through December 2000 to establish patterns in contaminant peaks, and to more fully characterize ambient air in the community.
   
   
2. Well Water: If contaminants sampled by the EPA are elevated in the sediment of streams and rivers in the area, NC DHHS and NC DENR should develop a public health action plan to monitor residential wells to ensure no leaching is occurring from the facility into groundwater.
   
   
3. Soil and Sediment: Analyze soil to fully characterize contamination on and off-site. Obtain contaminant background levels in soil and sediment from the United States Geologic Survey and the local agricultural extension service for a comparative analysis with EPA data results.
   
   

• The North Carolina Department of Environment and Natural Resources (NC DENR), Division of Air Quality has located six air sampling monitors on the perimeter of the Solite property and a background monitor approximately 6 miles from the Solite property.
  
  
• NC DENR conducted spot soil and groundwater sampling of various areas of the Carolina Solite facility in the early 1990s, and groundwater sampling of residential wells in 1999.
  
  
• EPA has taken soil and sediment samples on residential properties and rivers and streams in the vicinity of the Solite plant.
  
  
• NC DENR, Division of Air Quality monitored total suspended particulates and metals in air through December of 2000.
  
  
• EPA analyzed soil samples taken in the Spring of 2000, and submitted results to NC DENR, NC DHHS, and ATSDR.
  
  

• ATSDR is currently analyzing soil and sediment data collected by EPA in Spring of 2000.
  
  
• ATSDR is currently analyzing ambient air and total suspended particulate data collected by NC DENR from January through December 2000.
  
  
• ATSDR is currently investigating background levels of contaminants of concern with the USGS and the North Carolina Department of Agricultural.
  
  

• ATSDR will address any comments received about this public health assessment by residents, state officials, and other stakeholders.
  
  
• ATSDR will produce a public health assessment for soil, sediment, and air data.
  
  
• ATSDR will continue to give technical support, as needed, to NC DENR and NC DHHS.
  
  

Site Team/Authors

Prepared by:

Michelle A. Colledge, M.P.H.
Environmental Health Scientist
Petitions Response Section
Exposure Investigation and Consultation Branch
Division of Health Assessment and Consultation

Frank Schnell, Ph.D.
Toxicologist
Petitions Response Section
Exposure Investigation and Consultation Branch
Division of Health Assessment and Consultation

Reviewed by:

Benjamin Moore
Regional Representative
Office of Regional Operations
ATSDR Region 4

Donald Joe, P.E.
Section Chief
Petitions Response Section
Exposure Investigation and Consultation Branch
Division of Health Assessment and Consultation

John E. Abraham, Ph.D., M.P.H.
Branch Chief
Exposure Investigation and Consultation Branch
Division of Health Assessment and Consultation

15.  Casciato and Lowitz. Manual of Clinical Oncology, third ed. New York: Brown and Company, pp 258, 315; 1995.

16.  A Primer of Brain Tumors, seventh ed. The American Brain Tumor Association. Revised Nov. 2000.

17.  Imtiaz R. Exposure Investigation Protocol, Vasquez Boulevard and I-70 Site. Agency for Toxic Substances and Disease Registry. U.S. Department of Health and Human Services. Atlanta. September 2000.

18.  Residential Urine Analysis-Solite Vicinity. North Carolina Department of Health and Human Services, Division of Public Health. August 4, 2000.

19.  Goyer RA. Toxic Effects of Metals. Casserett and Doull's Toxicology, fourth ed. New York: Pergamon Press, 1991. Chapter 19, p. 630.

20.   Agency for Toxic Substances and Disease Registry. Toxicological profile for mercury. Department of Health and Human Services. August 1997. Update.

21.  Gebel TW et al. Human biomonitoring of arsenic and antimony in a case of an elevated geogenic exposure. Environ Health Perspect 106:33-39, 1998.

22.   Agency for Toxic Substances and Disease Registry. Toxicological profile for lead. Department of Health and Human Services. 1998. Update.

23.   Kotsonis et al. Food Toxicology. Casarett and Doull's Toxicology. fifth ed. New York:McGraw-Hill, 1996.

24.   Marcus and Rispin. Threshold carcinogenicity using arsenic as an example. Advances in Modern Environmental Toxicology: Risk Assessment and Risk Management of Industrial and Environmental Chemicals. Princeton Scientific Publishing Company, Princeton. pp133-57; 1988.

25.   Agency for Toxic Substances and Disease Registry. Chromium, Toxicological profile for chromium. U.S. Department of Health and Human Services. August 1998.

Appendices

Table 1.   Block Group and County Age Group Data, 1998 Projection*

*Data for this table were generated by the Compass program, with PRIZM applications

¹Where n=5,607 persons

Quality Assurance

In preparing this report, ATSDR relied on the information provided in the referenced documents and contact with community members and representatives, North Carolina Department of Health, and Human Services and the North Carolina Department of Environment and Natural Resources. ATSDR assumes that adequate quality assurance measures were taken during chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn in this document are dependent upon the availability and reliability of the data.

Comparison Values

ATSDR comparison values are media-specific concentrations that are considered to be safe under default conditions of exposure. They are used as screening values in the preliminary identification of site-specific "contaminants of concern". The latter term should not be misinterpreted as an implication of "hazard". As ATSDR uses the phrase, a "contaminant of concern" is a chemical substance detected at the site in question and selected by the health assessor for further evaluation of potential health effects. Generally, a chemical is selected as a "contaminant of concern" because its maximum concentration in air, water, or soil at the site exceeds one of ATSDR's comparison values.

However, it must be emphasized that comparison values are not thresholds of toxicity. Although concentrations at, or below, the relevant comparison value may reasonably be considered safe, it does not automatically follow that any environmental concentration that exceeds a comparison value would be expected to produce adverse health effects. The principle purpose behind protective health-based standards and guidelines is to enable health professionals to recognize and resolve potential public health hazards before they become actual public health consequences. For that reason, ATSDR's comparison values are typically designed to be 1 to 3 orders of magnitude (or 10 to 1,000 times) lower than the corresponding no-effect levels (or lowest-effect levels) on which they are based. The probability that such effects will actually occur does not depends on environmental concentrations alone, but on a unique combination of site-specific conditions and individual lifestyle and genetic factors that affect the route, magnitude, and duration of actual exposure.

Listed and described below are the various comparison values that ATSDR uses to select chemicals for further evaluation, as well as other non-ATSDR values that are sometimes used to put environmental concentrations into a meaningful frame of reference.

Cancer Risk Evaluation Guides (CREGs) are estimated contaminant concentrations expected to cause no more than one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factors, or cancer potency factors, using default values for exposure rates. However, neither CREGs nor cancer slope factors can be used to make realistic predictions of cancer risk. The true risk is always unknown and may be as low as zero.

Minimal Risk Levels (MRL) are estimates of daily human exposure to a chemical (doses expressed in mg/kg/day) that are unlikely to be associated with any appreciable risk of deleterious noncancer effects over a specified duration of exposure. MRLs are calculated using data from human and animal studies and are reported for acute ( 14 days), intermediate (15-364 days), and chronic ( 365 days) exposures. MRLs are published in ATSDR Toxicological Profiles for specific chemicals.

Environmental Media Evaluation Guides (EMEGs) are concentrations that are calculated from ATSDR minimal risk levels by factoring in default body weights and ingestion rates.

Intermediate Environmental Media Evaluation Guides (IEMEG) are calculated from ATSDR minimal risk levels; they factor in body weight and ingestion rates for intermediate exposures (those occurring for more than 14 days and less than 1 year).

Reference Dose Media Evaluation Guide (RMEG) is the concentration of a contaminant in air, water or soil that corresponds to EPA's RFD for that contaminant when default values for body weight and intake rates are taken into account.

Reference Dose (RFD) is an estimate of the daily exposure to a contaminant unlikely to cause noncarcinogenic adverse health effects. Like ATSDR's MRL, EPA's RFD is a dose expressed in mg/kg/day.

Reference Concentrations (RfC) is a concentration of a substance in air that EPA considers unlikely to cause noncancer adverse health effects over a lifetime of chronic exposure.

Risk-Based Concentrations (RBC) are media-specific concentrations derived by Region III of the Environmental Protection Agency from RfD's, RfC's, or EPA's cancer slope factors. They represent concentrations of a contaminant in tap water, ambient air, fish, or soil (industrial or residential) that are considered unlikely to cause adverse health effects over a lifetime of chronic exposure. RBCs are based either on cancer ("c") or noncancer ("n") effects.

Maximum Contaminant Levels (MCLs) represent contaminant concentrations in drinking water that EPA deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day. Methodology of Evaluating Chemicals of Concern

The Agency for Toxic Substances and Disease Registry (ATSDR) has determined levels of chemicals that can reasonably (and conservatively) be regarded as harmless, based on the scientific data the agency has collected in its toxicological profiles. The resulting comparison values and health guidelines, which include ample safety factors (also known as an uncertainty factor) to ensure protection of sensitive populations, are used to screen contaminant concentrations at a site and to select substances (referred to as "chemicals of concern") that warrant closer scrutiny. A "chemical of concern" is defined by ATSDR as any chemical that is detected in air, water, or soil at concentrations exceeding one or more of ATSDR's comparison values. (Refer to Appendix C for a more complete description of ATSDR's comparison values, health guidelines, and other values ATSDR uses to screen site contaminants.)

It is important to understand that comparison values are not thresholds of toxicity. Although concentrations at, or below, the relevant comparison value may reasonably be considered safe, it does not necessarily follow that any concentration that exceeds a comparison value would be expected to produce adverse health effects. Indeed, the principle purpose behind protective health-based standards and guidelines is to enable health professionals to recognize and resolve potential public health problems before that potential is realized. For that reason, ATSDR's comparison values are typically designed to be 1 to 3 orders of magnitude lower than the corresponding no-effect levels (or lowest-effect levels) on which they are based.

When screening individual contaminants, ATSDR staff compare the highest single concentration of a contaminant detected at the site with the lowest comparison value available for the most sensitive of the potentially exposed individuals (usually children or pica children). Typically the cancer risk evaluation guide (CREG) or chronic environmental media evaluation guide (EMEG) is used. This "worst-case" approach introduces a high degree of conservatism into the analysis and often results in the selection of many contaminants as "chemicals of concern" that will not, upon closer scrutiny, be judged to pose any hazard to human health. In the interest of public health, it is prudent to use a screen that identifies many "harmless" contaminants, as opposed to one that may overlook even a single potential hazard to public health. The reader should keep in mind the conservativeness of this approach when interpreting ATSDR's analysis of the potential health implications of site-specific exposures.

As ATSDR's most conservative comparison value, the CREG, requires special mention. ATSDR's CREG is a media-specific contaminant concentration derived from the chronic (essentially, lifetime) dose of that substance which, according to an Environmental Protection Agency (EPA) estimate, corresponds to a 1-in-1,000,000 cancer risk level. Note, this does not mean that exposures equivalent to the CREG are expected to cause 1 excess cancer case in 1,000,000 (1x10^-6) persons exposed over a lifetime. Nor does it mean that every person in a population of one million has a 1-in-1,000,000 risk of developing cancer from the specified exposure. Although commonly interpreted in this way, EPA estimates of cancer "risk" are estimates of population risk only and cannot be applied meaningfully to any individual. EPA explicitly stated in it's 1986 Cancer Risk Assessment Guidelines that "The true risks are unknown and may be as low as zero" (EPA, 1986).

Reference:

EPA, 1986. Environmental Protection Agency. Guidelines for Carcinogenic Risk Assessment. Fed. Reg., 51: 33997-33998, September 24, 1986.

ATSDR Methodology

Methods of Evaluation of Potential Public Health Implications

Based on available scientific data, much of which ATSDR has collected in its toxicological profiles, ATSDR has determined concentrations of hazardous substances that can reasonably (and conservatively) be regarded as harmless. The resulting comparison values generally include ample safety factors to ensure protection of sensitive populations. They are used to screen contaminant concentrations at a site, and to select "contaminants of concern" that warrant closer scrutiny by agency health assessors and toxicologists. A "contaminant of concern" is defined as a substance that is detected in air, water, or soil at concentrations that exceed one or more of ATSDR's comparison values and warrants further evaluation.

The derivation of a comparison value uses conservative exposure assumptions, resulting in values that are much lower than exposure concentrations observed to cause adverse health effects. This ensures that the comparison values are protective of public health in essentially all exposure situations. Therefore, if the concentration of a substance in an exposure medium is less than the comparison value, the exposure is not of health concern and no further analysis of the exposure medium pathway is required.

Comparison values are conservative values, and it is important to note that concentrations of substances that are higher than the comparison values will not necessarily lead to adverse health effects. Exposure to levels of substances above their comparison values may or may not lead to adverse health effects. ATSDR's comparison values do not indicate thresholds of toxicity, and they are not used to predict the occurrence of adverse health effects.

A level of concentration that is equal to or below a relevant comparison value is considered safe. However, the fact that a concentration exceeds a comparison value does not mean that the concentration is expected to produce adverse health effects. ATSDR uses highly conservative, health-based standards and guidelines to assist health professionals in recognizing and resolving potential public health problems.

*ng/m³=nanograms per cubic meter

g/m³=micrograms per cubic meter

¹g/m³= micrograms per cubic meter

²Samples are most likely not representative of true ambient conditions because this monitor was located adjacent to a dirt road.

Table 3. Personal air monitor sampling results for Carolina Solite employees

¹g/m³= microgram per cubic meter

²The comparison values used here are NIOSH Recommended Exposure Levels (RELs), OSHA Permissible Exposure Levels (PELs), and ACGIH Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs), where applicable.

³BDL= below the detection limit of the analytical method

Table 1. 1999 Residential well investigation

¹Please note: trace amounts of the following contaminants were found at levels less than .5 ppb: toluene, styrene, 1,1-dichloroethane, and chloroform. These contaminants detected at these levels or lower are well below ATSDR and EPA health-based guidelines.

²BDL= below detection limits; or that the level detected was below the registering capability of the measuring instrument

³NPDWR (National Primary Drinking Water Standards)- legally enforceable standards that apply to public water systems. Primary standards protect drinking water quality by limiting the levels of specific contaminants that can adversely affect public health and are known or anticipated to occur in public water systems.

⁴ NSDWR (National Secondary Drinking Water Standards)- non-enforceable guidelines regulating contaminant that may cause cosmetic effects (like tooth discoloration) or aesthetic effects (taste, odor) in drinking water. EPA recommends secondary standards but does not require systems to comply. Some states adopt then as enforceable standards.

¹ Measurements are as follows: g/L= grams per liter; g/L= micrograms per liter; g/g= micrograms per gram

²The excretion mechanism of chemicals and metals can be altered when the urine specimen is very concentrated (creatinine>3.00 g/L) or dilute (creatinine<0.50 g/L). In such cases, urinary measurements are not reliable.

³Total arsenic= Inorganic+Organic

⁴ Normal ranges for total cadmium are based on a 24-hour sampling, not on spot urine sampling as conducted in this study.

Health Implications

ATSDR investigated the potential association between contaminants exceeding cancer and non-cancer health guidelines and symptoms and diseases reported by residents. Residents reported cancer as well as a number of other non-cancer adverse health symptoms and conditions. These non-cancer symptoms include: Alzheimer's Disease, asthma, sinus conditions, and neurological illnesses (unspecified). This section addresses these health concerns and whether contaminants of concern could cause or exacerbate adverse health conditions.

Alzheimer's Disease

Alzheimer's disease is a degenerative disease of the brain in which nerve cells are attacked impairing brain function. Over four million people in the United States are living with Alzheimer's disease, which is the most common form of dementia. Experts predict that as baby boomers age, Alzheimer's may affect as many as 14 million people nationwide. Alzheimer's is widespread, affecting 10% or more of those over age 65 and nearly half of those over age 85. Slightly more women than men have Alzheimer's disease. While Alzheimer's disease usually affects those over age 65, a rare and aggressive form of Alzheimer's can happen in some people in their 40s and 50s. Alzheimer's has become progressively more common as the United States population ages, and is very common in the elderly. Besides the elderly, people who have a family history of the disease, those with Down's syndrome or relatives with Down's syndrome, women, and Hispanics and African Americans have an increased risk of Alzheimer's Disease. There is also evidence that people with chronic high blood pressure are more likely to develop Alzheimer's. Some studies suggest environmental factors in developing the disease. Increasing numbers of studies report that estrogen therapy (hormone replacement therapy), nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen (advil, motrin), and naprosyn, and low fat diets can lower a person's risk of developing Alzheimer's.

Residents reported Alzheimer's as a disease they are concerned may be related to emissions from the Solite facility. Alzheimer's disease has a number of risk factors. Proposed, but not well-established environmental and other risk factors include: virus and bacterial infection, exposure to metals, exposure to very high levels of electromagnetic fields, head injury, and childhood malnutrition and vitamin deficiencies.

In this community, the most likely risk factor associated with the Carolina Solite facility is exposure to metals. However, associations between exposure to metals and Alzheimer's are inconclusive. In spite of some early concern that aluminum may have some role in Alzheimer's, studies have found no relationship between the development of Alzheimer's and exposure to aluminum in cooking, occupational work, or drinking water. In addition, ATSDR could not locate any studies in scientific literature that suggested any association between Alzheimer's disease and exposure to any metals besides aluminum, including arsenic, cadmium, or chromium. These contaminants exceeded non-cancer based health guidelines in air emissions, however, it is unlikely that exposure to these chemicals would cause an individual to develop Alzheimer's.

Asthma

Residents also expressed concern over asthma and its relationship to industrial emissions in the area. Asthma is a chronic conditions in which the airways in the lungs undergo changes when stimulated by allergens or other environmental triggers that cause patients to cough, wheeze, and experience shortness of breath. Asthma has become increasingly more common in the last few decades, and has increased dramatically in all age groups except older men.

There are a number of factors that are believed to contribute to developing asthma, many of which are from indoor exposures. These factors include exposures to:

Allergens: such as animal dander, pollen, molds, and fungi, dust mites, cockroaches, and hay fever.

Pollution and Cigarette Smoking: Pollution has been associated with the development of asthma and asthma related hospitalization. Specific pollutants targeted for their role in triggering asthma include: diesel fumes, sulfur dioxide (power and paper industries) and nitrogen dioxide (car exhaust and gas ovens inside the home). Nitrogen dioxide released from gas ovens may pose a particularly high risk for asthma in children. Cigarette smoke exposure in the home increases the risk for asthma and asthma related emergency room visits in children. This risk is transmitted to the unborn children of smoking mothers.

Food Allergies: certain preservatives found in foods can cause asthma attacks. Two of the most common are monosodium glutamate (MSG), and sulfites.

Heredity: One third of asthmatics have a family member who is also asthmatic.

Exercise: in 40-90% of people with asthma can have an asthma attack from exercising, especially in cold, dry air.

Infections: certain bacterial infections, most notably Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus, and respiratory syncytial virus can cause onset of asthma.

Contributing medical conditions: gastrointestinal reflux disease (GERD), the cause of heartburn, is common among many asthmatic patients and is common in children with hard-to-control asthma. Additionally, about half of people who have asthma also have sinus abnormalities or sinusitis.

Urban life: studies indicate that asthma is more common in residents living in urban areas. This could be because of the age of housing, rodents and cockroaches. Also, air quality in urban areas is often less desirable than in less developed areas.

Occupation: Highly trained athletes are more susceptible to asthma. Also, a large number of occupational allergens in the workplace can affect workers. A few of these include: isocyanates (used in the manufacture of polyurethane, paints, steel, and electronics); trimelletic anhydrides (used in plastics and epoxies); western red cedar, oak, redwood, and mahogany; metal salts (platinum, nickel, and chrome) and metal working fluids; vegetable dusts (soybean, grains, flour, cotton, and gums); biological agents (Bacillus subtillus, pancreatic enzymes); xylanase used in the baking industry; pharmaceutical agents (penicillin, phenylglycine acid chloride); and some red dyes.

Obesity: people who are overweight may be at higher risk for asthma.

While the possibility that asthma is related to emissions from this facility, it is difficult to associate the contaminants present at this site and the onset of asthma. There are quite a number of factors that can contribute to the onset of asthma, many of which are related to the conditions a person is exposed to in his home. The only contaminant that has been associated with the onset of asthma and which exceeded non-cancer health guidelines was chromium. Research has documented an association between employees acutely exposed to very high levels of chromium VI (most toxic form of chromium). An association between residents exposed to chromium in ambient air and asthma has not been documented in scientific literature.

The cause of asthma onset is complicated and may be related to a number of different factors. ATSDR cannot determine whether or not asthma could be caused by the concentrations of contaminants reported at this site. However, high particulate dust concentrations in air may exacerbate asthma and make breathing more difficult. In other words, days where particulate concentrations of dust in air are high may aggravate asthmatic residents, but most likely, does not cause asthma to develop. Although some people may be more sensitive to particulate aggravation, total suspended particulates (TSP) reported from monitors in the area were well within EPA suggested particulate concentration guidelines. TSP levels in ambient air are not expected to cause adverse health effects for residents.

References:

Asthma. National Centers for Environmental Health. Center for Disease Control and Prevention.1999. http://www.cdc.gov/nceh/asthma/default.htm

Asthma. American Lung Association, 2000. http://www.lungusa.org/

Sinusitis

Residents reported that sinus problems were another health issue they believe may be caused by exposure of emissions from the Solite facility. Because particular sinus conditions were not identified, sinusitis was chosen for discussion here. Sinusitis is the inflammation of the sinuses. Chronic sinusitis, sinusitis lasting for longer than three weeks, is very common and effects an estimated 32 million people in the United States. Sinuses are cavities within the skull or bones of the head surrounding the nose. Each sinus has an opening into the nose for free exchange of air and mucus. Anything that causes the tissue in the nose to swell-an infection or allergic reaction- can affect the sinuses. Air trapped within an obstructed sinus, along with pus or mucus, may cause pressure in the sinuses which can cause a great deal of discomfort and pain.

Most cases of acute sinusitis (lasting two weeks or less) are preceded by virus-induced "colds". When sinus opening swell shut and mucus can't drain, bacteria from the respiratory tract multiple and infect the sinuses. Fungal infections can also cause sinusitis, as well as chronic inflammation of the nasal passages (rhinitis). Rhinitis can be complicated by allergies, humidity, cold air, alcohol, and perfume.

Chronic sinusitis can last month or even years. Chronic sinusitis is most frequently associated with allergies and asthma. Inhalation of dusts, mold, and pollen often cause an allergic reaction which can cause sinusitis. Damp weather, especially in northern temperature climates, or pollutants in the air and in buildings can affect people with chronic sinusitis. Sinusitis is more common in patients with immune deficiency and asthmatics.

People with sinusitis can find partial relief from installing humidifiers in their homes, avoiding cigarette smoke, and heavy air pollution. People whose sinusitis may be related to allergic reactions to dust, molds, and fungi should see a doctor.

Sinusitis, like asthma, may be aggravated in this community by exposures to high concentrations of particulates in air. There is no evidence that particulate concentrations in air near the facility exceed EPA particulate guidelines, however, more sensitive individuals may still be affected. Residents may also be more susceptible to sinusitis in harvest months when soils are disturbed and a higher than normal concentration of dusts are in the air. ATSDR researched scientific literature to determine whether or not contaminants exceeding non-cancer risk based guidelines have been associated with sinusitis. Although cadmium and chromium do not appear to be associated with sinus aggravation, arsenic has been associated with rhinitus (runny nose, itching, sneezing). This relationship was found in employees exposed occupationally to very high levels of arsenic, but this effect has not been observed in residential settings. Arsenic has not been associated with sinusitis or sinus related difficulties. No data exists for residential, chronic exposure to very low levels of arsenic and its relationship, if any, to sinusitis. ATSDR finds data inconclusive about this association.

References:

The National Institute of Allergy and Infectious Disease of the National Institutes of Health. Fact Sheet. Sinusitis. August 1996. Last revised April 1999. http://www.niaid.nih.gov/factsheets/sinusitis.htm

Neurological illness

Neurological illnesses of concern were unspecified by residents. However, ATSDR researched contaminants of concern and their relationship, if any, to the development or neurological illnesses.

Cadmium and chromium exposure have not been associated with neurological illness. However, inorganic arsenic can cause serious neurological illnesses and abnormalities. These effects have been observed primarily with exposure to very high concentrations orally, either through eating or drinking contaminated food or water. Lower level exposures have been associated with less severe neurological abnormalities, but these studies have been of long-term ingestion of residential drinking water. The drinking water wells in this community did not have reported levels of arsenic. The only studies that show an association between inhalation of arsenic and neurological illness is through occupational exposures in the workplace. However, these were acute exposures to extremely high levels of arsenic. No studies are available that associate arsenic in residential air with neurological illness. While it is true that arsenic concentrations in air are elevated at certain times of the year in this community, the levels of exposure will most likely not cause neurological damage to residents breathing ambient air.

References:

ATSDR Toxicological Profiles. Arsenic (2001), Cadmium, Chromium.

Cancer

Residents in many industrial areas are concerned about whether or not contaminants contained in industrial emission can cause them to develop cancer. Residents near the Carolina Solite facility are also concerned about cancer in their community and how it may be cause by emissions from the facility. The specific cancers that residents have expressed concern about include cancers of the brain, kidney, colon, lung, skin, and leukemia. There are a number of environmental/chemical causes linked to cancers in different locations in the body.

ATSDR has determined the following:

Brain Cancer:

Brain cancers have been associated with occupational exposure to polyvinyl chloride, electromagnetic field radiation, head injuries, and aspartame (sugar substitute). However, brain cancer has not been related to the contaminants of concern detected in this community.

References:

Murphy, GP, LB Morris, and D Lange. Informed Decisions; The Complete Book of Cancer Diagnosis, Treatment, and Recovery. Viking Productions, 1997. ISBN ID#: 0670853704

American Cancer Society. Brain Cancer. 2000. http://www.cancer.org

Colon Cancer:

Colon cancer has no known environmental causes.

References:

American Cancer Society. Colon Cancer. 2000. http://www.cancer.org

Kidney Cancer:

Kidney cancer has been related to exposures to asbestos, smoking, taking painkillers, some kidney damaging diseases, and cadmium exposure. Cadmium is a contaminant of concern in this community, and has been related to kidney cancer. Some studies have attempted to substantiate an association between oral exposure (eating/drinking) high levels of cadmium and kidney cancer. In this community, oral exposure through groundwater is not a health threat at this time. However, it is important to investigate cadmium soil levels to determine if residents may be exposed to cadmium through private vegetable gardens. In ATSDR's investigation, neither human nor animal studies have provided sufficient evidence to determine whether or not cadmium is a carcinogen that causes kidney cancer. Although arsenic has been inconclusively linked to kidney cancer in some studies, this exposure was oral only, not through ambient air. The contaminants of concern in this community have not been associated with kidney cancer through inhalation exposure.

References:

Agency for Toxic Substances and Disease Registry. Toxicological profile for cadmium. U.S. Department of Health and Human Services. Update, July 1999.

American Cancer Society. Kidney Cancer. 2000. http://www.cancer.org

Leukemia:

ATSDR did not identify any contaminants that exceeded cancer risk based guidelines that have been associated with leukemia. However, the American Cancer Society (2000) reports that long term exposure to herbicides or pesticides among farmers and children has been associated with the development of leukemia. Some of the specific herbicides and pesticides studied in epidemiologic studies include: previous use of dichlorodiphenyltrichloroethane (DDT), chlorophenoxy herbicides, triazine herbicides, alachlor (acetanilide herbicides), organophosphates including crotoxyphos, dichlorvos, and famphur, pentachlorophenol, and even household pesticides. Other factors that have been associated with leukemia in scientific studies include exposure to high-dose radiation exposure (i.e., atomic blast or nuclear reactor accident), and smoking. Hereditary factors appear to be the strongest risk factor. People with a first degree relative (mother, father, brother, sister) have a much higher risk of developing leukemia than do people without a close relative with the disease.

References:

Murphy, GP, LB Morris, and D Lange. Informed Decisions; The Complete Book of Cancer Diagnosis, Treatment, and Recovery. Viking Productions, 1997. ISBN ID#: 0670853704

American Cancer Society. Leukemia. 2000. http://www.cancer.org

Heacock et al. Childhood cancer in the offspring of male sawmill workers occupationally exposed to chlorophenate fungicides. Environ Health Perspect. June 2000; 108(6):499-503.

Meinert, et al. Leukemia and non-Hodgkin's lymphoma in childhood and exposure to pesticides: results of a register-based case-control study in Germany. Am J Epidemiol. April 1, 2000;151(7):639-46;discussion 647-50.

Infante-Rivard, et al. Risk of childhood leukemia associated with exposure to pesticides and with gene polymorphisms. Epidemiology. September 1999;10(5):481-7.

Cantor KP, Silberman W. Mortality among aerial pesticide applicators and flight instructors: follow-up from 1965-1988. Am J Ind Med. August 1999;36(2):239-47.

Jaga, K and Brosius D. Pesticide exposure: human cancers on the horizon. Rev. Environ Health. Jan-March 1999; 14(1):39-50.

Schrienemachers, DM. Cancer mortality in four northern wheat producing states. Environ Health Perspect. September 2000;108(9):873-81.

Dich et al. Pesticides and Cancer. Cancer Causes Control. May 1997;8(3):420-43.

Sathiakumar N, Delzell E. A review of epidemiologic studies of triazine herbicides and cancer. Crit Rev Toxicol. November 1997;27(6):599-612.

Leet, et al. Cancer incidence among alachlor manufacturers. Am J Ind Med. September 1996;30(3):300-6.

Morrison et al. Herbicides and Cancer. J Natl cancer Inst. December 16, 1992;84(24):1866-74.

Brown, et al. Pesticide exposures and other agricultural risk factors for leukemia among men in Iowa and Minnesota. Cancer Res. Oct 15, 1990;50(20):6585-91.

Roberts, HJ. Pentachlorophenol-associated aplastic anemia, red cell aplasia, leukemia, and other blood disorders. J Fla Med Assoc. Feb 7, 1990;77(2):86-90.

Lung Cancer:

Lung cancer has been associated with workers exposed occupationally to very high levels of arsenic and chromium. However, there is no scientific evidence that residential exposure to low levels of arsenic and chromium causes lung cancer. The lowest level workers were exposed to that was associated with lung cancer was 0.04 mg/m³ (milligrams per cubic meter of air) for chromium and 0.01 mg/m³ of arsenic. The lowest chromium cancer effect level (CEL) of .04 mg/m³ was determined from occupational exposures in males who worked in the production of ferrochromium alloy for between 1 and 49 years. This level is approximately 8000 times the highest peak level of chromium observed in air sampling in the Solite vicinity. It has been reported that the lowest cancer effect level for arsenic is .01 mg/m³ in workers exposed for 1-30 years, which is 400 times the highest spike of arsenic detected by air monitors in the area in 1999. Arsenic has also been related to lung cancer through oral exposure at highly concentrated levels, but no arsenic was detected in residential water wells. Smoking cigarettes can exacerbate irritation of lung tissue and accelerate the development (if not cause the development) of lung cancer in workers exposed to arsenic and chromium. Soil concentrations of chromium and arsenic will be analyzed in a future health consultation. Residents may have concerns about eating vegetables grown in soils contaminated with metals. Potential health effects from oral exposures to levels of metals (if they are elevated) will be discussed in that document. It is unlikely that levels of arsenic and chromium detected in ambient air in the Solite vicinity could result in lung cancer in residents. There is no evidence in scientific literature that concentrations of these contaminants in residential air has resulted in an increase in lung cancer.

References:

Agency for Toxic Substances and Disease Registry. Toxicological profile for arsenic. U.S. Department of Health and Human Services. April 1993. Update. Report No. TP-92-02

Agency for Toxic Substances and Disease Registry. Chromium, Toxicological profile for chromium. U.S. Department of Health and Human Services. August 1998.

Langard, et al. Incidence of cancer among ferrochromium and ferrosilicon workers. Br J Ind Med 37:114-120.

Jarup, et al. 1989. Cumulative arsenic exposure and lung cancer in smelter workers: A dose-response study. A, J. Ind. Med. 15:31-41.

Skin cancer:

Arsenic and chromium can cause skin rashes if people come into direct contact with contaminated soil or pure arsenic or chromium. However, they are not known to cause skin cancer or to damage internal organs through skin contact. Skin contact with cadmium is not known to affect the health of people or animals because virtually no cadmium can enter the body the skin under normal circumstances (i.e., without exposure to very high concentrations for long times of exposure to skin that is not damaged). The only environmental risk factor identified by the American cancer society is too much exposure to ultraviolet (UV) radiation. Residents who farm and spend a great deal of time outdoors during harvest and planting seasons may be exposed to a great deal of UV radiation, and could be at higher risk for developing skin cancer. Farmers should take precautions to protect their skin when they are outdoors and in direct sunlight. It is unlikely that residents are exposed to high enough concentration of arsenic and chromium to cause skin irritation (this was not listed as a community concern), and very unlikely that environmental contaminants present in the area would cause skin cancer in residents.

References:

Agency for Toxic Substances and Disease Registry. Toxicological profile for arsenic. U.S. Department of Health and Human Services. April 1993. Update. Report No. TP-92-02

Agency for Toxic Substances and Disease Registry. Chromium, Toxicological profile for chromium. U.S. Department of Health and Human Services. August 1998.

Agency for Toxic Substances and Disease Registry. Toxicological profile for cadmium. U.S. Department of Health and Human Services. Update, July 1999.

American Cancer Society. Skin Cancer. 2000. http://www.cancer.org

Cancer Information for Residents

The following information was made possible with excerpts from fact sheets distributed by the American Cancer Society and the National Cancer Institute. Hopefully, this information will help residents understand each type of cancer, its symptoms, and risk factors, a little better.

What is Cancer?

Cancer is a group of many related diseases. All forms of cancer involve out-of-control growth and spread of abnormal cells. Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person's life, normal cells divide more rapidly until the person becomes an adult. After that, normal cells of most tissues divide only to replace worn-out or dying cells and to repair injuries.

Cancer cells, however, continue to grow and divide, and can spread to other parts of the body. These cells accumulate and form tumors (lumps) that may compress, invade, and destroy normal tissue. If cells break away from such a tumor, they can travel through the bloodstream, or the lymph system (part of the body that fights off infection) to other areas of the body. There, they may settle and form "colony" tumors. In their new location, the cancer cells continue growing. The spread of a tumor to a new site is called metastasis. When cancer spreads, though, it is still named after the part of the body where it started. For example, if prostate cancer spreads to the bones, it is still prostate cancer, and if breast cancer spreads to the lungs it is still called breast cancer.

Leukemia, a form of cancer, does not usually form a tumor. Instead, these cancer cells involve the blood and blood-forming organs (bone marrow, lymphatic system, and spleen), and circulate through other tissues where they can accumulate. It is important to realize that not all tumors are cancerous. Benign (noncancerous) tumors do not metastasize and, with very rare exceptions, are not life-threatening.

How is cancer detected?

Cancer is often detected after a patient notices changes in their normal body functions, pain, or discomfort. A doctor does tests (called screening) because a patient is having symptoms or because it is routine to screen for some conditions. An example of a routine screening for cancer is a Pap smear, at a woman's annual gynecologic exam. Screening may involve a physical exam, lab tests, and/or procedures to look at internal organs, either directly or indirectly. During a physical exam, the doctor looks for anything unusual and feels for any lumps or growths. Examples of lab tests include blood and urine tests, the Pap test (microscopic examination of cells collected from the cervix), and the fecal occult blood test (to check for hidden blood in stool). Internal organs can be seen directly through a thin lighted tube (such as a sigmoidoscope, which lets the doctor see the rectum and the lower part of the colon) or indirectly with x-ray images (such as mammograms to check the breasts).

Doctors consider many factors before recommending a screening test. They weigh factors related to the individual, the test, and the cancer that the test is intended to detect. For example, doctors take into account the person's age, medical history and general health, family history, and lifestyle. These factors greatly influence a person's health and well-being. In addition, they assess the accuracy and the risks of the screening test and any followup tests that may be necessary. Doctors also consider the effectiveness and side effects of the treatment that will be needed if cancer is found. People may want to discuss any concerns or questions they have with their doctors, so they can weigh the pros and cons and make an informed decision about whether to have a screening test.

What are the symptoms of cancer?

A symptom is an indication of disease, illness, injury, or that something is not right in the body. Symptoms are felt or noticed by a patient, but not easily observed by anyone else. For example chills, weakness, achiness, shortness of breath, and a cough are symptoms that might indicate pneumonia. A sign is also an indication of illness, injury, or that something is not right in the body. But, signs are defined as observations made by a physician, nurse or other health care professional. Fever, rapid breathing rate, abnormal breathing sounds heard through a stethoscope are signs that may indicate pneumonia.

The presence of one symptom or sign may not provide enough information to suggest a cause. For example a rash in a child could be a symptom of a number of things including poison ivy, a generalized infection like rubella, an infection limited to the skin, or a food allergy. But, if the rash is associated with a high fever, chills, achiness and a sore throat, then all of the symptoms together provide a better picture of the illness. In many cases, a patient's signs and symptoms do not provide enough clues to determine the cause of an illness, and medical tests such as x-rays, blood tests, or a biopsy may be needed.

Although some generalized symptoms and signs such as unexplained weight loss, fever, fatigue, or lumps may be due to several types of cancer, they are often caused by other types of diseases. Other signs and symptoms are relatively specific to a particular type of cancer. It is important to see your doctor so they can correctly determine if your symptoms are an indication of cancer or something less serious.

How is cancer treated?

Treatment choices for the person with cancer depend on the stage of the tumor, that is, if it has spread and how far. Treatment options may include surgery, radiation, chemotherapy, hormone therapy, and immunotherapy:

• Surgery is the oldest form of treatment for cancer. Before the discovery of anesthesia and antisepsis (methods such as sterilization of instruments to prevent infection), surgery was performed with great discomfort and risk to the patient. Today surgery offers the greatest chance for cure for many types of cancer. About 60% of people with cancer will have some type of surgery, or operation.
• Radiation therapy uses high-energy particles or waves, such as x-rays or gamma rays, to destroy or damage cancer cells.
• Chemotherapy is the use of medicines (drugs) to treat cancer. Systemic chemotherapy uses anticancer drugs that are usually given into a vein or by mouth. These drugs enter the bloodstream and reach all areas of the body, making this treatment potentially useful for cancer that has spread.
• Hormone Therapy is treatment with hormones, drugs that interfere with hormone production or hormone action, or surgical removal of hormone-producing glands to kill cancer cells or slow their growth.
• Immunotherapy is the use of treatments that promote or support the body's immune system response to a disease such as cancer.
• Alternative and Complementary Therapies

Unproven therapy is any therapy that has not been scientifically tested and approved. Use of an unproven therapy instead of standard therapy is called alternative therapy. Some alternative therapies have dangerous or even life-threatening side effects. For others, the main danger is that a patient may lose the opportunity to benefit from standard therapy. Complementary therapy, on the other hand, refers to therapies used in addition to standard therapy. Some complementary therapies may help relieve certain symptoms of cancer, relieve side effects of standard cancer therapy, or improve a patient's sense of well-being. The American Cancer Society recommends that patients considering use of any alternative or complementary therapy discuss this with their health care team.

What are risk factors for cancer and how can cancer be prevented?

A risk factor is anything that increases a person's chance of developing a disease such as cancer. Different cancers have different risk factors. For example, smoking is a risk factor for cancers of the lungs, mouth, throat, larynx, bladder, and several other organs. It is important to remember, however, that these factors increase a person's risk but do not always "cause" the disease. Many people with one or more risk factors never develop cancer, while others with this disease have no known risk factors. It is important, however, to know about risk factors so that appropriate action can be taken, such as changing a health behavior or being monitored closely for a potential cancer.

All cancers caused by cigarette smoking and heavy use of alcohol could be prevented completely. The ACS estimates that in 2000 about 171,000 cancer deaths are expected to be caused by tobacco use, and about 19,000 cancer deaths may be related to excessive alcohol use, frequently in combination with tobacco use. Many cancers that are related to dietary factors could also be prevented. Scientific evidence suggests that up to one-third of the 552,200 cancer deaths expected to occur in the US in 2000 are related to nutrition and other lifestyle factors and could also be prevented. Certain cancers are related to viral infections-for example, hepatitis B virus (HBV), human papillomavirus (HPV), human immunodeficiency virus (HIV), human T-cell leukemia/lymphoma virus-I (HTLV-I), and others-and could be prevented through behavioral changes. In addition, many of the 1.3 million skin cancers that are expected to be diagnosed in 2000 could have been prevented by protection from the sun's rays.

Regular screening examinations by a health care professional can result in the detection of cancers of the breast, colon, rectum, cervix, prostate, testis, oral cavity, and skin at earlier stages, when treatment is more likely to be successful. Self examinations for cancers of the breast and skin may also result in detection of tumors at earlier stages. The screening-accessible cancers listed above account for about half of all new cancer cases. The 5-year relative survival rate for these cancers is about 80%. If all Americans participated in regular cancer screenings, this rate could increase to 95%.

Brain and Spinal Cord Cancers (Central Nervous System)

What does the Central Nervous System (CNS) consist of?

The main parts of the central nervous system (CNS ) are the brain and spinal cord. The main areas of the brain include the cerebral hemispheres, basal ganglia, cerebellum, and brain stem Each of these parts has a special purpose. Tumors of different parts of the CNS disrupt different functions and cause different symptoms. These symptoms are not specific for brain cancer and may be caused by any disease involving that particular location within the brain. Also, tumors in different areas of the CNS may be treated differently and have a different prognosis (survival).

How common is brain cancer?

The American Cancer Society estimates that 16,500 malignant tumors of the brain or spinal cord (9,500 in men and 7,000 in women) will be diagnosed during 2000 in the United States. Approximately 13,000 people (7,100 men and 5,900 women) will die from these malignant tumors. This type of cancer accounts for approximately 1.4% of all cancers and 2.4% of all cancer-related deaths. Both adults and children are included in these statistics.

What are the symptoms of brain cancer?

Brain or spinal cord cancer is initially suspected because of the symptoms it causes. Symptoms usually occur gradually and become worse over time. However, sometimes these symptoms happen suddenly, like a stroke.

In many children, epileptic seizures are the first symptom of a brain tumor. Only a few epileptic seizures in children are caused by brain tumor, but a neurologist should be consulted in any child who has a seizure to determine what further evaluation is necessary.

Whether a brain cancer is detected early usually depends on its location within the brain. Cancers located in more important areas of the brain may cause symptoms earlier than those located in less important areas of the brain. Brain and spinal cord tumors often interfere with the specific functions of the region they develop in. For example, spinal cord tumors often cause numbness and/or weakness of both legs, and tumors of the basal ganglia typically cause abnormal movements and abnormal positioning of the body.

Tumors within any part of the brain may cause pressure to rise within the skull. Increased pressure within the skull may cause headache, nausea, vomiting, or blurred vision. Headache is a common symptom of brain tumor, occurring in about 50% of children with brain tumors. In some children increased intracranial pressure causes crossed eyes and double vision. In others, it may cause visual loss. The physician can often identify the presence of increased intracranial pressure by looking in the child's eyes for papilledema (swelling of the optic nerve).

In the school-age child, a decline in school performance, fatigue, personality changes, and complaints of vague intermittent headaches are common. In the first few years of life, irritability, loss of appetite, developmental delay, and regression of intellectual and motor abilities are frequent signs of increased pressure. In the very young infant increasing head size with or without a bulging fontanelles (soft spots of the skull), persistent vomiting, and failure to thrive are often characteristic.

None of these symptoms are specific for brain or spinal cord cancer and they all may be caused by other disorders.

What can cause brain cancer?

Environmental Risk Factors: The only established environmental risk factor for brain

tumors is ionizing radiation (the kind of radiation used in x-ray machines and to treat tumors). Before the risks of radiation were recognized (over 50 years ago), children with ringworm of the scalp (a fungal infection) often received low-dose radiation therapy which substantially increased the risk of brain tumors in later life. Today, most radiation-induced brain tumors are caused by radiation to the head given for the treatment of other cancers.

Other environmental factors such as exposure to polyvinyl chloride (an odorless gas used in the manufacturing of plastics), exposure to aspartame (a sugar substitute), exposure to electromagnetic fields from cellular telephones or high-tension wires, and previous injury to the head have been suggested as risk factors. Most researchers in this field agree that no conclusive evidence exists that clearly implicates these factors.

Family history of brain cancer: Rare cases of brain and spinal cord cancers run in families. In general, persons with familial cancer syndromes have multiple tumors that occur when they are young. Some of these families have well-known disorders. Recently, researchers have found that gene mutations that cause some rare inherited syndromes (like neurofibromatosis, tuberous sclerosis, Li-Fraumeni, and Von Hippel- Lindau) are associated with an increased risk of developing some central nervous system cancers.

Uninherited gene mutations

Colon and Rectal Cancers

Where do colon and rectal cancers develop?

Colon and rectal cancer develop in the digestive tract, which is also the gastrointestinal, or GI, tract. The colon is the first part of the large bowel, or large intestine and is connected to the small intestine. The first part of the large bowel, called the colon continues to absorb water and mineral nutrients from the food matter and serves as a storage place for waste matter. The waste matter left after this process goes into the rectum, the final 6 inches or so of the large bowel. From there it passes out of the body through the anus. The digestive system processes food for energy and rids the body of solid waste matter (fecal matter or stool).

How common are colon and rectal cancers (also called colorectal cancer)?

Among men and women, colorectal cancer is the third most common cancer diagnosed in Americans. About 93,800 new cases of colon cancer (43,400 men and 50,400 women) and 36,400 new cases of rectal cancer (20,200 men and 16,200 women) will be diagnosed in 2000. Colon cancer is expected to be responsible for about 47,700 deaths(23,100 men and 24,600 women) during 2000. About 8,600 people(4,700 men and 3,900 women) will die from rectal cancer during 2000.

What are the symptoms people with colorectal cancers have?

Common signs and symptoms of colorectal cancer include:

• A change in bowel habits
• Diarrhea, constipation, or feeling that the bowel does not empty completely
• Blood (either bright red or very dark) in the stool
• Stools that are narrower than usual
• General abdominal discomfort (frequent gas pains, bloating, fullness, and/or cramps)
• Weight loss with no known reason
• Constant tiredness
• Vomiting

What are the risk factors for colorectal cancer?

Certain things can put a person at higher risk for developing colorectal cancers, such as: a family history of colon or rectal cancers, having had colon or rectal cancer before, a history of intestinal polyps (small growths), history of inflammatory bowel syndrome, aging (90% of colorectal cancers are in people over 50 years old), high fat diets, physical inactivity, and obesity. Some of these risk factors can be controlled and others are genetic (hereditary, or passed down in families) and cannot. However, early detection can greatly increase the chances that a person diagnosed with colorectal cancer will survive the disease (ACS).

Kidney Cancer

What are kidneys and what do they do?

The kidneys are two reddish-brown, bean-shaped organs located just above the waist, one on each side of the spine. They are part of the urinary system. Their main function is to filter blood and produce urine to rid the body of waste. As blood flows through the kidneys, they remove waste products and unneeded water (NCI).

How common is kidney cancer?

The American Cancer Society predicts that there will be about 31,200 new cases of kidney cancer in the year 2000 in this country. About 11,900 people, adults and children, will die from this disease (ACS).

What are the symptoms of kidney cancer?

If the disease is found early, the chances of surviving kidney cancer are very good. Noticing early symptoms often helps in early diagnosis. Blood in the urine is the most common sign of renal cell cancer. Blood in the urine can also be caused by a bladder infection or some other non-cancerous kidney disease. Signs and symptoms of renal cell cancer include: blood in the urine, low back pain (not from an injury), mass or lump in the belly, tiredness, weight loss (rapid, and without a known reason), fever (not from a cold, the flu, or other infection), swelling of ankles and legs, and high blood pressure.

What increases the risk of someone developing kidney cancer?

Risk factors for kidney cancer include:

• Smoking: smoking doubles the risk of getting kidney cancer.
• Overuse of certain painkillers: pain killers containing phenacetin were once popular non-prescription medications, but they have not been available in the United States for over 20 years.
• Asbestos: some studies show a link between exposure to asbestos in the workplace and kidney cancer.
• Cadmium: there may be a link between cadmium exposure and kidney cancer. Also, cadmium may increase the cancer-causing effect of smoking. Workers can be exposed to cadmium in the air from working with products such as batteries, paints, or welding materials.
• Gene changes (mutations): Genes are made up of DNA and are the basic units of heredity. They are the reason we resemble our parents. Changes or mutations in certain genes can increase the risk of developing kidney tumors. Some of these changes are inherited (people with a family history of renal cell cancer have an increased risk) and some can be caused by later damage, for example, by cigarette smoke.
• von Hippel-Lindau syndrome: this disease, caused by an inherited gene mutation (change), increases the chances of renal cell cancer and other types of cancer.
• Tuberous sclerosis: patients who have this disease often have cysts in the kidneys, liver, and pancreas and are more likely to get renal cell cancer.
• Diet and weight: some studies show a link between being overweight, a diet high in fat, and renal cell cancer.
• Long-term dialysis: people who have been on dialysis for a long time may develop cysts in their kidneys that can give rise to renal cell cancer.
• Age: RCC is rare in children and young adults; it is found mostly in adults between the ages of 50-70 years.
• Gender: men are twice as likely to get renal cell cancer as are women.

Chronic Lymphoproliferative and Myeloproliferative Disorders

What is leukemia and how does it effect the body?

Bone marrow is the soft, spongy, inner part of bones. All of the different types of blood cells are made in the bone marrow. In babies, bone marrow is found in almost all the bones of the body. But by the teen-age years, it is found mostly in the flat bones such as those of the skull, shoulder blades, ribs, pelvis, and back bones. Bone marrow is made up of blood-forming cells, fat cells, and tissues that aid the growth of blood cells. Early (primitive) blood cells are called stem cells. These stem cells grow (mature) in an orderly process to produce red blood cells, white blood cells, and platelets. Red blood cells carry oxygen from the lungs to all other tissues of the body. They also carry away carbon dioxide, a waste product of cell activity. A shortage of red blood cells (anemia) causes weakness, shortness of breath, and tiredness.

White blood cells (leukocytes) help defend the body against germs - viruses and bacteria. There are quite a few types (and sub-types) of white blood cells. Each has a special role to play in protecting the body against infection. The three main types of white blood cells are granulocytes, monocytes, and lymphocytes. The suffix - cyte means cell. Platelets are actually pieces that break off from certain bone marrow cells. They are called platelets because they look a little bit like plates when seen under the microscope. Platelets help prevent bleeding by plugging up areas of blood vessels damaged by cuts or bruises.

The lymphatic system consists of lymph vessels, lymph nodes, and lymph fluid. Lymph vessels are like veins except that they carry a clear fluid, lymph, instead of blood. Lymph is composed of excess fluid from tissues, waste products, and immune system cells. Lymph nodes (sometimes called lymph glands) are pea-sized organs found along the lymph vessels. Lymph nodes collect immune system cells. The nodes get bigger when they fight infection. Swollen lymph nodes are not usually serious, especially in children but rarely they can be a sign of leukemia when the cancer has spread outside the bone marrow.

There are four major types of leukemia: acute versus chronic and lymphocytic versus myelogenous. Acute means rapidly growing. Although the cells grow rapidly, they are not able to mature properly. Chronic refers to a condition where the cells look mature but they are not completely normal. The cells live too long and cause a build-up of certain kinds of white blood cells. Lymphocytic and myelogenous (or myeloid) refer to the two different cell types from which leukemias start. Lymphocytic leukemias develop from lymphocytes in the bone marrow. Myelogenous leukemia develops from either of two types of white blood cells: granulocytes or monocytes.

Leukemia is cancer of the white blood cells. This cancer starts in the bone marrow but can then spread to the blood, lymph nodes, the spleen, liver, central nervous system and other organs. In order to understand the different types of leukemia, it is helpful to have some basic knowledge of the blood and lymph systems. Following is an explanation of some of the parts of these systems.

How common is leukemia?

The American Cancer Society predicts that, in the year 2000, there will be about 30,800 new cases of all types of leukemia in this country. Of these, about 12, 500 will be chronic leukemia: 8,100 chronic lymphocytic leukemia (CLL) and 4,400 chronic myelogenous leukemia (CML). The remaining cases are of other chronic types. Chronic leukemia affects mostly older adults. Only about 2% of chronic leukemia patients are children.

What are the symptoms of leukemia?

At least one-fifth of people with chronic leukemia have no symptoms at the time their cancer is diagnosed. Their cancer is diagnosed by blood tests performed during an evaluation some unrelated health problem or during a routine checkup. Even when symptoms are present, they are often vague and nonspecific. Most symptoms of chronic leukemia, such as weakness, fatigue, reduced exercise tolerance, weight loss, fever, bone pain, and pain or a sense of "fullness" in the abdomen (especially after eating a small meal) can also occur with other cancers as well as many noncancerous conditions. Many of the signs and symptoms of chronic leukemia occur because the leukemic cells replace the bone marrow's normal blood-producing cells. As a result, people do not have enough properly functioning red blood cells, white blood cells, and blood platelets.

Other symptoms include:

• Anemia, a shortage of red blood cells, causes excessive tiredness, a "pale" color to the skin, and in more serious cases, shortness of breath.
• Not having enough normal white blood cells increases the risk of infections. Although leukemia is a cancer of white blood cells and patients with leukemia may have very high white blood cell counts, the leukemic cells do not protect against infection the way normal white blood cells do.
• Thrombocytopenia (not having enough of the blood platelets needed for plugging holes in damaged blood vessels) can lead to excessive bruising, bleeding, frequent or severe nosebleeds, and bleeding gums.
• Leukemia cells may spread to other organs and can cause symptoms there. For example, spreading to the brain may cause headaches, weakness, seizures, vomiting, difficulty in maintaining balance, or blurred vision.
• Some patients have bone pain or joint pain caused by leukemic cells spreading from the marrow cavity to the surface of the bone or into the joint.
• Leukemia often causes enlargement of the liver and spleen, organs located on the upper right and upper left side of the abdomen, respectively. Enlargement of these organs may be noticed as a fullness, or even swelling, of the belly. These organs are usually covered by the lower ribs but when they are abnormally large, they can be felt by a doctor.
• Leukemia may spread to lymph nodes. If the affected nodes are close to the surface of the body (for example, lymph nodes on the sides of the neck, in the groin, the underarm areas, and above the collarbone), the patient or health care provider may notice the swelling. Swelling of lymph nodes inside the chest or abdomen may also occur, but can be detected only by imaging tests.

What are the risk factors for developing leukemia?

There are some factors in the environment that are linked to chronic leukemia. For example, high-dose radiation exposure (such as from an atomic blast or nuclear reactor accident) increases the risk of CML but not CLL. Long-term contact with herbicides or pesticides among farmers can increase their risk of CLL. There is some concern about very high-voltage power lines as a risk factor for leukemia. The NCI has several large studies going on now to look into this question. So far, the studies show either no increased risk or a very slightly increased risk. Clearly, most cases of leukemia are not related to power lines. The only known inherited risk factor for chronic leukemia is having first-degree relatives (parents, siblings, or children) who have had CLL. Most people who develop leukemia, however, do not have any of the above risk factors. The cause of their leukemia remains unknown at this time. Because the cause is not known, there is no way to prevent most cases of leukemia. The exception is smoking, which has been shown to increase the risk of leukemia.

Lung Cancer

How common is lung cancer?

Lung cancer is the leading cause of cancer death for both men and women. During the year 2000 there will be about 164,100 new cases of lung cancer in this country. About 156,900 people will die of lung cancer: about 89,300 men and 67,600 women. More people die of lung cancer than of colon, breast, and prostate cancers combined. Lung cancer is fairly rare in people under the age of 40. The average age of people found to have lung cancer is 60.

What are the symptoms of lung cancer?

Symptoms of lung cancer include:

• A cough that does not go away
• Chest pain, often made worse by deep breathing
• Hoarseness
• Weight loss and loss of appetite
• Bloody or rust-colored sputum (spit or phlegm)
• Shortness of breath
• Fever without a known reason
• Recurring infections such as bronchitis and pneumonia
• New onset of wheezing

When lung cancer spreads to distant organs, it may cause:

• Bone pain
• Weakness or numbness of the arms or legs, dizziness
• Yellow coloring of the skin and eyes (jaundice)
• Masses near the surface of the body, caused by cancer spreading to the skin or to lymph nodes in the neck or above the collarbone

What are the risk factors for lung cancer?

Smoking is by far the leading risk factor for lung cancer. More than 8 out of 10 lung cancers are thought to result from smoking. Nonsmokers who breathe the smoke of others also increase their risk of lung cancer. Non-smoking spouses of smokers, for example, have a 30% greater risk of developing lung cancer than do spouses of nonsmokers. Workers exposed to tobacco smoke in the workplace are also more likely to get lung cancer. There are other risk factors for lung cancer besides smoking. People who work with asbestos have a higher risk of getting lung cancer. If they also smoke, the risk is greatly increased. Besides smoking and asbestos, there are a few other risk factors for lung cancer. These include certain cancer-causing agents in the workplace, radon gas, and lung scarring from some types of pneumonia. Also, people who have had lung cancer in the past have a higher chance of having it again and, as mentioned earlier, the risk of lung cancer increases with age. Some studies have shown that the lung cells of women who smoke may develop cancer more easily than those of men. While some people believe that air pollution is a major cause of lung cancer, the truth is that air pollution only slightly increases the risk. Smoking is by far the more important cause. Even so, some people who have never smoked or worked with asbestos still get lung cancer. Since we do not know why this happens, there is no sure way to prevent it.

To receive more detailed cancer information, please contact:

You may want more information for yourself, your family, and your health care provider. The following National Cancer Institute (NCI) services are available to help you.

Telephone Cancer Information Service (CIS)

Provides accurate, up-to-date information on cancer to patients and their families, health professionals, and the general public. Information specialists translate the latest scientific information into understandable language and respond in English, Spanish, or on TTY equipment.

Internet

These web sites may be useful:

• http://www.cancer.gov
  NCI's primary Web site; contains information about the Institute and its programs.
  
• http://cancertrials.nci.nih.gov
  cancerTrials�; NCI's comprehensive clinical trials information center for patients, health professionals, and the public. Includes information on understanding trials, deciding whether to participate in trials, finding specific trials, plus research news and other resources.
  
• http://cancernet.nci.nih.gov CancerNet�; contains material for health professionals, patients, and the public, including information from PDQ® about cancer treatment, screening, prevention, supportive care, and clinical trials; and CANCERLIT®, a bibliographic database.
  
  

E-mail

CancerMail includes NCI information about cancer treatment, screening, prevention, and supportive care. To obtain a contents list, send e-mail to cancermail@icicc.nci.nih.gov with the word "help" in the body of the message.

Fax

CancerFax® includes NCI information about cancer treatment, screening, prevention, and supportive care. To obtain a contents list, dial 301-402-5874 from a fax machine hand set and follow the recorded instructions

Evaluation of cancer risk for contaminants of concern

Ambient air metals concentrations were measured by the North Carolina Department of Environment and Natural Resources (NC DENR). Arsenic, cadmium, and chromium were chosen for risk analysis because elevations were detected in ambient air in 1999 monitoring efforts, and these contaminants exceeded ATSDR comparison values (Cvs) in residential air. Arsenic generally ranges from 1 to 30 ng/m³ (nanograms per cubic meter) in background levels of air [5]. Cadmium is generally present in ambient air at approximately 5 ng/m³, but has been detected at levels up to 500 ng/m³ near cadmium emitting facilities [7]. Chromium levels in ambient air generally range from less than 10 ng/m³ to 30 ng/m³ [23]. While the levels detected generally fall within acceptable ranges, these contaminants were detected above ATSDR CVs The levels of arsenic and cadmium detected in residential air were usually at or slightly above ATSDR's Cv for the Cancer Risk Evaluation Guide (CREG). There is no ATSDR CREG for chromium. The CREG represents a very conservative level at which ATSDR believes is safe for exposure. Initial screening with CREGs are based on continuous air exposure for a lifetime (estimated at 70 years).

Cancer risk evaluation usually involves a more realistic exposure scenario using site-specific conditions, if known. However, the evaluation results should NOT be used to predict the incidence of cancer. An increase in cancer risk is often indiscernible in a small population. For example, if the increase in cancer risk is calculated to be 2 cases per 100,000, then the risk for Stanly county, which has approximately 53,000 people, would be the probability of 1.06 additional cases. If we further investigate the two mile area around the Solite facility, which has approximately 3500 people, that increase in risk is almost indiscernible, less than 0.1 cases in the population of interest. However, that number does not mean that an extra 0.1 cases will be diagnosed, it means there is a potential that an additional tenth of a case could be diagnosed as a result of certain environmental exposures. Risk is most often influenced by a number of factors besides environmental exposures, such as lifestyle behaviors (smoking, diet, exercise), age, gender, and hereditary factors. The additional factors can "trigger" predispositions to certain forms of cancer.

Assumptions used in the cancer risk evaluation of arsenic, cadmium, and chromium in ambient air are as follows:

• Exposure duration was assumed to be 70 years total. This number was used here because the most conservative of ATSDR's CVs are based on 70 year, or lifetime, exposure. This number is considered conservative because census data indicate that people in the vicinity of the Solite plant generally stay at their residences for an average of 16 years, and that the plant has been in operation for 53 years (residents could only have been exposed for 53 years). This analysis estimates risk for adults living 70 years with constant exposure by combining contact rate, body weight, and duration of exposure for adults. Adults were assumed to weigh 70 kg and breathe 20 cubic meters of air per day for 70 years.



• The frequency of exposure is also very conservative, and was assumed to be 365 days per year of continuous exposure. This estimate is highly unlikely for people who spend time away from home attending school or working regularly outside their homes.



• The Cancer Slope Factors for inhalation were obtained from the Environmental Protection Agency in July 2000. Inhalation slope factors were obtained from ATSDR.

The following table presents the results of the risk analysis. The level of contaminants measured at each station in the Solite area are presented in micrograms per cubic meter (g/m³), converted from the original reporting measurement of nanograms per cubic meter (ng/m³). The average concentration and range of samples represented in each area are identified, and the results are presented as a potential increase in cancer of 1 case per 100,000 people. These results suggest that all levels detected within residential areas indicate no apparent increase in cancer risk from exposure to each individual contaminant. Because this estimate of risk is very conservative, it is highly likely that actual risk is much lower. In conclusion, using ATSDR cancer risk guidelines, exposure to ambient air is unlikely to result in increased cancer risk in residential areas surrounding Carolina Solite. This information is based on data provided for sampling occurring between January and December 1999. This assessment does not account for historical emissions nor does it make cancer risk predictions about future emissions.

Cancer risk calculations based on contaminant concentrations at each air monitoring site

Contaminant averages for tot¹ g/m³= Micrograms per cubic meter

² Avg.= risk calculated with the average ambient air concentration of a metal at a particular site

³ Max.= risk calculated with the maximum ambient air concentration of a metal at a particular site

⁴ Arsenic at the Solite Hill station had a single spike out of 169 samples which resulted in a cancer risk that was equal to 1/10,000 people, a level that ATSDR deems "low increased risk". However, this level would have to be present frequently in order to present low increased risk to resident, which it is not.

Contaminant averages for total samples collected and cancer risk calculations

The Agency for Toxic Substances and Disease Registry (ATSDR) issued the public health assessment draft for a 30-day public comment period ending May 12, 2001. A summary of the comments received and ATSDR responses on the Public Comment Petitioned Health Assessment for the Carolina Solite Corporation, dated March 12, 2001 are summarized below:

1. Comment: Page 1
   "On Page 1 in the Summary Section of the report, the ATSDR states that it is "unable to assess past exposures because no historical environmental sampling data exists. No conclusions about past exposure and resulting health conditions can be reached without historical data". Two (2) papers published by Dr. Shy (references follow and are attached) address the lack of an association between emissions from the facility and adverse respiratory problems in the community."
   
   ATSDR Response:
   
   ATSDR obtained a copy of these studies and concluded the following:
   
   
   1. "Historical data" in the context used in the document was intended to address residential concerns of facility emissions dating back to when the facility began operations, before many of the new pollution controls were installed and before many of the current regulations for pollution control were established. The data mentioned in comment 1 were collected in the 1990s.
      
      
   2. ATSDR evaluated particulate matter (the basis of these studies) data collected by the state of North Carolina both when the facility was burning hazardous waste derived fuel (HWDF) and when it changed the fuel to recycled oil. This evaluation is presented both in this document and also the second PHA released for this community.
      
      
   3. Aquadale was never conclusively identified as the location for the "rural hazardous waste incinerator" in the studies.
      
      
   4. The data are not conclusive for the residents of the hazardous waste incinerator (HWI) community. One study states that "Although the slight but significantly higher odds of having chronic respiratory symptoms among residents of the HWI community disappeared when we pooled the hazardous waste comparison population with the other two comparison populations, the result from the pooled analysis is not necessarily the correct one." In other words, the levels of respiratory symptoms were significantly higher in the residents in the HWI community than the control community for the HWI community. Both of these were rural communities. However, when compared to the other two communities used as controls, these differences lost their significance. Because the other two communities were urban or suburban communities, ATSDR fails to recognize them as appropriate for direct comparison with the rural affected community. Urban and suburban communities are more likely to be exposed to respiratory stressors than rural communities, therefore rural communities should only be compared to rural communities. In this case, when the control and study population for HWIs were compared, a significant result was observed.
      
      
   5. Assuming this is the Abermarle facility, the data have limitations. The most important is that the air quality study was conducted for 35 successive days of the year, and "to the extent that this period of time is not representative of longer-term air quality in these communities, [the researchers] may not be detecting differences that actually exist." Also, the HWI was not using HWDF in the first year of the study, thus "[the researchers'] first-year results are not applicable to measuring acute respiratory effects from the burning of liquid hazardous wastes..." These limitations may affect the usefulness of the data in evaluating adverse health effects from exposure to HWDF. Additionally, the time frame of the study for the study years were not collected for a significant duration to account for seasonal variation in wind direction, wind speed, etc.
      
      
2. Comment: Page 6
   
   
   1. "On Page 6 in the Air Section, the ATSDR states "Upon investigation, ATSDR determined that during 1999 the highest concentration of arsenic could not be clearly associated with harvest and summer planting months when soils are disturbed. In Stanly county, the three largest crops are soybeans, cotton, and corn. These crops are usually planted between April and June, and harvested in September or later..."
      
      The ATSDR has ignored the three largest crops in Stanly county. In addition, the Agency has not considered other types of crops that could have somewhat different planting and harvest schedule which could correspond with the peak ambient air concentrations. The ATSDR also has focused its report simply on the use of monosodiummethylarsenate and disodiummethylarsenate. Additional investigation of the use of other arsenate-containing products that may be used in the farming practices should be considered. Also, the text suggests that the agency has not investigated other farming activities during which the soil could be disturbed and thus, may correspond with the peak ambient air concentrations."
      
      

      ATSDR Response:

      ATSDR addressed the most common crops in Stanly County. Comment 2 quotes the sentence in which these crops were mentioned in the text. ATSDR contacted Mr. AC York at the North Carolina Department of Agriculture for specific information about the most common pesticides and herbicides used in this county. Mr. York explained the process and verified the times of year these crops were planted, the periods in the growth season that these plants were treated with herbicides and pesticides, and the time of the year the crops were harvested. All three of the most common crops are planted between April and June, and harvested in September or later. The peaks of arsenic found in air were detected between those months, when soils were not being disturbed for planting or harvesting, and when no scheduled applications of the two herbicides containing the greatest weight of arsenic were applied.

      ATSDR did not make any conclusions regarding this trend, but considered it important to mention. In fact, ATSDR concluded that "detected levels of arsenic in air are not expected to result in adverse health effects".

   2. "Also on page 6, the ATSDR states that "[C]hromium is not a common ingredient in agricultural products and a potential source besides the Solite facility has not been identified." Chromium is a naturally existing metal and there could be a variety of sources, other than farm products and the Solite facility, e.g., combustion of natural gas, and coal that may be used in residential heating activities. Chromium is released as asbestos brake linings are worn down and therefore, farm and residential vehicles as well as trucks could be a source of low amounts of chromium."
      
      

      ATSDR Response:

      There are many potential sources of chromium in air. It is unlikely that enough residences use natural gas to heat their homes in this rural area to result in levels of chromium that exceed health based guidelines. Chromium is a by-product of burning coal. It is unlikely that residents use coal to heat their homes; this practice was popular in the 1800s and early 1900s. Most coal fire places were replaced with wood-burning fireplaces during early 1900s. Carolina Solite heats a significant amount of coal in its processes. ATSDR made no conclusions regarding the sources of chromium in air in this community. To clarify this point, ATSDR will add "because there are many potential sources of chromium in air, sources besides the Solite facility have not been identified" to the last sentence of the ambient air section on page 6, and delete the second half of the sentence.

   3. Comment: Page 17;
      
      

      "The last bullet on page 17 states, "Data regarding rates of brain cancer and cancer of the central nervous system in Stanly county are inconclusive." This statement appears to be inconsistent with statements earlier in the report. Tables on Page 11 clearly show that the rates for these cancers in Stanly county is not statistically different from the North Carolina general population nor the US general population. Furthermore, the study states on Page 12:

      "In this case, calculating the 95% confidence interval revealed that the difference between the state and national incidence rates and the Stanly county brain and CNS cancer rate is not significant. The standard mortality ratio includes 1, and suggests that other factors are contributing to the brain cancers diagnosed." (Emphasis added.)

      "In summary, a longer time frame of analysis is necessary in determining historical cancer trends in this county, and whether these trends are higher than expected rates for Stanly County residents. More importantly, it is difficult to determine whether or not Carolina Solite is contributing to the cancer rates in the county. There are no cancer studies focusing specifically on the residential area surrounding the Solite facility. Furthermore, current environmental data do not support the association between environmental emissions and cancer in residents of this community." (Emphasis added.)

      ATSDR Response:

      The data are inconclusive. The sample size of the cancers were too small for an adequate analysis of the cases reported. ATSDR could not identify evidence of a community-specific cancer review near the facility. There is no evidence that these were primary brain cancers (originating in the brain) and not secondary cancers (those which have spread from other locations in the body). In lieu of these limitations, data do not support an association between these cancers and the facility, nor do they qualify as significant enough to make any substantive conclusions regarding brain cancer in this community.

   4. Comment: Page 18;
      
      

   "The recommendations presented on Page 18 are not justified by the information presented in the report. The recommendations are addressed individually as follows:

   1. Air
      
      

      The ATSDR report concludes that neither the ambient air nor the personal breathing conditions for workers currently pose and adverse health threat. "No contaminants were detected at levels of health concern" (page 17). However, the ATSDR appears to concur with the installation of additional monitors (one near the facility and a "control" monitor), which suggests monitoring beyond the end of 2000. Clearly the report suggests the opposite. As the report concludes, there are no health threats posed by current ambient air concentrations and no evidence that Carolina Solite is the sole, or even major contributor, to the very low concentrations detected in the ambient air, thus, the need for additional monitoring is not apparent."

      ATSDR Response:

      Carolina Solite changed the type of fuel used in its processes in the Spring of 2000. ATSDR supports the NC DENR decision to continue monitoring the area to determine whether or not the change from HWDF to recycled oil for fuel would alter concentrations of metals in air. It is ATSDR's understanding that this monitoring was completed at the end of December 2000. ATSDR did not recommend sampling beyond the NC DENR sampling plan dates.

   2. Well Water
      
      

      "There are several questions regarding the recommendations associated with well water. The report concludes:

      "While there is historical evidence of surface and groundwater contamination of water on the property of Carolina Solite, current conditions do not indicate contamination of those water wells in 1999."

      Since there is not evidence of contamination currently, then logically there is not justification for continued monitoring. The ATSDR should be more clear and define 'elevated'."

      ATSDR Response:

      The reviewer misquoted the conclusion for water wells. The sentence is further clarified in the following manner:

      "While there is historical evidence of surface and groundwater contamination of water on the property of Carolina Solite, current conditions do not indicate contamination of residential water wells sampled in 1999."

      Accidental releases to local creeks and rivers can occur at any time. Current site conditions can change and result in future contamination. ATSDR did not recommend continued monitoring of residential water wells, but stated that if "sediment samples collected by EPA are elevated, NC DHHS and NC DENR should develop a public health action plan to monitor residential wells to ensure no leaching is occurring from the facility into groundwater". ATSDR has determined that this approach would be most protective of human health.

      ATSDR defined 'elevated' in the text. See paragraph 2 on page 8. Conclusions are short summaries of the information provided in the text. The health based guidelines are not presented again in the conclusions section of a public health assessment.

      "We believe that the streams and rivers that are planned for monitoring are not in any way connected to the groundwater from which the residents may be drawing their drinking water."

      ATSDR Response:

      Abermarle residents draw their water supply from the Rocky and Upper Pee Dee watersheds. Long Creek, which runs through the Solite property, is part of the Rocky watershed. It is at least possible that contamination of the creek may effect the health of the watershed as a whole and the aquifer which feeds local residential wells. In light of this, ATSDR supports the additional sediment sampling conducted by EPA in Spring of 2000.

      "We are unaware of any evidence that such elevations would be directly related to emissions or discharges from the Carolina Solite facility. For example, if elevated levels of arsenic are identified in the stream and rivers, how would ATSDR or the State of North Carolina distinguish between agricultural sources and Carolina Solite?"

      ATSDR Response:

      It is possible for Carolina Solite to directly impact local creeks, rivers, and streams and cause elevations of soil contaminants. As of July 2001, Carolina Solite continues to carry an active National Pollution Discharge Elimination System (NPDES) permit allowing it to release quarry dewatering wastewater to Long Branch Creek. Throughout most of the 1990s, the facility discharged processed wastewater in addition to the quarry wastewater to Long Branch Creek. In the past, the facility has been found in violation on numerous occasions regarding these discharges. On January 1990, the facility was issued a Notice of Violation for activities resulting in elevated levels of lead, cadmium, and copper in Lower Long Branch Creek, as well as the "violation of the Oil Pollution and Hazardous Substances Control Act of 1978 by allowing the spillage of petroleum products in the vehicle washing/maintenance area to discharge to the Upper Long Branch Creek via the sumps and associated piping [EPA RCRA Facility Assessment, 1992]."

      More evaluation would be necessary to determine the source of contamination if sediments samples are found to have high elevations of different constituents.

   3. Soil/sediment:
      
      

      "The ATSDR is calling for full characterization of soil on and off the Carolina Solite site. There is no justification for this characterization and expenditure of funds. What evidence exists to suggest that contamination of these soils and sediments currently exist and could pose a threat to the general population or employees of the facility? Because of the agricultural practices identified by ATSDR for the region, how would the source of any contamination be identified? Finally, what is the relevance of monitoring for priority pollutants in soils and sediments, if the concern is the influence of Carolina Solite emissions and discharges on the health of the surrounding population?"

   ATSDR Response: ATSDR supports the action taken by EPA on this issue. The sampling conducted in Spring 2000 is sufficient for screening area soils and sediment. These samples were collected to determine whether or not the facility may be impacting local soils and sediments. Elevated levels would require additional analysis to determine potential sources. The analysis of soil was necessary to determine if the deposition of air emissions may be affecting contaminant concentrations in soil, and sediment analysis is most often used to determine if effluent discharges are contaminating the local watershed.

   "The recommendations presented in this report appear to be offered as a means of enhancing scientific understanding about the presence of metals and priority pollutants in the general environment of Stanly County. While such enhanced understanding may be desirable, linking such research to the Carolina Solite facility leaves the very false impression that somehow the facility is a contributor to "imagined" environmental pollution. The ATSDR report has clearly indicated that there is no health threat posed to residents in Stanly County. It also clearly indicates that Carolina Solite has not historically nor in the near term presented adverse health threats as a result of its operation. Thus, there is no justification for these recommendations and no linkage with a public health action plan associated with operation of the Carolina Solite facility."

   ATSDR Response: ATSDR has identified environmental pollution released by Carolina Solite by examining the compliance records of the facility. Releases to local rivers, excessive fugitive releases to the air, and soil contamination near impoundment areas, the waste transfer area, the former wastewater treatment system, the treatment works pond, and the former pumphouse are examples of violations the facility has been cited for in the past. It is possible that contamination generated by this facility could negatively impact public health.

   5. Comment: Appendix C, Exposure Pathway Table:
      
      
      1. "Regarding the "surface soil contamination pathway," the soil sampling being recommended off the Solite site will not provide any information about an association between the operation of the Carolina Solite facility and constituents detected in the soil and sediment. This lack of association is supported by the ATSDR's evaluation that many of the constituents occur naturally and are present in agricultural materials commonly used in the region."
         
         

         ATSDR Response:

         Surface soil testing is often used to determine whether or not facility emissions are impacting local residential soils. ATSDR is of the opinion, as is EPA and NC DENR, that this data will help determine whether facility emissions are depositing and accumulating in residential soils.

      2. "Regarding the "groundwater pathway", if the ground water is currently safe, what justification is there to expect future problems? Any future problems could be equally associated with agricultural practices as with the operation of the Carolina Solite facility."
         
         

      ATSDR Response:

      As long as Carolina Solite maintains a NPDES permit and discharges into local rivers, there is a possibility that it could impact local water quality.

   6. Comment: Appendix G, Health Implications
      
      

      Additional information would aid the public understanding of the diseases of concern. For example:

      1. Alzheimer's Disease - This disease is becoming increasingly more common,particularly as our society ages. Nearly 10% of all persons over the age of 70 have significant memory loss that is attributed to Alzheimer's Disease (Bird 1997). The most important risk factors are old age and a family history of the disease. It would provide a greater service, if the report presented the risk factors in categories such as well-known, probable, and controversial. For example, as indicated in the website-http://www.alzheimers.com:
         
         
         1. Well-established risk factors include increasing age, family history or genetic factors, and being female.
            
            
         2. Probable risk factors include presence of apolopoprotein E, infrequent use of nonsteroidal anti-inflammation drugs, nor or brief use of estrogen replacement therapy, deficiencies in antioxidant nutrients, head injuries with loss of consciousness, heart disease, stroke and high blood pressure, and a family history of Down's syndrome.
            
            
         3. Controversial risk factors include low education level, poor linguistic and writing ability, history of seizures, exposure to large amounts of zinc, and exposure to aluminum.
            

         The ATSDR reference to exposure to electromagnetic fields (EMFs) is a questionable risk factor and if supported at all in the scientific/medical literature would be categorized as controversial at best. The ATSDR should also review the latest studies conducted by the Institute of Electrical and Electronic Engineers (IEEE) regarding EMF exposure.

         Bird, T.D. 1997. "Chapter 367. Alzheimer's disease and other primary dimentias." In Harrison's Principles of Internal Medicine, eds. Fauci et. Al. New York, NY: McGraw Hill, pp. 2348-2351.

         ATSDR Response: The format of this section is a matter or preference. The author of this assessment found that all the information above was discussed in the existing section. The existing section mentions that exposure to EMFs has been a proposed risk factor, but that it is not well-established.

      2. Asthma- The ATSDR appears to have ignored the most recent scientific finding that the quality of indoor air is believed to be a major factor in development and exacerbation of asthma. Some studies are suggestive that indoor air quality plays a greater role than outdoor air quality, see for example, the following references.
         
         

   Bielory, L. and Deener, A. 1998. "Seasonal variation in the effects of major indoor and outdoor environmental variables on asthma." J Asthma 35:7-48.

   D'Amato, G. Liccardi, G., and D'Amato, M. 1994. "Environment and development of respiratory allergy. II. Indoors." Monaldi Arch Chest Dis 49:412-420.

   Jones, A.P. 1998. "Asthma and domestic air quality." Soc Sci Med 47:755-764.

   Kimer, I. 1998. "Allergy, asthma, and the environment: an introduction." Toxicol Lett 102-3:301-306.

   National Research Council. 2000. Clearing the Air: asthma and indoor air exposures. National Academy of Science, Institute of Medicine, Committee on the Assessment of Asthma and Indoor Air, Division of Health Promotion and Disease Prevention. Washington, D.C: National Academy Press.

   ATSDR Response:

   See page G-3, paragraph 2. It reads "There are a number of factors that are believed to contribute to developing asthma, many of which are from indoor exposures." There is a list of factors following this statement, including animal dander, molds, fungi, dust mites, cockroaches, and indoor cigarette smoking, all of which are well-established indoor exposures.

   See page G-4, second sentence. It reads "There are quite a number of factors that can contribute to the onset of asthma, many of which are related to the conditions a person is exposed to in his home." ATSDR adequately noted these risk factors. The idea that indoor air quality plays a greater role in the development and exacerbation of asthma is not a new finding. ATSDR is aware of current issues regarding asthma.

   6. Comment: Appendix H
      
      

      "The discussion of cancer risk presented in this appendix would be improved if placed in a proper context. First, it should be pointed out to the reader that a cancer risk represents only a probability that cancer may develop in an individual with the specific exposure assumptions used in the assessment."

   ATSDR Response: See paragraph 2 where the meaning of risk is explored and paragraph 3 where ATSDR assumptions are explained in detail.

   "Second, it should be pointed out that even if a risk appears unacceptable (acceptable risk in the RCRA combustion of hazardous waste programs is 1 in 100,000 or 1 x10 ^-5), it does not mean that cancer will result."

   ATSDR Response: ATSDR has risk categories, and the average concentrations of arsenic, cadmium, and chromium in this community were calculated to result in approximately 1 in 100,000 cancer cases. By ATSDR definition, this is no apparent increase in cancer risk. The concept that risk does not equal actual cases is explained in paragraph 2.

   "Third, the discussion of risk estimates presented on page H-4 would be improved if it included a brief discussion about the background of cancer risk (i.e, risk unrelated to environmental factors). The American Cancer Society has estimated a background risk for the U.S. population as 0.33. The risks in the table on H-4 represent only an incremental increase over this background risk (i.e., 0.330000 + 0.000005 for the risk associated with the average concentration of arsenic)."

   ATSDR Response: The point is well taken. However, for the sake of simplicity, "no apparent increase in cancer risk" will suffice.

   "The discussions would also be improved if the report presented the conservative assumptions as noted on page H-2 along with more site-specific assumptions and an associated cancer risk. For example, the report states that an individual residence time for Stanly County is only 16 years, not the 70 years used in the ATSDR calculation. The exposure frequency is likely less than 365 days of continuous exposure as a family may be away from the immediate area for work, or attendance of school, or during vacation periods. EPA's default duration is 350 days per year. By presenting both a conservative and more site-specific estimate of risk, the readers can reach their own conclusions about the probability of cancer associated with ambient levels of arsenic in air."

   ATSDR Response: It is ATSDR's opinion that if the most conservative estimate would not result in an increase of cancer risk, there is no need to recalculate with more site specific assumptions.

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   This page last updated on October 10, 2001
   
   Contact: Joanne Cox / vzc6@cdc.gov
   
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