PUBLIC HEALTH ASSESSMENT
CENEX SUPPLY AND MARKETING, INCORPORATED
(a/k/a WESTERN FARMERS, INCORPORATED)
QUINCY, GRANT COUNTY, WASHINGTON
APPENDIX C: SOIL CONTACT EXPOSURE ASSUMPTIONS
Both oral (ingestion) and dermal (skin contact) routes of exposure were evaluated for the 11 contaminants of concern detected in site soil. Maximum detected contaminant concentrations were conservatively used to estimate exposures, even if the level was from a sample detected below ground surface. Dust inhalation exposures were evaluated separately (see Table A15 and Appendix D). The following soil contact exposure assumptions were used in the health assessment:
APPENDIX D: EXPOSURE DOSE FORMULAS
Soil Ingestion Exposure Dose
IDs = (Cs) (IR) (CF) (EF) (ED) / (BW) (AT)
where
IDs = Soil ingestion exposure dose (mg/kg/day)
Cs = Contaminant concentration in soil (mg/kg)
IR = Soil ingestion rate (mg/day)
CF = Conversion factor for soil (0.000001 kg/mg)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (duration over which exposure is averaged-days). For noncarcinogenic
effects AT = (ED x 365 days/year); for carcinogenic effects AT = (70 years x
365 days/year), or 25,550 days
Soil Dermal Exposure Dose
AD = C x CF x SA x AF x ABS x EF x ED)/(BW x AT)
where
AD = Absorbed dose (mg/kg/day)
C = Chemical concentration in soil (mg/kg)
CF = Conversion factor (10-6 kg/mg)
SA = Skin surface area available for contact (cm2/event)
AF = Soil-to-skin adherence factor (mg/cm2)
ABS = Absorption factor (unitless)
EF = Exposure frequency (events/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (duration over which exposure is averaged-days). For noncarcinogenic
effects AT = (ED x 365 days/year); for carcinogenic effects AT = (70 years x
365 days/year), or 25,550 days.
EPA Particulate Emission Model
Inhaled dose (ID) from particulates (modeled)
Particulate Emission Model Assumptions
PEF = particulate emission factor (m3/kg) = 6.59 x 10 8
Respirable fraction (g/m2-hr) = 0.036
V = fraction of vegetative cover (unitless) = 0.001
Um = mean annual wind speed (m/s) = 4.69
Ut = equivalent threshold value of wind speed at 10 m (m/s) = 11.32
F(x) = function dependant on Um/Ut (unitless) = 0.194
Q/C (m3/kg) = 90.8
CF(s/hr) = 3600
C = Concentration (mg/kg)
IR = inhalation rate (m3/day):
child = 8.3
older child = 14
adult = 15.2
EF = exposure frequency (days/year) = 350
BW = body weight (kg):
child = 15
older child = 41
adult = 72
AT = averaging time (days)
ED = exposure duration (years)
APPENDIX E: INTERIM CRITERIA OF ACTIONS FOR LEVELS OF PUBLIC HEALTH HAZARD FROM PHA GUIDANCE MANUAL, 1992
Revision Effective May 1, 1999
Category A : Urgent Public Health Hazard
This category is used for sites where short-term exposures (< 1 yr) to hazardous substances or conditions could result in adverse health effects that require rapid intervention.
This determination represents a professional judgment based on critical data that ATSDR has judged sufficient to support a decision. This does not necessarily imply that the available data are complete; in some cases additional data may be required to confirm or further support the decision made.
Criteria
Evaluation of available relevant information* indicates that site-specific conditions or likely exposures have had, are having, or are likely to have in the future, an adverse impact on human health that requires immediate action or intervention. Such site-specific conditions or exposures may include the presence of serious physical or safety hazards, such as open mine shafts, poorly stored or maintained flammable/explosive substances, or medical devices which, upon rupture, could release radioactive materials.
* Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data.
ATSDR Actions
ATSDR will expeditiously issue a health advisory that includes recommendations
to mitigate the health risks posed by the site. The recommendations issued in
the health advisory and/or health assessment should be consistent with the degree
of hazard and temporal concerns posed by exposures to hazardous substances at
the site.
On the basis of the degree of hazard posed by the site and the presence of sufficiently defined current, past, or future completed exposure pathways, one or more of the following public health actions can be recommended:
Category B: Public Health Hazard
This category is used for sites that pose a public health hazard due to the existence of long-term exposures (> 1 yr) to hazardous substance or conditions that could result in adverse health effects.
This determination represents a professional judgment based on critical data that ATSDR has judged sufficient to support a decision. This does not necessarily imply that the available data are complete; in some cases additional data may be required to confirm or further support the decision made.
Criteria
Evaluation of available relevant information* suggests that, under site-specific conditions of exposure, long-term exposures to site-specific contaminants (including radionuclides) have had, are having, or are likely to have in the future, an adverse impact on human health that requires one or more public health interventions. Such site-specific exposures may include the presence of serious physical hazards, such as open mine shafts, poorly stored or maintained flammable/explosive substances, or medical devices which, upon rupture, could release radioactive materials.
*Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data.
ATSDR Actions:
ATSDR will make recommendations in the health assessment to mitigate the health
risks posed by the site. The recommendations issued in the health assessment should
be consistent with the degree of hazard and temporal concerns posed by exposures
to hazardous substances at the site. Actions on the recommendations may have occurred
before the actual completion of the public health assessment.
On the basis of the degree of hazard posed by the site and the presence of sufficiently defined current, past, or future completed exposure pathways, one or more of the following public health actions can be recommended:
Category C: Indeterminate Public Health Hazard
This category is used for sites when a professional judgment on the level of health hazard cannot be made because information critical to such a decision is lacking.
Criteria
This category is used for sites in which "critical" data are insufficient with regard to extent of exposure and/or toxicologic properties at estimated exposure levels. The health assessor must determine, using professional judgment, the "criticality" of such data and the likelihood that the data can be obtained and will be obtained in a timely manner. Where some data are available, even limited data, the health assessor is encouraged to the extent possible to select other hazard categories and to support their decision with clear narrative that explains the limits of the data and the rationale for the decision.
ATSDR Actions
ATSDR will make recommendations in the health assessment to identify the
data or information needed to adequately assess the public health risks posed
by the site.
Public health actions recommended in this category will depend on the hazard potential of the site, specifically as it relates to the potential for human exposure of public health concern. Actions on the recommendations may have occurred before the actual completion of the public health assessment.
If the potential for exposure is high, initial health actions aimed at determining the population with the greatest risk of exposure can be recommended. Such health actions include:
If the population of concern can be determined through these or other actions, any of the remaining follow-up health activities listed under categories A and B may be recommended.
In addition, if data become available suggesting that human exposure to hazardous substances at levels of public health concern is occurring or has occurred in the past, ATSDR will reevaluate the need for any followup.
Category D: No Apparent Public Health Hazard
This category is used for sites where human exposure to contaminated media might be occurring, might have occurred in the past, and/or might occur in the future, but the exposure is not expected to cause any adverse health effects.
This determination represents a professional judgment based on critical data that ATSDR considers sufficient to support a decision. This does not necessarily imply that the available data are complete; in some cases, additional data might be required to confirm or further support the decision made.
Criteria
Evaluation of available relevant information* indicates that, under site-specific exposure conditions, exposures to site-specific contaminants in the past, present, or future are not likely to result in any adverse impact on human health.
*Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data; monitoring and management plans.
ATSDR Actions
If appropriate, ATSDR will make recommendations for monitoring or other
removal and/or remedial actions needed to ensure that humans are not exposed to
significant concentrations of hazardous substances in the future. Actions on the
recommendations may have occurred before the actual completion of the public health
assessment.
The following health actions, which may be recommended in this category, are based on information indicating that no human exposure is occurring or has occurred in the past to hazardous substances at levels of public health concern. One or more of the following health actions are recommended for sites in this category:
However, if data become available suggesting that human exposure to hazardous substances at levels of public health concern is occurring, or has occurred in the past, ATSDR will reevaluate the need for any followup.
Category E: No Public Health Hazard
This category is used for sites that, because of the absence of exposure, do NOT pose a public health hazard.
Criteria
Sufficient evidence indicates that no human exposures to contaminated media have occurred, none are now occurring, and none are likely to occur in the future.
ATSDR Actions
No public health actions are recommended at this time because no human exposure is occurring, has occurred in the past, or is likely to occur in the future that may be of public health concern.
APPENDIX F: RESPONSE TO PUBLIC COMMENTS
Comment 1: Why is the concentration of a chemical in air, water, or soil, which is expected to cause no more than one additional cancer in 1 million persons or one in 100,000 persons over a lifetime, acceptable?
When assessing cancer risks in environmental exposure assessment, the term "acceptable" is typically used to define an exposure(s) in which the risk of developing cancer is still thousands of times lower than the likelihood of the general population developing cancer during their lifetime (i.e., 1 in 4 chance). The term "acceptable" is thus a subjective "line in the sand," which most health and environmental regulatory agencies use in assessing whether further site cleanup is necessary, or whether to recommend actions to reduce or eliminate exposures. Recommendations for reduction or elimination of exposures and environmental cleanups are typically justified at sites where exposures are occurring, or could occur in the future, and the estimated increased cancer risk is greater than 1 in 10,000 or 1 in 100,000.
Comment 2: Who paid for the soil removal; taxpayers or Cenex? Cenex should pay. An example should be made so that other corporations who pollute the environment understand they must "clean up their act."
Cenex paid for the soil removal and has assumed the liability and costs for investigation and cleanup of the Cenex site.
Comment 3: The draft health assessment clearly indicated I was concerned about the smell of diesel exhaust in my classroom. That is correct. The point I tried to make was either not understood, or excluded from the report. To clarify or reiterate, I am not overly concerned with the smell of diesel exhaust, but rather I used it as an example to illustrate how quickly smells (and therefore any air-born particulates, including those from the Cenex site) enter into the classrooms. At some point in time, air movement would have carried drift toward the junior high school. The filter system does not begin to address that level or type of filtration necessary to provide a clean, safe environment for teachers and students. What was the exposure level for staff and students in the building during the rinsate pond's peak use?
Since no sampling of the rinsate pond overspray was conducted during its brief operation in the 1980s, measurement of junior high school staff and student exposures to the overspray is not possible. On the basis of the concentrations and limited number of herbicide/pesticide compounds reported for a single rinsate pond sample, and the limited time in which the exposures would have occurred, a long-term health threat would not be expected.
In January 1998, WDOH was contacted by the commenter regarding concerns expressed about indoor air quality at the junior high school, including concerns about dust accumulation in the school's ventilation system. WDOH followed up the conversation with a letter dated January 21, 1998. WDOH responses to comments # 8 and # 22 in the draft health assessment.(p. 36 and p. 44, respectively) summarized the content of the 1998 letter. WDOH had indicated at the time that it did not think dust accumulation in the ventilation system (if present) posed an immanent health threat. Using an EPA particulate emission model, WDOH has since attempted to estimate a "worst-case" dust inhalation scenario, assuming someone was exposed at the site to dust containing the highest levels of all Cenex site soil contaminants of concern. The results of the modeling effort indicate that health risks from dust inhalation would have been below a level of health concern The results are presented in Table A15.
Comment 4: Your report states that if I have concerns, I should investigate possible health-related issues with my health care provider, yet neither you nor your office ever contacted me to make that suggestion or statement. All information I have received from your office has repeatedly assured me there was no reason for concern. Why wasn't I contacted and told I should follow up with my health care provider if I continued to have concerns?
On the basis of the results of all available Cenex site environmental sampling data, WDOH has no reason to believe that a health threat existed for staff or students at either of the schools. The results of the August 2000 indoor air sampling event conducted inside the high school revealed no site-related contaminants. ATSDR prepared a health consultation evaluating the August 2000 air sampling results and determined that chemicals detected in air at the Quincy high school (as well as the background schools) were not at levels of health concern, and do not pose a health hazard.
Although WDOH concluded that the site did not pose a public health threat to school staff or students, WDOH has indicated numerous times at public meetings that anyone with ongoing health concerns should see their primary care physician.
Comment 5: On April 11th, I believe, while again running a group of kids by the trees next to the Cenex site, I smelled what I believe was the same chemical that I smelled during the operation of the rinse/concentrating pond. Are any processes currently (this spring) going on which could conceivably allow fumes to escape into the atmosphere?
For a number of years, with Ecology oversight, Cenex has conducted various activities at the site, including soil vapor extraction, soil gas testing, new monitoring well installation, monitoring well testing, and testing of air sparging. It is conceivable that one or more of these activities could have resulted in localized, short-term odors, although WDOH is unaware of any particular occurrence. Ecology can be contacted for specific site-related activities and timeframes.
Comment 6: The report spoke of ingestion as the pathway into the human body. What about absorption through skin contact? What about inhalation? I did not see either of these entrance routes mentioned in the report. I believe both of these are much more likely routes of exposure. I mentioned, as noted in the report, the salty taste I kept spitting up, and the acidic burning I noticed in my eyes. Why haven't inhalation and absorption been addressed as points of possible entry?
The health assessment assumed that exposures to contaminated soil occurred as a result of both ingestion and absorption through the skin (dermal absorption). Since the draft health assessment, WDOH has evaluated the dust inhalation pathway using an EPA particulate model. The modeled results indicate that exposure to site contaminants from dust inhalation would have been below a level of health concern. The results are presented in Table A15.
Comment 7: I believe this report is incomplete and therefore inaccurate. I would like to see a more complete study. There are questions about the sensitivity of the test badges used in the schools to determine exposure. Yet, the badges were not in place during peek times of possible exposure. Shouldn't accumulated dust from around the filter sites or air ducts also be examined?
On the basis of all available information (epidemiological data, site-specific environmental sampling data, indoor air sampling data, and particulate modeling results), WDOH concluded that the site posed a low health risk, and does not agree that a community health study is warranted. WDOH agrees that the original (February 1998) indoor air sampling investigation at the high school was not an appropriate method for obtaining VOC air samples. Results of a more recent (August 2000) and appropriate indoor air sampling investigation revealed no site-related contaminants, and no contaminants at levels of health concern. The testing was conducted to determine if VOCs present in groundwater and soil gas had migrated into high school buildings. WDOH and ATSDR recommended another round of indoor air testing in the high school during a different season to verify that site-related VOCs are not present at levels of health concern. This was done in November 2001, the results of which will be evaluated in a separate health consultation.
As a general indoor air quality recommendation, the school's heating, ventilation, and air conditioning (HVAC) system should periodically be inspected and cleaned. WDOH was informed that the high school HVAC system was completely replaced within the last several years. The previous system brought in outside air. The current system is a forced air system which circulates air within the confines of the building. WDOH was also informed that the junior high school HVAC system was replaced 10-12 years ago. The Washington State Department of Labor and Industries, private air quality consulting firms, and/or certified industrial hygienists should be contacted if further assistance is needed on these issues.
Comment 8: The conclusion: "No Apparent Public Health Hazard" is not justified because, based on our analysis of the cancer rates in Table 2, the table contains inaccurate calculations. The assessment's conclusion: "the number of cases occurring in Quincy was not different than what would be expected in a community of the same size and structure" could therefore be wrong. Our re-evaluation of Table 2 shows that the occurrence of Non-Hodgkins Lymphoma is significantly higher than expected at the 95% confidence level. That is a type of cancer that is associated with farm communities and herbicides. Because different citizens who came to discuss their health problems with the Department of Health mentioned renalcell carcinoma and bladder cancer, we checked kidney and renal pelvic cancer numbers at the 90% confidence level and found the occurrence of kidney and renal pelvic cancer is significantly higher than expected at the 90% confidence level. We found additional problems with the calculations and urge you to re-evaluate the numbers.
At the request of a Quincy resident, we expanded the analysis of incident cancer cases occurring in Quincy to include all 24 cancer sites, cancers with unknown primary site (i.e., cancers diagnosed at an advanced stage for which it was impossible to determine the site where the cancer began), all other cancers, and all cancers combined, using all available data (i.e., 1992-1998). Further, we used an analytical technique which presents the results differently. The procedure used in the previous draft constructed 95% confidence intervals around the observed number of cases and observed whether this interval included the expected number of cases.This analysis is easy to perform and is typically used as a screening tool. For the final health assessment, we conducted statistical tests that assess how likely it is to have the observed number of cancer cases if the actual cancer rate in Quincy was the same as the state as a whole. We presented the resulting p-values, which estimate the probability of having the observed number of cases, or a number of cases which is even further from the expected number of cases based on the overall state average. This analysis was conducted for all cancer sites, and for all cancers combined, using all 7 years of available data for the Quincy zip code 98848.
This analysis indicates that the total number of cancer cases is significantly less than would be expected, and that there were significantly fewer cases of lung and bronchus cancer. "Unknown primary site" was the only category for which there was a statistically significant excess number of cancer cases than would be expected. Since these cases were different types of cancer, it is very unlikely that they would have had a common underlying cause. Non-Hodgkin's lymphoma was not statistically elevated, with 11 observed cases and 10.3 expected cases (p = 0.680). There were 10 cases of kidney and renal pelvis cancer, with an expected value of 6. This difference was not statistically significant (p = 0.09).
The analysis conducted by the statistician working for the community members was somewhat different than that initially used by WDOH. In that analysis, the statistician assumed a Poisson distribution with a mean equal to the expected number of cancer cases and, for the cases where the observed was greater than expected, estimated the probability of getting at least the observed number of cases. This is roughly equivalent to conducting a one-tailed test where the alternative hypothesis is that the observed value is greater than the expected. In our current analysis, we use the same procedure, but we use two-tailed tests, where the alternative hypothesis is that the observed value is not equal to the expected value. That is, it might be higher or lower. This accounts in part for the different results obtained using these two methods.
Comment 9: Even without what might be an excess of cancers, it would be better to delay a final conclusion until you have the data from the additional tests at the high school and other testing.
Prior to finalization of this health assessment, WDOH expanded the analysis of incident cancer cases (see response to previous comment). In addition, WDOH evaluated dust inhalation exposures, three additional contaminants, and received the results of indoor air samples collected at the high school. On the basis of these data, and data already evaluated, WDOH feels there is sufficient information upon which to draw an overall health conclusion. If additional testing is conducted, WDOH can prepare a separate health consultation report evaluating the data.
Comment 10: I think the site warrants recommendation for a Community Health Investigation, one of the actions that could potentially accompany the "No Apparent Public Health Hazard" conclusion.
On the basis of WDOH's evaluation of all available site-related chemical information, and health outcome data for the Quincy area, WDOH does not agree on the need for a community health investigation.
Comment 11: No house dust was sampled in the community or at the high school. Citizens asked questions about house dust but the answers were not helpful. Dust can be a reservoir of past contamination from pesticides, which certainly could have occurred in Quincy, even though some of the site is now cleaned up.You could also request that the dust in the air filters at the high school be tested. Some schools do not clean them regularly.
See response to comment # 3 and # 7.
Comment 12: Better testing of the high school air should be done. In particular, lower detection levels for 1-2 DCP should be used.
WDOH agrees that the original (1998) indoor air quality investigation was inadequate. A more recent (August 2000) high school indoor air investigation was performed using EPA Test Method T0-14, which had greater sensitivity and reliability than the original 3-M badge tests. The August 2000 test results did not reveal any Cenex site-related chemicals. ATSDR prepared a health consultation report summarizing those results. To verify that site-related VOCs are not present in the high school at levels of health concern, WDOH and ATSDR recommended a similar indoor air sampling investigation inside the high school during a different season. Another indoor air investigation was conducted at the high school in November 2001. When available, the results will be evaluated in a separate health consultation.
Comment 13: Has local data been checked regarding the number of children with learning disabilities or the relative funds spent on this problem in the Quincy schools, compared to other school districts? Elizabeth Guillette found that in Mexico there is a big difference in the cognitive abilities of children who live and work in agricultural areas compared to children who live far from such sites.
WDOH has not checked the local data regarding the number of children with learning disabilities or the relative funds spent on this problem in the Quincy schools, compared to other school districts. WDOH has found some information in the scientific literature that suggests higher incidences of some cancer types for pesticide applicators and children living in agricultural areas, compared to nonagricultural areas (see WDOH response to comment # 1 in the draft health assessment). The purpose of this health assessment, however, was to evaluate the potential health risks associated with the Cenex site, not potential health risks as a result of areawide pesticide use. The commenter can refer to the Discussion section for a detailed evaluation of the health risks.
Comment 14: The groundwater is quite contaminated. Can't the Department of Health recommend testing if citizens are concerned about other wells? Although the health assessment says there are no other known private wells in the area, I understand there is a trailer park to the northeast with private wells. Also, EDB contamination at the Nielson Trailer park was mentioned by citizens interviewed for the health assessment.
WDOH does not regulate private domestic wells. We can provide well-testing recommendations, information on certified testing laboratories, and evaluate the results of such testing. WDOH has worked with Grant County to identify all at-risk wells (i.e., wells hydraulically downgradient of the Cenex site). To date, no individual domestic wells have been identified that are threatened by contaminants from the Cenex site. The area of groundwater contamination has been extensively studied through regular monitoring of at least 29 monitoring wells, and source removal and treatment is ongoing.
WDOH sampled for EDB in the Quincy area in the early 1990s as a result of contamination in a nearby water system. The sampling revealed contamination in the Neilson Trailer Park (now Country Corner) wells, located south of town. WDOH provided the system operator with health-effects information and directed the operator to distribute it to the water users. The system is under order to conduct quarterly monitoring, provide a small water system plan, obtain water system approval, and notify consumers about the chemical detections (Scott Fink, Ginny Stern, and Valori Adams, WDOH Drinking Water Division, personal communication, November 2000). EDB was found to be a regional problem following testing conducted by Ecology in the mid 1990s. EDB groundwater contamination has also been an issue in Whatcom and Thurston counties.
Comment 15: Why was there no specific attention to workers at the site, health problems in their families, etc.? They certainly suffered the highest exposures.
The results of the health assessment indicate that past exposure to site contaminants would have resulted in only a low health risk. Per state and federal occupational health requirements, employees should have appropriate health and safety training tailored to the specific chemicals handled during the course of their work. The Washington State Department of Labor and Industries (L&I) would be the appropriate agency to investigate and evaluate worker exposures. L&I have inspectors and certified industrial hygienists whose primary function is to inspect, regulate, and monitor worker exposures.
Comment 16: Sometimes ATSDR health assessments take into consideration other sources of contamination (businesses, spraying of various kinds, disposals, and spills) in the community. Your approach might be because the request to WDOH was to assess problems caused by Cenex, but the site has likely exacerbated other problems caused by agricultural chemicals, and this possibility should not be ignored. The Grant County Local Emergency Planning Committee, which collects information about chemicals used, stored, and released by facilities in the community, would be a good source of information.
WDOH agrees that the Grant County Local Emergency Planning Committee could be a valuable resource for general areawide issues related to the storage, handling, use, and transportation of hazardous materials. The purpose of this health assessment was to evaluate potential health risks associated with the Cenex site.
Comment 17: I understand that no citizens have formally requested a study, but on the basis of past contamination from pesticide use and releases, and the concern expressed by the community members you interviewed, it might be helpful if the Department of Health could recommend that ATSDR do a health study for the Quincy community. Then other sources of toxins could be included.
See responses to comment # 7 and # 10.
Comment 18: ATSDR is looking at new research possibilities involving exposures to mixtures of chemicals, and also at some of the health problems that are on the rise, especially in children: asthma, attention deficit disorder, etc. The WDOH could recommend the Cenex site for research, since the toxic site was so close to a school and some of the children's parents might work there.
On the basis of the results of all available site environmental sampling data and health outcome data, WDOH has no plans to recommend that ATSDR conduct this type of research for the Cenex site. The kind of research the commenter suggests would require a larger exposed population, and exposures to contaminants at levels considerably higher than were present at the Cenex site.
Comment 19: We find the quality of the public health assessment conducted at the former Cenex Fertilizer and Fumigant Storage Facility in Quincy, Washington, to be of shoddy quality. Deficient in effort and scientific data, the conclusion of "very low risk" from past, present, and future exposures is questionable, if not suspect.
See response to previous comment. At the request of some residents, the following additional information was evaluated and included in the final health assessment; 1) evaluation of three additional contaminants, 2) evaluation of dust inhalation using an EPA particulate model, and 3) an expanded evaluation of incident cancer cases for the Quincy area. This results of WDOH's evaluation of this additional information did not change WDOH's overall health conclusion.
Comment 20: From a past exposure perspective, there was little or no effort made by WDOH to explore the health of persons known, or suspected, to have been exposed tocontaminants during the operation of the site. Specifically, no effort was made to contact students and teachers present at the Junior and Senior High Schools during the 1986-1990 operating period of the Cenex site, nor to contact residents of adjacent neighborhoods. Cenex employees and others working in the area, e.g., Desert Electric employees, also were not contacted.
On the basis of our evaluation of all available site environmental sampling and community epidemiological data, WDOH concluded that the risk to the community as a result of the Cenex site was not high. Specific community health concerns are addressed in detail in the health assessment.
Comment 21: While interviews with past students, teachers, and Cenex employees (full- and part-time) would have provided the most accurate insight into exposure and past risk from the site, this was not done. Instead, estimates were made by assuming that the only route of exposure to chemicals on the site were from oral ingestion and dermal contact, as children and workers would have walked the site. No analysis was done of dust in the schools, or soils on the school property--now, or in the past.
WDOH sponsored an Open House in 1997 to hear health concerns from area residents. Those concerns are addressed in the health assessment. Data indicated that the site posed only a low health risk, and did not warrant the kinds of interviews the commenter suggests. Prior to removal of stockpiled contaminated soil/concrete in 1997, a small number of pesticides, herbicides, and metals were present at elevated levels at the site. Current soil contaminant levels are much lower, and the entire site has been covered with 6 inches of clean gravel. Regardless of the level of risk, WDOH has always maintained its availability to assist school staff or students with individual health concerns. At the request of the school district, Ecology and WDOH follow-up indoor air testing was conducted there in August 2000. The results did not reveal any site-related contaminants, and, on the basis of ATSDR's evaluation of the data, do not pose a health threat to students or staff at the high school. To verify that site-related VOCs are not present at levels of health concern, another round of indoor air sampling was conducted inside the high school (and at background locations), in November 2001.
In the health assessment, WDOH evaluated the potential health risks to persons who were assumed to be exposed to contaminated dust generated at the Cenex site using an EPA particulate emission model. The model indicated that exposures to contaminated dust originating from the site would not have posed a public health hazard (see Table A15).
Comment 22: Air quality monitoring, which had been discussed with WDOH repeatedly in 1996-97 while contaminated soils were on the site, was refused. Without this information, as you have pointed out, past exposure estimates via this most critical of pathways (inhalation) cannot be done--a major deficiency of this report which is directly attributable to the nonfeasance of the WDOH.
See responses to previous comments regarding dust exposures. The EPA particulate emission model referenced previously indicates that the health risks from inhalation of site soil contaminants would have been below a level of health concern.
Comment 23: Exposure estimates have been limited to only those chemicals on the site which exceeded MTCA cleanup standards. Alachlor, Atrazine, and Thallium also exceeded cleanup standards, but were not assessed.
WDOH estimated exposures for contaminants detected in soil or soil/sludge samples that exceeded ATSDR health comparison values. If an ATSDR value was not available for a particular contaminant, MTCA method B soil clean-up levels or EPA risk-based concentrations (RBCs) were used to screen contaminants for further evaluation (see data tables). Alachlor, atrazine, and thallium have been included as contaminants of concern, are discussed in the health assessment, and are included in the data tables.
Comment 24: The second issue relates to current exposure to the site, specifically the 1,2-dichloropropane spill that has now migrated under the high school. The technology used for assessing concentrations of 1,2-DCP in the high school was inappropriate. Ambient air tests run in February 1998 were conducted with the approval of the WSDOE using a technology whose detection limit was set higher than the reference concentration, the outcome of which might lead a trusting populace to believe that there was only one "hit" in the high school, as reported. The fact is the levels of exposure to students and teachers in Quincy High School remain unknown. Any conclusion of "low risk" from faulty data is remiss on the part of WDOH. Furthermore, it has now been over 2 years since Health and Ecology recognized this deficiency, yet nothing has been done by these agencies to facilitate timely and appropriate re-analysis to determine what concentrations might be present in Quincy High School. To remedy this deficiency, full air quality "canister" monitoring should be employed in not only the high school, but the adjacent junior high school as well.
Use of the 3-M passive dosimeter badges was not the appropriate method to measure indoor air VOC concentrations at the high school. More reliable and sensitive canister testing was conducted in the high school in August 2000, and no site-related contaminants were detected. To verify that site-related VOCs are not present in the high school at levels of health concern, another indoor air sampling investigation was conducted in November 2001. When the data become available, WDOH will evaluate the results.
On the basis of discussions with Ecology, the location and direction of the groundwater plume does not indicate that the junior high school is at any greater (and likely less) risk than the high school. If subsequent investigations indicate the presence of elevated levels of VOCs underneath the junior high school, or if the results of the most recent indoor air testing at the high school reveal site-related VOCs at levels of health concern, WDOH would consider recommending similar indoor air sampling for the junior high school.
Comment 25:The third area of concern are assumptions being made without supporting data. This includes assuming that
(a) The 1,2-DCP spill is not migrating "upgradient" towards two city wells and over a dozen private wells. To remedy this uncertainty, monitoring wells should be placed "upgradient" to prove there is no migration in that direction and drinking water wells should be tested for 1,2-DCP.
The only drinking water well identified to date that could conceivably be threatened by the Cenex groundwater plume is Quincy municipal well # 5, located about ½ mile east-southeast of the site. Well 5 draws water from a deep (340-350 feet below ground surface) aquifer. The presence of an intermediate confining layer is believed to restrict the movement of water between wells screened in the upper aquifers and wells screened at the same depth as municipal well # 5 (Feasibility Study, p. 4-3). The results of water level measurements from shallow and deep monitoring wells on and near the site indicate that groundwater flow in the Quincy area and underneath the site is toward the southeast (Feasibility Study, p. 4-2 and 4-4, and Figures 4.3 and 4.4). Quincy municipal wells #1, #2, #3, and #4 are located hydraulically upgradient (west) of the site, and should not be threatened by the Cenex groundwater plume. All five of the Quincy wells are Group A public water supply wells, and are regulated by WDOH. Because of the increasing threat of chemical contamination to Quincy municipal wells as a result of general areawide pesticide use, WDOH has been more closely evaluating the wells and has required more frequent sampling. The most likely use of the affected shallow groundwater is irrigation. Previous discussions and well investigations conducted by Grant County and WDOH did not locate any at-risk domestic wells adjacent to or downgradient of the site, in the vicinity of the contaminated groundwater plume.
(b) The Junior High School is not affected by the 1,2-DCP spill. With students at, or entering, puberty at this school, this student population is most vulnerable and should be included in all air quality monitoring efforts, and any soil and/or dust studies that are undertaken.
See response to comment # 24.
(c) Rates of cancer, other than the 10 mentioned in the health consult, are within expected ranges for our area. All cancers should be reviewed, not just 10, and the years of review should be expanded to include all available information. (Please note, that non-Hodgkin's lymphoma and kidney and renal pelvis cancer rates are double what would be expected for a community of our population (Table 2, page 46), but have been shown to fall within a range of "expected values" through a statistical tool called a "95% Poisson Confidence Interval."
See response to comment # 8.
Comment 26: Finally, there are several discrepancies between the earlier draft of the health assessment and the one released to the public. Among these discrepancies are
(a) A reduced number of estimated cancers per chemical in the final draft.
Changes in the estimated increased cancers since the original draft were probably a result of slight revisions of exposure factors for individual chemicals, or slight revisions of exposure assumptions used in the health assessment.
(b) Language describing the hydrogeology of the aquifer into which the 1,2-DCP has spilled. The latest version has removed all references to "fractures and faults in the basalt" which make up the layers separating the aquifers, and to analysis performed that demonstrates groundwater "movement vertically" between the aquifers. Removal of this key language might support claims attributed to you by the Wenatchee World that "the two aquifers are separated by a thick layer of clay that water cannot pass through"--a statement clearly erroneous to a reader of the first draft.
Studies (i.e., pumping tests) have indicated little or no vertical connection between the shallow and deep water bearing units, and thus little chance that contaminants in the upper aquifer could impact the deeper aquifer. Any changes made in the health assessment concerning the nature and characteristics of the regional hydrogeology and lithology were intended to reflect the most recent information available. WDOH defers to the Remedial Investigation and Feasibility Study reports for a more complete discussion of local and regional hydrogeology and lithology.
(c) "BGS" is defined as "Below Ground Surface" in the narrative of the earlier document but not in the report released to the public. Instead, BGS is footnoted in the final document as "Background soil South," presumably referring to a background soil sample south of the junior high athletic field. Or does this mean that this sample was taken from below ground surface? It's interesting that the background soil sample wasn't taken from the north side of the athletic field where it might have represented drift from the site onto school property--something that still should be done.
The "BGS" reference on page 13 of the draft health assessment refers to the depth "below ground surface" of Quincy's municipal wells. The full name and acronym was indicated on page 13. The "BGS" acronym from Table 9, p. 64, of the draft health assessment refers to the background soil sample collected from the south border of the Quincy junior high school athletic field, and is indicated in a footnote below Table 9.
Comment 27: WDOH's deliberate use of inadequate and misleading information to arrive at the conclusion that there is a "very low past health risk" associated with the site is unacceptable and insulting. It demonstrates a lack of professionalism, a lack of concern for the people, and a bias toward corporate interests. Testing needs to be conducted to correct deficiencies noted in the public health assessment; to rule out current exposures to residuals from the site; and to expand the scope of testing to include the junior high school and neighboring residents. In addition, historical and geographical information should be reviewed for accuracy and corrected as needed.
On the basis of WDOH's review of all Cenex site environmental sampling and community epidemiological information, WDOH does not agree that additional environmental testing is warranted at the junior high school and neighboring residences. If the follow-up indoor air sampling conducted at the high school in 2001 reveals contaminants at levels of health concern, WDOH could recommend similar sampling for the junior high school. On the basis of the particulate emission model referenced previously, it is unlikely that past airborne exposures to contaminated dust from the site would have resulted in chronic health problems. Residual levels of pesticides remaining on the site are low and do not pose a health threat. In 1997, the site was covered with 6 inches of gravel, further reducing the chance for exposures. The current remedial action objectives include various proposals intended to further reduce the chances for exposures, such as asphalt capping of the site.
This public health assessment was prepared by the Washington State Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the health assessment was begun.
Debra Gable
Technical Project Officer, SPS, SSAB, DHAC
ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment and concurs with the findings.
Richard Gillig
Chief, SPS, SSAB, DHAC
ATSDR
