PUBLIC HEALTH ASSESSMENT
TAYLOR LUMBER AND TREATING, INCORPORATED
SHERIDAN, YAMHILL COUNTY, OREGON
Taylor Lumber and Treating (TLT) was proposed for the National Priorities List (NPL) on December 1, 2000 and listed on June 14, 2001. In this public health assessment the Superfund Health Assessment and Education (SHINE) program of the Oregon Department of Human Services (ODHS) evaluates the public health importance of the site as mandated by Congress.1 SHINE has reviewed available environmental data and community health concerns to determine whether adverse health effects are possible. In addition, this public health assessment recommends actions to prevent, reduce, or further identify the possibility for site-related adverse health effects.
Based on the environmental sampling conducted at the former Taylor Lumber and Treating facility, SHINE considers this site to be a no apparent public health hazard.
This site description comes in part from the Taylor Lumber and Treating Site Integrated Assessment Report (July 2000) and the Taylor Lumber and Treating Community Involvement Plan (January 2002) [1,2]. The TLT NPL site is located on the western edge of Sheridan, Yamhill County, Oregon (Figure 1), in the northeast quarter of Section 33 and the northwest quarter of Section 34, Township 5 South, Range 6 West. The coordinates of the site are approximately 45° 06' 00.0" north latitude and 123° 25' 30.0" west longitude [1].
The site covers about 234 acres and includes a maintenance shop, a sawmill, a tank farm with 13 aboveground storage tanks, and a laboratory [2]. Half of the site is agricultural land, and the other half is evenly split between wood treating and sawmill and planning facilities [1]. On the north, west, and south the surrounding area is agricultural land; the east side is mostly commercial/industrial properties and some residences [1,2]. The site is located just north of the Yamhill River and east of Rock Creek. TLT lies along State Highway 18B, a heavily used business loop.
Figure 1. Taylor Lumber NPL Site Area
The sawmill operated from 1946-2001 [1,2]. Its operations included the peeling, milling, planing, and chipping of raw wood to produce lumber products. The ends of the finished lumber products are painted to prevent moisture loss. Wood chips and bark are burned in the boiler, which generates steam for the facility. From the 1960s through the 1980s waste and debris from site operations were deposited in an area southeast of the planing mill.
The wood-treating facility (west facility) operated from autumn 1966-2000 [1,2]. The purpose of the wood treating was to condition and pressure-treat wood products with preservatives to prolong their useful life. Wood products treated at the facility included lumber, poles, pilings, posts, railroad ties, and plywood. Wood-preserving chemicals, which historically have been used at this facility, include petroleum-based creosote and pentachlorophenol (PCP) solutions. From 1982 to 1996, Chemonite, a 3% water-based solution containing arsenic acid, copper salts, zinc, and ammonia, also was used as a wood-preserving chemical at the site. The wood-treating chemicals were stored in aboveground storage tanks (ASTs) located in two separate tank farms.
Numerous violations have occurred at this site over the past decade [1]. In
February 1999, 3500 gallons of 5% P-9 oil spilled from the tank farm and collected
in drainage ditches. During September 1999, approximately 27,500 gallons of
reclaimed creosote and wastewater 
were released when their tanks topped over,
with some contaminated wastewater spilling into nearby ditches. In June and
August 1999, the EPA conducted an Integrated Assessment (IA) of the Taylor Lumber
and Treating facility [1]. Phase I of the IA included surface and subsurface
soil sampling, groundwater sampling, surface water, and river creek sediment
sampling. Phase II of the IA consisted of an air-sampling event. Results of
the IA documented the presence of several on-site sources of hazardous substances,
including volatile organic compounds (VOCs), semi-volatile organic compounds
(SVOCs), pentachlorophenol (PCP), metals, and dioxins and furans. Further, many
of these hazardous substances were documented to have migrated to surface water,
soil, and air targets. Air contamination is documented up to 1 mile from the
site.
The EPA has conducted several remedial activities to abate some of the contamination. Abatement activities include the installation of a slurry wall to prevent the migration of the majority of groundwater pollutants within the West Facility of TLT. Also, several thousand tons of contaminated soil were removed and placed in storage cells in the western edge of the facility. The contaminated soil is covered with tarps and surrounded by an unsecured fence. To diminish contact with soil contaminants, asphalt was placed over sections of TLT.
Pacific Wood Preserving Companies (PWP), a large volume treater of low-environmental-impact wood, recently purchased the West Facility of TLT and began operations in approximately June 2002. PWP uses borate and copper-based products to treat their wood. The company is operating an extraction system that prevents groundwater pollution from reaching the South Yamhill River.
Currently, several physical hazards exist on and around the West Facility of TLT. A large kiln oven and an abandoned control facility with exposed insulation are present between TLT property and a residence to the west of the facility. On site, numerous piles of debris, scrap metal and loose insulation exist, especially around the pole-drying area. New construction and refinishing of existing structures is underway, which could reduce the amount of debris.
The demographics of the Taylor Lumber area are displayed on Figure 2. The area near TLT is sparsely populated. There are over 450 members of the Confederated Tribes of the Grande Ronde within 5 miles of the site, an area that includes Yamhill and Polk Counties.
The area around the former TLT site has industrial, commercial, agricultural and residential uses. The western boundaries of the City of Sheridan include the eastern portion of TLT. A Head Start facility has been approved for development approximately 500 feet southeast of the TLT facility, along Highway 18B. The Oregon Department of Environmental Quality (DEQ) has conducted an in-depth investigation of contamination on the Head Start property and concluded that no probable threat to human health exists at the site. Included in the construction of Head Start facility was the removal of the top 6 inches of soil and replacement with clean fill–a recommendation that was supported by SHINE. Farther east is an assisted living facility and numerous commercial and residential buildings.
To the north of the TLT facility, across from railroad tracks, is a hay field. Private residences line Rock Creek Road and Highway 18B, including homes adjacent to ditches and sediment receiving storm water runoff. An additional residence lies along TLT's western edge.
TLT has two main sections: the West Facility and East Facility. The West Facility, under the new ownership of Pacific Wood Preserving Companies, has begun operation. The East Facility is owned by "Dee" Industrial and by Esquire Investments Inc., which manufactures outdoor cedar furniture.
Our discussions with staff of the City of Sheridan indicate that residents inside the city limits obtain their drinking water from the Sheridan drinking water system. This system obtains most of its water from groundwater sources. During peak demand periods in summer, water from the Yamhill River is often obtained downstream of TLT. The residents immediately west of TLT currently get their water from a private well.
Figure 2. Basic Demographics Map
Several environmental investigations have been conducted within TLT and in the vicinity. The investigations have included sampling soil, sediment, air, water and groundwater. The majority of the data used are derived from two comprehensive sampling efforts. After the February 1999 spill, the EPA Superfund Technical Assessment and Response Team (START) conducted an Integrated Assessment (IA). The IA assessed the contamination at TLT West and East Facilities [3]. Data from a 2000 Removal Action (RA) report was reviewed in this assessment [4]. The RA data was collected to address imminent and substantial health concerns to the public. Recent groundwater data, collected in 2002–after the installation of a soil-bentonite barrier wall in the West Facility–is included. Residential soil samples and ditch samples at the intersection of Highway 18B and Rock Creek Road collected in July and August 2002 were analyzed as well. Several remedial activities have occurred at TLT to address the most imminent health hazards. Some of the contamination levels reported in this document were measured before removal and remediation actions occurred. The on-site surface soil samples were collected from 0-2 feet below ground surface, while the off-site surface soil samples were collected from 0-1 feet below ground surface [1].
ATSDR and ODHS visited the Taylor Lumber area on September 10-11, 2001 to better understand the physical setting of the site and its relationship to the people living and working nearby.2 The first meeting occurred with members of the Confederated Tribes of the Grand Ronde. We also met with residents of Sheridan and local, state, and federal officials to learn more about the site and the health concerns of the community.
On June 12, 2002, SHINE and ATSDR staff visited the West Facility of Taylor Lumber to assess further the physical and geographical setting of the site.3 During the tour, SHINE visited with the City Manager and Director of the Municipal Water Supply to learn about community concerns and drinking water distribution and monitoring.
The process by which ATSDR evaluates the possible health impact of contaminants is summarized here and described in more detail in Appendix A. Briefly, ATSDR uses comparison values (CVs) to determine which chemicals require further examination. CVs are health-based thresholds below which no known or anticipated adverse human health effects occur. Exceeding a CV does not mean that health effects will occur–just that more evaluation is needed. Further information about CVs is presented in Appendix B.
Further evaluation focuses on identifying which chemicals and exposure situations could be a health hazard. The first step is the calculation of child and adult exposure doses as described in Appendix B. These are then compared to an appropriate health guideline for a chemical. Any exposure situation resulting in an exposure dose lower than the appropriate health guideline is eliminated from further evaluation.
The next step is the revision of the exposure dose to better match probable rather than worst-case exposure scenarios. Lastly, these revised exposure doses are compared to known toxicological health effects levels identified in ATSDR toxicological profiles. If the chemical of concern is a carcinogen, the cancer risk is recalculated using the revised exposure dose. These comparisons are the basis for stating whether the exposure is a health hazard.
Toxic equivalency quotients (TEQs) for dioxins, furans and polycyclic aromatic hydrocarbons (PAHs), were calculated using the Van den Berg method [5].
Taylor Lumber Exposure Pathways and Contaminants of Concern
Based on the available data, the most probable means of exposure to site contaminants are through incidental ingestion of contaminated soil and exposure to ditch sediment. Completed, potential and eliminated exposure pathways will be described in the following sections.
Discussion of specific human exposure pathways in this section does not imply that adverse health effects will develop. ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if that pathway cannot be eliminated. Five factors are required to qualify a pathway as completed: 1) a source of contamination, 2) transportation through an environmental medium, 3) a point of exposure, 4) a route of human exposure and 5) a receptor population. Potential pathways require that at least one of these factors is missing, but could be present. An exposure pathway can be eliminated if at least one of the five factors will always be absent.
The focus of this public health assessment is current exposure. Past air exposures are discussed in Appendix C on page 27.
Current and future exposures to site contaminants are likely to occur from contact with on-site surface soil. Incidental soil ingestion and skin contact with contaminants are routes of exposure for workers and visitors to the site. That said, however, the opportunity for contact with contaminants on site by children and adults trespassing on the site is limited by the presence of a fence around TLT, observed during our two site visits. Therefore, this exposure pathway is most relevant to TLT workers.
During the initial screening, sample results were compared to the appropriate comparison values (CVs)–health-based thresholds below which no known or anticipated adverse health effects occur. If a contaminant exceeds a CV, it was evaluated further. As shown in Table 1, several contaminants in Taylor Lumber soil exceeded their corresponding CV at least once. Table 1 describes the range of contaminants in the former West Facility of Taylor Lumber. The vast majority of contamination can be found on the West Facility compared with levels of pollution at the East Facility. This is a result of activities conducted by Taylor Lumber at the West Facility, including the two large spills that occurred in 1999.
Table 1. On-Site Soil Contaminants Above Comparison Values
| Contaminants | Range in Soil (ppm*) | Samples > DL†/Total | Samples > CV‡ | CV in ppm | CV Source§ |
| Dioxin/Furan TEQs¶ | 0.001-0.044 | 44/44 | 44/44 | 0.001 | ATSDR PHA** |
| Arsenic | ND-778 | 43/44 | 15/44†† | 0.5/20‡‡ | CREG§§/EMEG¶¶ |
| Chromium | 14-156 | 44/44 | 4/44 | 64 | PRG*** |
| Manganese | 200-5660 | 44/44 | 1/44 | 3000 | RMEG††† |
| Pentachlorophenol | ND-960 | 27/66 | 11/66 | 3/50 | PRG/EMEG |
| PAH TEQs¶ | 0-3.81 | 29/66 | None | ||
| *ppm = parts
per million of chemical in soil. ppm = mg (milligram) per kg (kilogram of
soil). †DL = Detection Limit ‡CV = Comparison Value §These comparison values are described in Appendix A ¶ TEQ = toxicity equivalency quotient; based on the relative potency to 2,3,7,8-TCDD for dioxins/furans and benzo(a)pyrene for polyaromatic hydrocarbons **ATSDR Public Health Advisory (1983) ††The first number is the number of samples above the CREG and the second is the number above the EMEG ‡‡The first comparison value is the CREG and second comparison value is the EMEG §§CREG = cancer risk evaluation guide ¶¶ EMEG = environmental media evaluation guide ***PRG = preliminary remediation goal †††RMEG = remedial media evaluation guide |
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The next step in the exposure pathway evaluation is to estimate doses, or amounts of the chemicals to which adults and children would be exposed, and to compare these doses with health guidelines. This procedure is detailed in Appendix B. The health guidelines are doses below which no adverse health effects are likely to occur. Exposure situations resulting in doses lower than the health guideline are dropped from further consideration.
The estimated exposure doses for soil contaminants of concern are presented in Table 2. Exposure doses were calculated based on a year-round exposure scenario and 100% bioavailability (except a default of 80% bioavailability for arsenic was used) for soil ingestion. It was assumed that a 10-year-old would be the youngest child that could regularly access the site, so a body weight of 36 kg was used. The average soil concentration was used to derive a chronic exposure, as it is highly unlikely that someone would contact only one location over several years.
Table 2. Estimated Exposure Doses and Cancer Risk for On-Site Soil Compared to Health Guidelines for Ingestion*
| Contaminant | Concentration (ppm)† | Estimated Exposure Dose (mg/kg/day)‡ | Health Guideline (mg/kg/day) | Source of Guideline | Cancer Risk | |
| Adult | Child | |||||
| Dioxin/Furan TEQs§ | 0.0016 | 2E-09 | 4E-9 | 1E-09 | Chronic Oral MRL¶ | 6 in 10000** |
| PAH TEQs§ | 0.43 | 6.70E-07 | 1.2E-06 | none | 1 in 100000 | |
| *An explanation
of how exposure doses and cancer risk were calculated can be found in Appendix
B. No health guidelines are available for the PAHs. † ppm = parts per million ‡ mg/kg/day = milligrams of chemical per kilogram of body weight per day §TEQ = toxicity equivalency quotient; based on the relative potency to 2,3,7,8-TCDD for dioxins/furans and benzo(a)pyrene for polyaromatic hydrocarbons ¶ MRL = ATSDR's minimal risk level **Maximum additional lifetime risk of cancer per 10,000 individuals |
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The exposure doses calculated above likely overestimate actual exposures that occur from soil. It should be noted that several of the sample sites have been capped with asphalt or removed from the Taylor Lumber West Facility. Therefore, this scenario is highly protective of public health. Exposure during the rainy season could alter exposure. Outdoor activity and suspension of contaminated dust particles could be diminished, while skin adherence of contaminated mud could increase.
Movement of TLT contaminants to soil off site could have occurred through surface draining from the site, flood events and the blowing of contaminated soil off site. Off-site soil exposure to nearby-residents, especially children, can occur through ingesting soil and through skin contact with pollutants. Children who tend to play in residential and non-residential dirt have elevated hand-to-mouth activity, thus ingesting more soil as compared to adults. Playground equipment was evident in residences along Rock Creek Road and Highway 18B, adjacent to the site. Gardens were also noted, as was one residence that had treated wood and 55-gallon drums in the front yard.
Fourteen samples were collected from driplines in residences near TLT in previous sampling efforts. These off-site samples were collected from 0-1 foot below the surface. To properly evaluate the human health risk, shallower samples (0-3 or 0-6 inches) are preferred. Twelve additional soil samples were taken in July and August 2002 and collected from 0-6 inches. These samples were taken from residences located close to the Taylor Lumber facility.
The main contaminants of concern are listed in Table 3. For this off-site area, we assumed that 1-2 year old children could regularly contact off-site soil, so a 10 kg body weight was used.
Table 3. Off-Site Soil Contaminants Above Comparison Values
| Range in soil (ppm*) | samples > DL† | samples > CV‡ | CV in ppm | CV Source§ | |
| Arsenic | 3.4-14 | 26/26 | 26/0¶ | 0.5/20** | CREG††/ EMEG‡‡ |
| Iron | 22700-68700 | 26/26 | 25/26 | 23000 | PRG§§ |
| Lead | 9.1-2800 | 26/26 | 2/26 | 400 | PRG |
| PAH TEQs¶¶ | ND-1.1 | 3/14 | none | ||
| Chromium | 16-78 | 24/24 | 19/26 | 30 | PRG |
| *ppm = parts
per million of chemical in soil. ppm = mg (milligram) per kg (kilogram of
soil). †DL = Detection Limit ‡CV = Comparison Value §These comparison values are described in Appendix A. ¶The first number is the number of samples above the CREG and the second is the number above the EMEG. **The first comparison value is the CREG and second comparison value is the EMEG ††CREG = cancer risk evaluation guide ‡‡EMEG = environmental media evaluation guide §§PRG = preliminary remediation goal ¶¶TEQ = toxicity equivalency quotient; based on the relative potency to benzo(a)pyrene for polyaromatic hydrocarbons |
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Toxicological Evaluation for On-site and Off-site Soils
Childhood exposure to contaminants in soils is especially problematic, given a child's lower body weight and accelerated hand-to-mouth activity, both of which lead to a higher potential for exposure. These factors increase the chance of children–if continually exposed to these sites throughout their lifetime–developing long-term effects. Still, because on-site access to Taylor Lumber is restricted for minors, the probability of developing health effects is diminished.
Dioxins and furans consist of a family of approximately 210 different compounds with different levels of chlorination. The dioxins and furans could cause varying health effects. The most studied and toxic member of the dioxin family is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Dioxins and furans occur at very low levels in the environment and can be found in food, water, air and cigarette smoke.
One of the most characteristic effects of exposure to TCDD is a severe skin disease known as chloracne. This condition consists of acne-like lesions, usually found on the face and upper neck. Other skin effects include red rashes, discoloration, and excessive body hair. In addition, liver damage and impaired immune function could result in people exposed to elevated levels of dioxins. Very few studies have examined how dioxins and furans affect children's health, but children do appear to be more sensitive compared to adults [6].
It is unlikely that non-cancer health effects would occur from exposure to dioxins and furans at Taylor Lumber. This is because both on-site and off-site soil exposure doses for adults and children are lower than the no observed adverse effects level (NOAEL) reported for rhesus monkeys [7]. There are no health guidelines based on human exposure to dioxins and furans
Long-term exposure to dioxins and furans could increase the likelihood of developing cancer. Based on the exposure doses calculated in Table 4, a theoretical increased risk of cancer exists in people exposed to soil at or near the Taylor Lumber facility over long periods of time. Studies in rats and mice exposed to TCDD resulted in thyroid and liver cancer [8]. Nevertheless, it should be noted that the cancer potency number used to derive these numbers is highly controversial. Some scientists suggest that the cancer risks posed by low levels of dioxin exposure are overstated [9].
Table 4. Estimated Exposure Doses and Cancer Risk for Off-Site Soil Compared to Health Guidelines for Ingestion*
| Contaminant | Concentration (ppm)† | Estimated Exposure Dose (mg/kg/day)‡ | Health Guideline (mg/kg/day) | Source of Guideline | Cancer Risk | |
| Adult | Child | |||||
| Iron | 48941 | 0.07 | 0.98 | 0.3 | pRFD§ | N/A¶ |
| PAH TEQs** | 0.2 | 2.90E-07 | 4.00E-06 | None | 3 in 100000†† | |
| *An explanation
of how exposure doses and cancer risk were calculated can be found in Appendix
B. No health guidelines are available for the PAHs. † ppm = parts per million ‡ mg/kg/day = milligrams of chemical per kilogram of body weight per day § provisional RfD = Reference Dose ¶ Not applicable; substance is not classified as a carcinogen ** TEQ = toxicity equivalency quotient; based on the relative potency to benzo(a)pyrene for polycyclic aromatic hydrocarbons †† Maximum additional lifetime risk of cancer per 100,000 individuals |
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Polycyclic Aromatic Hydrocarbons:
Polycyclic aromatic hydrocarbons (PAHs) are structurally related compounds with similar properties. PAHs are formed during the incomplete combustion of carbon containing materials. Workers and visitors to Taylor Lumber and nearby residents might have been and might continue to be exposed to PAHs through inhalation, skin contact and incidental ingestion. The use of creosote and other wood preservatives at Taylor Lumber contributed to the elevated levels of PAHs found on site. Animal studies have shown that PAHs can harm liver and blood at high doses. The estimated exposure dose of PAHs in children ingesting soils in the vicinity of Taylor Lumber is 0.000004 mg/kg/day (parts per million per kg per day). This dose is far less than the concentrations that produced adverse effects in animal testing [10]. Therefore, it is unlikely that any health effects would result as a result of incidental ingestion of contaminated soils.
Estimated childhood exposure to iron from soil is higher than the health guideline of 0.3 mg/kg/day. This does not imply that health effects will occur. Long-term exposure to elevated iron, however, at concentrations much greater than 0.3 mg/kg/day, could result in accumulated iron in the liver. One study demonstrated that severe effects would not be anticipated at doses below 30 mg/kg/day [11].
South Yamhill River and Ditch Sediment Pathway:
Sediment samples were collected from ditches surrounding the Taylor Lumber facility. The focus of this exposure pathway analysis is on a series of sampling sites near the junction between Rock Creek Road and Highway 18B, at the southeast corner of the West Facility. Elevated levels of arsenic, dioxin and PAHs were detected in the ditch and riverbank sediments around this area. Several residences are located near the junction of Rock Creek Road and Highway 18B, as well as near the proposed Head Start facility.
Children playing in ditches and recreational users of the South Yamhill River would most likely be exposed to river and ditch sediment. The exposure scenario for this area is outlined in Appendix B. Table 5 presents the contaminants that were detected above comparison values.
Table 5. Ditch Sediment Contaminants Above Soil Comparison Values
| Contaminants | Range in Soil (ppm*) | Samples > DL†/Total | Samples > CV‡ | CV in ppm | CV Source§ |
| Arsenic | 4.2-445 | 27/27 | 27/27 | 0.5/20¶ | EMEG/CREG |
| Dioxin/furan TEQ** | 3.5E-6 - 0.003 | 8/9 | 2/9 | 0.001 | ATSDR PHA†† |
| PAH TEQ** | 0.07-2.2 | 21/24 | none | ||
| Benzo(a)anthracene | ND-0.7 | 16/24 | 1/24 | 0.6 | R9 PRG‡‡ |
| Benzo(a)pyrene | ND-1.8 | 22/25 | 21/25 | 0.06 | R9 PRG |
| Benzo(b)fluoranthene | ND-2.4 | 19/25 | 5/25 | 0.62 | R9 PRG |
| Indeno(1,2,3-cd)pyrene | ND-1.8 | 17/26 | 4/26 | 0.62 | R9 PRG |
| Iron | 31800-92900 | 25/25 | 25/25 | 23000 | R9 PRG |
| *ppm = parts
per million of chemical in soil. ppm = mg (milligram) per kg (kilogram of
soil). †DL = Detection Limit ‡CV = Comparison Value §These comparison values are described in Appendix A. ¶The first number is the CREG and the second is the EMEG **TEQ = toxicity equivalency quotient; based on the relative potency to 2,3,7,8-TCDD for dioxins/furans and benzo(a)pyrene for polyaromatic hydrocarbons ††ATSDR Public Health Assessment (1983) ‡‡R9 PRG = EPA Region 9 Preliminary Remediation Goal |
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No contaminants with known health guidelines were detected at levels that would be anticipated to cause adverse health effects. For ditch sediment, childhood exposure was assessed as a combination of dermal contact and incidental soil ingestion from playing in the ditches. The assessment of this area assumed a child would play in the ditch sediment at the intersection of Rock Creek Road and Highway 18B 1 day per week, over 6 years. If children play in the area more frequently, their exposure would increase accordingly. This area has some the highest levels of arsenic, PAHs and dioxins off site of the Taylor Lumber facility. Although no adverse health effects are anticipated, SHINE recommends restriction of this site by extending the fence line to include the ditches, or removal of the sediment in the ditches and replacing it with clean fill.
Based on limited testing of residential wells near the Taylor Lumber facility, groundwater is considered a potential exposure pathway. That said, groundwater samples taken at a residence immediately west of the Taylor Lumber facility did not detect contaminants at levels anticipated to result in adverse health effects.
Air is considered a potential exposure pathway–the new wood preserving process used by Pacific Wood Preserving Companies employs copper naphthenate and borate based products with uncertain air releases.
In fact, the wood preserving process TLT used previously resulted in numerous air releases [1]. Air samples were collected from three on-site locations and four sites of varying distance from the West Facility. Elevated levels of arsenic and chromium were detected on multiple days. Pentachlorophenol, PAHs, and naphthalene compounds were detected above comparison values as well. Nearby residents and Taylor Lumber workers were likely exposed to these contaminants to some degree. But none of the contaminants detected above comparison values exceeded health guidelines. Therefore, adverse health effects would not be expected. A comparison table and toxicological evaluation are presented in Appendix C.
To address potential future concerns for 1) the proposed Head Start facility, 2) the assisted living facility and 3) nearby residents, air monitoring should continue near Taylor Lumber. The new copper and borate-based products that will be used could affect susceptible individuals.
Elevated levels of dioxins, arsenic, pentachlorophenol and polycyclic aromatic hydrocarbons are found within the Taylor Lumber West Facility. In October 2000, a slurry wall containing 5% bentonite was constructed to prevent the migration of the majority of groundwater contamination at the site. No groundwater wells are planned for this area. If the slurry wall functions properly, off-site migration of contaminants should not occur. Therefore, exposure via this pathway is unlikely.
Evaluation of Health Outcome Data
The Superfund law requires that health outcome (i.e., mortality and morbidity) data (HOD) be considered in a public health assessment [12]. This is done using specific guidance in ATSDR's Public Health Assessment Guidance Manual and a 1996 revision to that guidance [13,14]. The main requirements for evaluating HOD are presence of a completed human exposure pathway, great enough contaminant levels to result in measurable health effects, sufficient persons in the completed pathway for health effects to be measured, and a health outcome database in which disease rates for population of concern can be identified [14].
This site does not meet the requirements for including an evaluation of HOD in this public health assessment. Although completed human exposure pathways exist at this site, the exposed population is not large enough to permit meaningful measurement of possible site-related health effects as identified in existing HOD.
SHINE considers this site to be a no apparent public health hazard based on the lack of exposure to contamination found at the TLT site at levels which might result in adverse health effects.
SHINE and ATSDR recognize that infants and children could be more vulnerable to exposures than are adults in communities faced with contamination of their air, water, soil, or food. This vulnerability is a result of the following factors:
Because children depend on adults for risk identification and management decisions, SHINE and ATSDR are committed to evaluating their special interests at the Taylor Lumber site.
The major exposure route for children living near Taylor Lumber is ingestion of contaminated soils. Please refer to the appropriate section for discussion of the health effects that are possible for children.
On September 10, 2001, staff from ODHS, ODEQ, EPA and ATSDR met with the members of the Grand Ronde. Tribal members expressed concerns about elevated cancer rates and the potential for tribal members living in Sheridan to be exposed to TLT contaminants in the municipal drinking water. On September 11, 2001, ATSDR, ODHS, and ODEQ met with Sheridan residents. The residents voiced concerns about groundwater contamination, exposure of TLT workers during facility operations, exposure of residents to contaminants blowing off site, allergic reactions to these contaminants, and water supply issues. An additional public availability meeting was held on May 20, 2003 to address any concerns about the TLT health assessment and site. SHINE is working with the Grand Ronde to investigate their concerns about elevated cancer rates among tribal members. Still, because most tribal members live some distance from TLT, the opportunity for exposure of most tribal members to TLT contaminants ranges from limited to nonexistent.
To respond the concerns expressed about the municipal water supply, SHINE reviewed data for the Sheridan municipal drinking water supply. No contaminants were detected above the standards of the Safe Drinking Water Act. In addition, our discussions with City of Sheridan staff indicate that the amount of water used from the Yamhill River was small and that use of the Yamhill began after most of the TLT releases into the Yamhill occurred.
SHINE will work with EPA to inform the public on issues related to the Superfund process for the Taylor Lumber site.
The Public Health Action Plan for the Taylor Lumber and Treating NPL Site contains a description of actions to be taken by SHINE at the site after the completion of this public health assessment. The purpose of the Public Health Action Plan is to ensure that this public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and to prevent adverse human health effects resulting from exposure to hazardous substances in the environment. Included is a commitment on the part of SHINE to follow up on this plan to ensure that it is implemented. The public health action to be implemented is as follows:
SHINE will reevaluate and expand the Public Health Action Plan when needed. New environmental, toxicological, or health outcome data, or the results of implementing the above proposed action plan could signal the need for additional actions at this site.
The public comment release of this public health assessment (PHA) was available
for public review at the following repositories in Oregon: Sheridan Public Library,
142 N.W. Yamhill St., Sheridan; McMinnville Public Library, 225 N.W. Adams St.,
McMinnville; and the Grand Ronde Tribal Community Clinic, 9515 Grand Ronde Road,
Grand Ronde. The document was released on May 1, 2003 and was available for public comment
until July 17, 2003. The document was also available on the web at http://www.dhs.state.or.us/publichealth/superfund/docs/tlpha.pdf
The public comment period was announced in local newspapers. The PHA was sent to EPA and its contractor - CH2MHILL, ODEQ; the City of Sheridan, Yamhill County Health Department, Yamhill County Headstart, Confederated Tribes of the Grand Ronde, Pacific Wood Preserving of Oregon, and one private citizen. No comments were received.
Authors of Report
Dave Stone, Ph.D.
Toxicologist
Oregon Department of Human Services- Superfund Health Investigation and Education
Program
John R. Crellin, Ph.D.
Senior Environmental Epidemiologist
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
ATSDR Regional Representative
Richard Robinson
Regional Representative
ATSDR Region 10
Regional Operations
Oregon Department of Human Services - Superfund Health Investigation and Education Program
Janice Davin Panichello, M.P.A.
Program Coordinator
Amanda M. Guay, M.P.H.
Health Educator
The Taylor Lumber Public Health Assessment was prepared by the Oregon Department of Human Services under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with the approved methodology and procedures that existed when this document was begun.
John R. Crellin
Technical Project Officer, SSAB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health consultation and concurs with the findings.
Roberta Erlwein
Chief, State Program Section, DHAC, ATSDR
APPENDIX A: EXPLANATION OF EVALUATION PROCESS
In evaluating these data, ATSDR used comparison values (CVs) to determine which chemicals to examine more closely. CVs are the contaminant concentrations found in a specific media such as soil or water that are used to select contaminants for further evaluation. CVs incorporate assumptions of daily exposure to the chemical and a standard amount of air, water, and soil that someone could inhale or ingest each day.
As health-based thresholds, CVs are set at a concentration below which no known or anticipated adverse human health effects are expected to occur. Different CVs are developed for cancer and non-cancer health effects. Non-cancer levels are based on valid toxicological studies for a chemical, with appropriate safety factors included. They are also based on the assumption that small children (22 pounds) and adults are exposed every day. Cancer levels are the media concentrations at which there could be a one in a million excess cancer risk for an adult eating contaminated soil or drinking contaminated water every day for 70 years. For chemicals for which both cancer and non-cancer numbers exist, to be protective the lower level is used. Also, exceeding a CV does not mean that health effects will occur–just that more evaluation is needed.
CVs used in this document are listed below:
Environmental Media Evaluation Guides (EMEGs) are estimated contaminant concentrations in a media where non-carcinogenic health effects are unlikely. The EMEG is derived from the Agency for Toxic Substances and Disease Registry's (ATSDR) minimal risk level (MRL).
Remedial Media Evaluation Guides (RMEGs) are estimated contaminant concentrations in a media where non-carcinogenic health effects are unlikely. The RMEG is derived from the Environmental Protection Agency's (EPA's) reference dose (RfD).
Cancer Risk Evaluation Guides (CREGs) are estimated contaminant concentrations that would be expected to cause no more than one additional excess cancer in 1 million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factors (CSFs).
Preliminary Remediation Goals (PRGs) are the estimated contaminant concentrations in a media where carcinogenic or non-carcinogenic health effects are unlikely. The PRGs used in this public health assessment were derived using provisional reference doses or cancer slope factors calculated by EPA's Region 9 toxicologists.
EPA Soil Screening Levels (SSLs) are estimated contaminant concentrations in soil at which additional evaluation is needed to determine if action is required to eliminate or reduce exposure.
Evaluation of Public Health Implications
The next step is to take those contaminants that are above the CVs and further identify which chemicals and exposure situations are likely to be a health hazard. Child and adult exposure doses are calculated for the site-specific exposure scenario, using our assumptions of who goes on the site and how often they contact the site contaminants. The exposure dose is the amount of a contaminant that gets into a person's body.
Appendix B describes the assumptions used in calculating exposure dose for the pathway.
The calculated exposure doses are then compared to an appropriate health guideline for that chemical. Health guideline values are considered safe doses; that is, health effects are unlikely below this level. The health guideline value is based on valid toxicological studies for a chemical, with appropriate safety factors built in to account for human variation, animal-to-human differences, the use of the lowest adverse effect level, or a combination of all three. For non-cancer health effects, the following health guideline values are used.
Minimal Risk Level (MRLs) - developed by ATSDR
An estimate of daily human exposure–by a specified route and length of
time–to a dose of chemical that is likely to be without a measurable risk
of adverse, non-cancerous effects. An MRL should not be used as a predictor
of adverse health effects. A list of MRLs can be found at http://www.atsdr.cdc.gov/mrls.html.
Reference Dose (RfD) - developed by EPA
An estimate, with safety factors built in, of the daily, lifetime exposure of
human populations to a possible hazard that is not likely to cause non-cancerous
health effects. The RfDs can be found at http://www.epa.gov/iris/ .
If the estimated exposure dose for a chemical is less than the health guideline value, then the exposure is unlikely to cause a non-carcinogenic health effect in that specific situation. If the exposure dose for a chemical is greater than the health guideline, then the exposure dose is compared to known toxicological values for that chemical and is discussed in more detail in the public health assessment (see Discussion Section). These toxicological values are doses derived from human and animal studies summarized in the ATSDR toxicological profiles. A direct comparison of site-specific exposure and doses to study-derived exposures and doses found to cause adverse health effects is the basis for deciding whether health effects are likely or not.
The estimated risk of developing cancer from exposure to the contaminants was
calculated by multiplying the site-specific adult exposure dose by EPA's corresponding
Cancer Slope Factor (which can be found at http://www.epa.gov/iris/ ). The results
estimate the maximum increase in risk of developing cancer after 70 years of
exposure to the contaminant.
The actual risk of cancer is probably lower than the calculated number. The method used to calculate EPA's Cancer Slope Factor assumes that high-dose animal data can be used to estimate the risk for low dose exposures in humans. The method also assumes there is no safe level for exposure. But little experimental evidence exists to confirm or refute those two assumptions. Lastly, the method computes the 95% upper bound for the risk, rather than the average risk, suggesting that the cancer risk is actually lower, perhaps by several orders of magnitude.
Because of uncertainties involved in estimating carcinogenic risk, ATSDR employs a weight-of-evidence approach in evaluating all relevant data [6]. Therefore, the carcinogenic risk is described in words (qualitatively) rather than as only a numerical risk estimate. A numerical risk estimate must be considered in the context of the variables and assumptions involved in their derivation and in the broader context of biomedical opinion, host factors, and actual exposure conditions. The actual parameters of environmental exposures must be given careful consideration in evaluating the assumptions and variables relating to both toxicity and exposure.
APPENDIX B: EXPOSURE DOSE ASSUMPTIONS AND DISCUSSION OF HEALTH GUIDELINES
Comparison of Exposure Dose to Health Guidelines
Soil Ingestion
Exposure doses for soil ingestion were calculated in the following manner. The average concentration for soil, in mg/kg (or ppm), was multiplied by the soil ingestion rate for adults, 0.0001 kg/day, or children, 0.0002 kg/day. The multiplication product was divided by the average weight for an adult, 70 kg (154 pounds) or a child. For on-site soil contamination, a child's body weight of 36 kg (80 pounds) was used, given that the likelihood of an infant contacting on-site soil is very small. For residential, off-site exposure, a body weight of 10 kg (22 pounds) was assumed in residential soils and 36 kg was assumed for a child playing in ditch sediment. The result is the exposure dose, in units of mg/kg/day. These calculations assume daily exposure to soil contaminated at the average concentration shown for soil in contamination data tables.
Estimation of Dermal Exposure Doses from Sediment
For childhood exposure to ditch and sediments at the intersection of Rock Creek Road and Highway 18, a combined exposure dose of dermal contact and incidental soil ingestion was assessed. To calculate dermal exposure of a child playing in sediment, certain assumptions were made. The calculation assumes a 10-year old child weighing 36 kilograms (kg) with a body surface area of 13,500 square centimeters (cm2) [15]. A child wearing shorts, a short sleeve shirt and no shoes was estimated to have approximately 54% of exposed body surface area. It was also assumed that the child would play in the area 52 days out of the year, for a total of 6 years. The dermal absorption factors used were 3% for arsenic, 3% for dioxins and furans, and 13% for PAHs [16]. Incidental soil ingestion was calculated as described above.
Calculation of Risk of Carcinogenic Effects
Soil Ingestion
Carcinogenic risk from ingestion of soil was calculated through the following procedure. The adult exposure doses for soil ingestion (calculated as described previously) were multiplied by EPA's Cancer Slope Factor for ingestion of the contaminants of concern. The results represent the maximum risk for excess cancer after 70 years of exposure to the maximum concentration of the contaminant.
APPENDIX C: INHALATION EXPOSURE EVALUATION
The following is an evaluation of a past exposure pathway as these chemicals are not longer used at this facility to treat wood. Air samples were collected from three on-site locations and four sites of varying distance from the West Facility. Elevated levels of arsenic were detected on multiple days. Pentachlorophenol, PAHs, naphthalene and chromium were detected above comparison values as well. These results are presented in Table 6. None of the contaminants listed below exceeded health guidelines.
Table 6 - Air Contaminants Above Comparison Values
| Range in Air (ug/m3)* | Samples > DL†/Total | Samples > CV‡ | CV in ug/m3 | CV Source§ | |
| Arsenic | ND-0.005 | 47/48 | 39/48 | 0.0002 | CREG |
| Chromium | 0.00001-0.003 | 48/48 | 47/48 | 0.00008 | CREG |
| Methylnaphthalene | 0.006-5.2 | 49/49 | 7/49 | 3.1 | R9 PRG |
| Naphthalene | 0.008-13 | 48/48 | 10/48 | 3.1 | R9 PRG |
| Pentachlorophenol | ND-0.29 | 1/49 | 1/49 | 0.056 | R9 PRG |
| Phenanthrene | ND-3.8 | 47/49 | 1/49 | 3.1 | R9 PRG |
Toxicological Evaluation:
The maximum level of arsenic measured near Taylor Lumber was 5 nanograms pre cubic meter (ng/m3). Some cities have concentrations that range from 20 to 100 ng/m3 [17]. Based on the average concentration of arsenic detected in a limited number of air samples, no adverse health effects would be anticipated as a result of arsenic inhalation.
Inhalation of arsenic contaminated dust over a long period of time can result in irritation of mucous membranes in the nose and throat. Epidemiological studies have demonstrated that exposure to inorganic arsenic can lead to numbness, muscle weakness, tremors, agitation and memory loss. Exposure to arsenic in the air could increase the chance of developing lung or gastrointestinal cancer as well.
Inhalation of chromium compounds could affect the respiratory tract. Workers exposed to high concentrations of chromium have reported shortness of breath, cough, and wheezing. Liver, kidney, gastrointestinal and cardiac effects have been reported as well. Cancer of the respiratory system, especially the bronchial and nasal, has been associated with occupational exposure. Based on the calculated exposure doses, adverse health effects as a result of inhaling chromium compounds would not be expected. From 1977-1984, chromium in the ambient air of U.S. cities and rural areas ranged from 0.005 to 0.525 ug/m3 [18], higher than the maximum level of chromium measured near Taylor Lumber.
The remaining contaminants listed above were not frequently detected above their comparison value. No health effects would be anticipated from inhalation because exposure was to relatively low levels and infrequent.
APPENDIX D: ATSDR PLAIN LANGUAGE GLOSSARY OF ENVIRONMENTAL HEALTH TERMS
The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health agency with headquarters in Atlanta, Georgia, and 10 regional offices in the United States. ATSDR's mission is to serve the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances. ATSDR is not a regulatory agency, unlike the U.S. Environmental Protection Agency (EPA), which is the federal agency that develops and enforces environmental laws to protect the environment and human health. This glossary defines words used by ATSDR in communications with the public. It is not a complete dictionary of environmental health terms. If you have questions or comments, call ATSDR's toll-free telephone number, 1-888-42-ATSDR (1-888-422-8737).
General Terms
Other glossaries and dictionaries:
Environmental Protection Agency (http://www.epa.gov/OCEPAterms/ )
National Center for Environmental Health (CDC) (http://www.cdc.gov/nceh/dls/report/glossary.htm )
National Library of Medicine (NIH) (http://www.nlm.nih.gov/medlineplus/mplusdictionary.html )
