Hopewell Precision Area Contamination
Appendix E: Summary of Public Comments and Responses
This summary was prepared to address comments and questions on the public comment draft of the Hopewell Precision Area Contamination Public Health Assessment. The public was invited to review the draft during the public comment period, which ran from November 17th 2006 until January 19th 2007. A public meeting was held on January 22nd 2007 to discuss the document with the community and the deadline was extended until February 23rd 2007. NYS DOH received multiple written comments, and verbal comments from the meeting. A summary of these comments and NYS DOH's responses is included below:
Comment #1: The report lacks details, for example, about methods used to collect samples. Data are summarized but there are no references to the reports that provide details on how data were generated.
Response #1: It is beyond the scope of this document to provide details about sample collection and analysis methods; however, it is appropriate to include references for the information presented in the report and used in the assessment. The Reference section of this document includes all of the published or publicly available material used in preparing the assessment.
The US EPA expects to issue a Remedial Investigation Report next year. That report will include detailed descriptions of collection and analysis methods for all samples collected in support of the Remedial Investigation, including many of the samples discussed in this document.
Comment #2: The information in the report is two years old.
Response #2: The information in the report was current as of the spring of 2006, when the US EPA began their Remedial Investigation. The investigation will provide more information on the extent of the groundwater contamination, but such information is unlikely to change the basic conclusions and recommendations of the public health assessment. When the investigation is complete, ATSDR and NYS DOH will revisit the Public Health Assessment to determine whether the Public Health Action Plan should be changed or expanded.
Comment #3: The public health assessment says that the tetrachloroethene (PCE) found in soil vapor and indoor air and the methyl-tert-butyl ether (MTBE) found in private wells are not related to Hopewell Precision. Have the parties responsible for this contamination been found?
Response #3: No, they have not. We have recommended to the US EPA that additional investigation into the sources of these chemicals be undertaken.
Comment #4: How long will the US EPA's investigation of the Hopewell Precision Contamination site go on?
Response #4: The US EPA expects to finish field work for the investigation by the end of 2007. They estimate that the remedial investigation report would be issued early in 2008 and that a remedy would be proposed sometime in 2008.
Comment #5: Will the sub-slab depressurization systems and water treatment systems be the final remedy for this site?
Response #5: The remedy may include these systems at least as an interim measure, but it will probably also include other components designed to actively contain or remediate contaminated groundwater and sources of contamination. After the remedial investigation is complete, the US EPA will conduct a feasibility study, also in 2008, to evaluate potential remedies for the contamination. Based on that study, they will propose a remedy for the site. The public will have an opportunity to review and comment on the proposal before a final remedy is determined.
Comment #6: Water treatment and vapor mitigation systems should be maintained as long as necessary, and a permanent long-term remedy is needed for groundwater users.
Response #6: We have made these recommendations to the US EPA. At this time, the NYS DEC and US EPA plan to continue maintaining the treatment and mitigation systems. We have recommended that the US EPA consider a permanent, long-term remedy for groundwater users when evaluating potential remedies for the contamination.
Comment #7: How do I request to have my private well or air tested or retested?
Response #7: You may contact Lorenzo Thantu, the US EPA's project manager for the remedial investigation, at (212) 637-4240 to find out if your home is within the boundaries of US EPA's investigation and whether there are plans to collect additional samples at your home.
You may also wish to have water from your private well tested by an independent laboratory. For a list of approved laboratories in your area, as well as for other information about drinking water and private wells, you can contact the Dutchess County Department of Health's Environmental Health Services Division at 845-486-3404, 9 a.m. to 5 p.m., Monday through Friday.
Comment # 8: Wells outside the defined TCE plume should be tested as part of long-term monitoring plan, and wells that have already been tested that did not exceed state drinking water standards should be retested at least twice a year. The Hopewell Junction Citizens for Clean Water should be notified when these wells are tested and should be given the results.
Response # 8: The NYS DOH has shared this comment with the US EPA for their consideration in developing a long-term monitoring plan for the site. The details of that plan will be determined as part of the design of the overall remedy for the contamination, which is expected to begin sometime next year.
The US EPA will continue to monitor private wells in the area. The US EPA will notify property owners and tenants of the results of private well sampling.
Comment # 9: Homes where sub-slab vapor was tested but where sub-slab depressurization systems were not installed should be retested at least twice a year as part of a long-term monitoring plan. This includes homes eliminated from further vapor testing because sub-slab vapor concentrations of TCE were below the US EPA screening level of 2.7 micrograms per cubic meter, as well as homes with sub-slab vapor concentrations greater than 2.7 but less than 50 micrograms per cubic meter. Also, homes with sub-slab vapor concentrations greater than 50 micrograms per cubic meter, which were given sub-slab depressurization systems, should be tested to ensure that the indoor air meets the "post-remediation standard" of 0.38 micrograms per cubic meter.
Response # 9: The NYS DOH has shared this comment with the US EPA for their consideration in developing a long-term monitoring plan for the site. The details of that plan will be determined as part of the design of the overall remedy for the contamination, which is expected to begin sometime next year.
The US EPA will collect additional sub-slab vapor and indoor air samples at some homes in the area, depending on the results of previous sampling (if any) and the location of the homes relative to the known contamination. Once a sub-slab depressurization system is installed at a home, and its proper operation has been verified, additional vapor and air samples are not typically needed as long as the system is inspected periodically to ensure that it continues to operate as designed.
Comment # 10: Was the air sampled in the building at Red Wing Park?
Response # 10: No. To date, the vapor investigation has not gone south of Clove Branch Rd. At this time, the US EPA does not have evidence that the contamination extends that far.
Comment # 11: Does the soil vapor contamination pose an exposure concern for children playing on the ground?
Response # 11: No. Outdoor air has been sampled, and it has not shown evidence of site-related contamination. Soil vapor contamination is seldomly a significant source of outdoor air contamination, even at ground level, because vapors are quickly diluted by outdoor air.
Comment # 12: What action will be taken to address the contamination in surface water and sediment in small ponds? You may wish to consider fencing off or posting signs until contamination is cleaned up.
Response # 12: After the investigation is completed, the US EPA will consider potential remedies for all of the site-related contamination, including contamination in sediment and surface water. No actions have been taken at this time to address the contamination in the small ponds. These ponds are not used to supply water for drinking or other purposes, nor are they used for recreation, to the best of our knowledge. Transient exposure to the levels of contamination detected in the ponds does not pose a health concern.
Health Effects, Physician Information
Comment # 13: How can I get a packet of information regarding TCE exposure for my doctor?
Response # 13: A packet of information regarding TCE exposure has been provided to the person asking this question. Any other community members who wish to have such a packet sent to their physician or would like there own copy, should call 518-402-7880 or 1-800-458-1158, and ask to speak with Rebecca Mitchell. NYS DOH would also like the name and address of your physician. The packets include the following materials:
- An ATSDR Compact Disc (CD) of Case Studies in Environmental Medicine (CSEMs), with opportunities for earning many free CME credits through the Centers for Disease Control and Prevention. * Go to the CSEM specifically entitled "Trichloroethylene (TCE) Toxicity".
- A hard copy of both the "TCE Trichloroethylene (TCE) Toxicity" and "Taking an Environmental Exposure History" Case Studies
- A NYS DOH fact sheet on Trichloroethene (TCE) in Indoor and Outdoor Air
- ATSDR fact sheet on Trichloroethylene (TCE)
- A NYS DOH fact sheet on Tetrachloroethene (PERC) widely used in dry-cleaning.
- An ATSDR fact sheet on Tetrachloroethylene (PERC)
- An ATSDR fact sheet on 1,1,1-Trichloroethane (1,1,1-TCA)
Comment # 14: Residents should have access to "doctors trained in this field" who "know what types of testing need to be done because of our exposure."
Response # 14: Environmental medicine is not a common specialty among physicians. Those who specialize in Public Health and Preventive Medicine and/or Occupational Medicine are generally the most knowledgeable about chemical exposures and toxicology. In trying to identify an environmental health physician nearby, you can try the following methods:
- You or your personal physician may want to contact one of the clinics in the New York State Occupational Health Clinic Network. The New York State Occupational Health Clinics are recognized centers of excellence, providing a unique blend of diagnostic and prevention services for occupational disease. The clinics in this network offer specialized medical diagnoses, high-quality care and support services for workers with occupational and environmental disease. They can medically evaluate patients who have experienced environmental exposures and they will accept most health insurances and Medicaid. The two following clinics have satellite offices in areas within a moderate distance of the East Fishkill area:
- The Occupational and Environmental Health Center of Eastern New York has an office in New Paltz. To contact this clinic for an appointment, call 518-690-4420 or 1-800-419-1230.
- The Mt. Sinai IJ Selikoff Center for Occupational and Environmental Medicine of Mt. Sinai School of Medicine has an office in Yonkers. To contact this clinic for an appointment, call 914-964-4737.
- You may Ask your primary care physician if he or she can provide a referral, or
- Call your local or a nearby County Medical Society or the Medical Society of the State of New York for a list of appropriate physicians, or
- Search for the above mentioned specialties in your county or nearby on the NYS Department of Health web site at http://www.nydoctorprofile.com/search_parameters.jsp.
Comment # 15: The synergistic effects of exposure to multiple chemicals, including TCE, PCE, and MTBE, should be considered in this assessment.
Response # 15: Our evaluation of potential chemical interactions, including synergy, is discussed under "Consideration of Interactions among Environmental Chemicals." It is found in Part D of the Discussion section of the document.
Comment # 16: "Kidney cancer from TCE carries a unique toxic fingerprint. Residents should be informed of this, and educated on this mutation. Those who agree to genetic testing should be accommodated. This would be very much in line with what CDC is doing for Fallon and Sierra Vista, as well as the beryllium testing in Ohio at Brush Wellman Plant."
Response # 16: Somatic mutations leading to an inactivation of the Von Hippel-Lindau (VHL) tumor suppressor gene are considered a risk factor for kidney cancer. They are only considered risk factors because it remains debatable whether mutations in the VHL gene alone are sufficient to trigger the cancer response in the kidney (NAS, 2006).
Studies have shown increased mutations in the VHL gene of kidney cancer patients exposed to high concentrations of TCE, and evidence suggests an association between TCE exposure and a unique genetic signature (i.e., a pattern of mutations). Genetic testing of people with kidney cancer could determine whether the mutations have taken place, but would not provide conclusive evidence that the changes were caused by TCE exposure rather than some other factor that can induce genetic signatures similar to that of TCE. Given these uncertainties, we consider it premature to test residents for mutations in the VHL gene as a means of identifying those at risk for kidney cancer related to TCE exposure. Individuals wishing to learn more about the VHL gene and the merits of genetic testing are advised to consult a physician or genetic counselor familiar with genetic testing.
VOC Exposure Registry
Comment # 17: At some point, NYSDOH should share information from the VOC Exposure Registry with other state health agencies so that a more cohesive picture of the adverse health effects of TCE and other contaminants in our water, soil and air can be realized sooner than later.
Response # 17: Information from any summaries of VOC Exposure Registry data and/or results of studies which use VOC Exposure Registry data will be shared with all stakeholders including residents of Registry communities, interested members of the general public, as well as local, county, state or federal agencies. In addition, if positive findings result from studies using VOC Exposure Registry data, these results will be communicated through the scientific literature and the information will be made available to other states through our federal partner ATSDR. All personal identifying information about individual VOC Registry participants is strictly confidential. No individual-level information will ever be provided in reports or summaries.
Comment # 18: "Epigenetics is proving that toxicants can tweak the function of our genes without mutating. We are learning such exposures have multi-generational effects beginning in the womb. This is an opportunity to learn from the community through real life exposure cases what health effects can manifest as disease in the future. It is my understanding that the TCE sub registry from the past was found to be lacking. Has this resource been updated and improved?"
Response # 18: Although NYS DOH does not have a statewide registry specifically for TCE exposure, the VOC Exposure Registry does include a number of sites where TCE was the primary contaminant. ATSDR established a National Exposure Registry that contains four subregistries, one of which is the TCE Subregistry. More information is available about the National Exposure Registry and the TCE Subregistry on ATSDR's website at: http://www.atsdr.cdc.gov/NER/index.html
Health Statistics Review
Comment # 19: A health statistics review (like the one done near the IBM site in Endicott, NY) should be done to determine whether the people living near this plume have elevated rates of health effects.
Response # 19: NYS DOH will conduct a health statistics review of cancer and birth outcomes for the Hopewell Precision area. NYS DOH scientists met with residents in March 2007 to define the appropriate study area boundaries to be used in the review. While the review may show an elevation in certain cancer or birth outcomes among Hopewell residents, this type of study is not capable of determining whether exposure to contamination from the Hopewell Precision site caused any particular adverse health effect.
Comment # 20: Would a health statistics review include everyone living over the plume or only select residents, like those who have enrolled in the VOC registry?
Response # 20: Once the appropriate study area boundaries have been determined, the health statistics review will include all individuals within the study area.
Comment # 21: Will NYSDOH track down past residents?
Response # 21: The health statistics review will include cancer and adverse birth outcomes diagnosed among Hopewell area residents who lived in the study area during the study time period (roughly 1980-2004). If past residents of the Hopewell area do not meet these criteria, but are interested in the results of the review or have any questions, comments or concerns regarding the VOC Exposure Registry, they are encouraged to contact Ms. Megan Meldrum of the NYS DOH at 518-402-7950 or 1-800-458-1158.
Comment # 22: What disease would be an indicator of exposure?
Response # 22: Certain health outcomes have been shown in the scientific literature to be associated with TCE exposure. However, it is important to keep in mind that there are several risk factors for all of these health outcomes, including lifestyle and genetic factors. Therefore the occurrence of these outcomes does not necessarily indicate exposure to TCE or other environmental contaminants.
Epidemiologic studies of women living in areas where drinking water has been contaminated with TCE or PCE or women occupationally exposed to TCE and other solvents have suggested an increased risk of several types of birth defects as well as several other adverse birth outcomes including cardiac defects, oral clefts, neural tube defects, spontaneous abortion, low or very low birth weight and small for gestational age. Available epidemiologic studies provide evidence for a positive association between occupational TCE exposures and several types of cancer in humans, most notably liver/biliary cancer, kidney cancer, non-Hodgkin's lymphoma, esophageal cancer, and to a lesser extent Hodgkin's disease and cervical cancer. Human epidemiologic studies do not provide evidence to support the identification of TCE as a risk factor for lung cancer and testicular tumors. Nonetheless, potential TCE air criteria are derived from animal studies showing that TCE caused liver cancer, kidney cancer, lung cancer, testicular tumors, and malignant lymphoma in animals.
TCE Action Levels/Standards
Comment # 23: Did the NYSDOH use the most current information on TCE exposure when they drafted this public health assessment?
Response # 23: We used the most recent available information on exposure (e.g., the sampling results for indoor air and private wells), toxicity, and used currently accepted risk assessment practices to evaluate the health risks associated with contaminants at the Hopewell Contamination area.
Comment # 24: New York State's action levels are higher than those of California or Oregon. Those states have adopted the maximum contaminant levels suggested by the 2002 EPA draft review of TCE's toxicity: 1 ppb for drinking water and 0.020 mcg/cu.m. for indoor air in Oregon and 0.017 mcg/cu.m. in California. NYSDOH should err on the side of caution and use these levels.
Response # 24: The air values cited for California and Oregon are based on the 2001 (not 2002, as is stated in the comment) US EPA Draft Health Assessment Document entitled "Trichloroethylene Health Risk Assessment: Synthesis and Characterization" (US EPA, 2001). This draft assessment was review by the US EPA's Scientific Advisory Board (SAB), which made extensive and detailed comments on the methods used to evaluate the toxic potency of TCE. Following the SAB review, an expert panel was convened by the National Academy of Sciences (NAS) Board on Environmental Studies and Toxicology, which identified critical scientific issues that should be addressed in any health risk assessment of TCE. The draft US EPA Health Assessment is undergoing revision. The final document is expected to address the SAB's comments and incorporate the findings of the NAS report (NAS, 2006).
Therefore, the values presented in the original report (US EPA, 2001) are subject to change, including the estimate of cancer potency on which the air values cited in the comment (0.02 and 0.017 micrograms per cubic meter (mcg/m3)) are based. This cancer potency estimate comes from a single study on the association between cancer rates (e.g., non-Hodgkin's lymphoma) in New Jersey towns and drinking-water levels of volatile organic chemicals (VOCs), including TCE, in the same towns. The use of this study to derive an air level for TCE is not supported by the information in the study for several reasons. First, it is a drinking water study, and inhalation studies should be used to derive an air guideline when such studies are available, as they are for TCE. Second, the study lacks vital information on the level and duration of exposure to TCE, and therefore does not meet criteria for using an epidemiology study for quantitative risk assessment. Third, chemicals other than TCE were in the drinking water supplies, and therefore whether the observed increases in risk are due to TCE or one of the other chemicals is not known. We therefore did not use this study to derive a cancer potency factor to quantify the cancer risks of TCE exposures. This conclusion is supported by the expert NAS (2006) panel on TCE, which stated, "None of the existing epidemiologic data is suitable as a primary means of quantifying cancer risks."
The New York State air guideline for TCE (5 mcg/m3) was derived using standard and accepted risk assessment procedures and was peer reviewed by a panel of independent experts (NYS DOH, 2006a). The TCE air guideline is set at a level lower than those that cause health effects and assumes people (including sensitive individuals such as infants and children) are exposed 24 hours per day and seven days per week for a lifetime. The TCE air guideline is one aspect of the Soil Vapor/Indoor Air Matrix 1, which is New York State's decision-making tool for remediation of TCE contamination resulting from soil vapor intrusion. The matrix recommends actions based on background, sub-slab and indoor air levels of TCE, and does not rely solely on the air guideline. For example, the matrix recommends mitigation of TCE exposures when TCE is present in sub-slab vapor at 250 mcg/m3 or higher even when TCE is not detected in indoor air. Our soil vapor intrusion guidance document (NYS DOH, 2006b) also recommends that reasonable and practical measures should be taken to reduce TCE exposure when indoor air levels are above background, even when they are below the guideline of 5 mcg/m3. Thus, the TCE air guideline is not a threshold below which no action is taken.
As per New York State's approach to mitigating soil vapor intrusion into indoor air, Soil Vapor/Indoor Air Matrix 1 was used to make decisions about remediation at the Hopewell Precision site. This included an evaluation of TCE indoor air levels that are above and below the air guideline of 5 mcg/m3.
Cancer Risk Language:
Comment # 25: "The determination that a concentration of 250 mcg/L of TCE in well water poses a "low" cancer risk for residents consuming this water is not based on any scientific analysis. It is simply a subjective judgment, an opinion, offered as "fact" when it clearly is not. The US EPA drinking water standard that defines a safe and acceptable concentration for consuming drinking water is set at 5 mcg/L. How can a value that is 50 times higher than this standard, that is also based on the risk of developing cancer, be defined as having a "low increased risk for cancer (i.e., the estimated risk is between one-in-one million and one-in-ten thousand)" (PHA, p. 15)? It appears that DOH is trying to assure the public that everything is "OK," regardless of the scientific evidence, various uncertainties, and the presence of clearly identified risks. This classification contradicts the findings made last year by a committee of the National Academies that concluded in part that the "evidence on carcinogenic risk and other health hazards from exposure to trichloroethylene has strengthened since 2001" and that "there is strong evidence that exposure to high doses of trichloroethylene is associated with increased rates of kidney cancer." Defining 250 mcg/L TCE in drinking as a "low increased risk" is misleading and a disservice to the public."
Response # 25: The use of the term "low" does not refer to the qualitative weight-of-evidence that TCE is a human carcinogen, but to our standard qualitative descriptor for levels of estimated excess lifetime cancer risk (see Appendix C of the Public Health Assessment). Based on our procedure for evaluating health risks and assigning qualitative descriptors, increased lifetime cancer risks between 1 per 1,000,000 and 1 per 10,000 are given the qualitative descriptor of "low." The estimated increased cancer risk for exposure to 250 mcg/L TCE (3.4 per 100,000) is within this range. Because of the uncertainties associated with these cancer risk estimates, these estimates cannot be used in an actuarial sense to predict the number of actual cancer cases. Rather they are used to help make decisions about the need and urgency of action to reduce exposures. The exact degree of risk at low levels may never be known because the risk is generally too small or too confounded by other factors to measure in the general population, particularly given the large background rates of cancer (1 in 2 for men and 1 in 3 for women) in the general population.
Characterization of the increased cancer risk as "low" does not mean that there is no risk, or that measures to reduce exposure are not needed. In fact, the estimated risk is in the range of excess cancer risks that are generally used by regulatory agencies
for taking actions (1 per 1,000,000 to 1 per 10,000), and as stated before, measures to reduce exposure were initiated at the site. The characterization of the risk associated with exposure to 250 mcg/L TCE as "low" means that the estimated increased cancer risk is relatively small, and that the level of exposure, although above the drinking water standard, is still well below the TCE exposure levels that have been shown to cause cancer in laboratory animals. A step-by-step calculation of the estimated increase cancer risk from exposure to 250 mcg/L TCE in drinking water is presented in Attachment 1 of these responses to comments.
Comment # 26: " I am also concerned that the wording in the TCE section of the Public Health Implications on pages 14 – 15 is misleading to those effected by this contamination. The families that lived on top of this contamination plume were most likely exposed to unhealthful levels of TCE for years in their homes. Potentially, this means that people without jobs, such as older retired residents, homemakers and small children, were exposed to these levels 24 hours a day, 7 days a week. Studies that I have read noted that two of the three groups of people I just mentioned are more likely to be susceptible to TCE exposure: the elderly and children. Although a dose – response continuum has not been established (because of uncertainties in exposure levels, duration of time exposed, and confounding factors such as smoking or alcohol consumption), this should not minimize concern for residents.
"I think the wording of the last paragraph of the TCE section is the most concerning. The health implications for being exposed to the TCE levels in the drinking water were described as "posing a low increased risk for cancer". However, on page 47 The NYS DOH "Qualitative Descriptors for Excess Lifetime Cancer Risk" describes the excess cancer risks associated with the exposure of the Hopewell Precision Site. It would be better to write in that section that the residents have a low increase of excess risk for cancer. The excess risk measurement is what is important. The general public is told everyday that if they don't do this or do that then they risk an increase in developing cancer of one sort or another. For example, public service announcements on television advise that if you don't eat enough fiber, you may increase your risks for colon cancer. Other announcements say if you breathe second-hand smoke you increase your risk of developing lung cancer. Eating fiber and staying out of smoky rooms are then factors people have the power to control. I have never seen a public service announcement by a celebrity telling the public not to drink contaminated water with TCE let alone other chemicals or not to breathe the vapors of TCE. Most of the general public is unaware of the adverse health effects associated with VOC exposure. Therefore, exposure to undetected toxic contamination is not within a person's power to control and is appropriately termed "excess" risk. This is the terminology that should be used in the public health implications to accurately depict the increased health risks that the exposed citizens of the Hopewell Precision Site may face."
Response # 26: The first portion of the comment expresses concern that the health risks for TCE be evaluated for continuous exposure and for people who may be especially sensitive to TCE. In the public health assessment, we evaluated health risks at the Hopewell Precision site assuming that residents were exposed to site-related contaminants in indoor air and drinking water on a continuous basis for 29 years (corresponding with the start of industrial activity at the Hopewell Precision facility). For contaminants in indoor air, we assumed the exposure was without interruption for 24 hours per day, 7 days per week. For contaminants in drinking water, we assumed that a person drinks 2 liters of water per day containing the chemicals and also is exposed through nondrinking uses of the water, such as showering or bathing. In our risk characterization, we also considered the possibility that infants and children may be especially sensitive to TCE exposure in light of the fact that their nervous systems are rapidly developing. Thus, our exposure estimates are inclusive of people who may be especially sensitive to the effects of TCE and who may have spent a significant portion of their time in their homes. In reality, residents are unlikely to have stayed in their homes continuously, and their exposure to site-related contaminants was probably intermittent (i.e. discontinuous). In addition, the exposure duration is likely to have been shorter than 29 years because the movement of contamination to groundwater, private drinking water wells, soil gas and indoor air could have taken a significant amount of time. Therefore, the exposure assumptions used in the public health assessment probably result in an overestimation of actual exposures at the site.
The second issue raised in the comment concerns the terminology used in the public health assessment to describe the estimated cancer risks resulting from exposure to site contaminants. The term "increased risk for cancer" refers to the extra (or excess) risk (probability) of developing cancer over the lifetime of an individual resulting from exposure to site-related contaminants. The risk for cancer associated with site-related exposures is termed increased (or excess) because it is in addition to pre-existing background cancer rates which are attributable to other risk factors unrelated to the contamination area.