PUBLIC HEALTH ASSESSMENT
PETER COOPER-MARKHAMS
[a/k/a PETER COOPER CORPORATION (MARKHAMS)]
DAYTON, CATTARAUGUS COUNTY, NEW YORK
The Peter Cooper-Markhams site is in the Town of Dayton, near the Hamlet of Markhams, Cattaraugus County, New York, about six miles southwest of the Village of Gowanda. The Peter Cooper Corporation (PCC) acquired the Markhams site in 1955. The site is about 100 acres in size and the surrounding area is rural and sparsely populated.
From 1903 to 1985, the PCC made glue and adhesives from animal hides at their facility in Gowanda. From 1955 to 1972, the PCC disposed of about 9,600 tons of residual solids from their manufacturing process at the Markhams site. In 1972, the PCC moved about 38,600 tons of waste from their Gowanda facility to the Markhams site. Except for investigation and remedial work, the site has been undisturbed since 1972.
In 1989, a disposal area was identified which contained drums. Subsequently, the drums and visibly contaminated soils were removed from this area. The nearly 300 drums contained oils and off-specification glues. The drums and contaminated soils were properly disposed off-site and the excavation was backfilled with clean soil, graded and seeded. The Peter Cooper-Markhams site was placed on the National Priorities List in January, 2000.
No public meetings have been held regarding this site. However, the public was invited to review a draft of this public health assessment during the public comment period, which ran from September 26 to December 15, 2001. The main health concern expressed was whether their drinking water was contaminated from the site.
The Cattaraugus County Health Department collected samples from four private drinking water wells in 1986 and no site-related contaminants were detected. The US EPA sampled one residential well in 2000 and also did not find contamination. Although site-related contaminants are unlikely to be migrating to off-site wells, the NYS DOH, Cattaraugus County Health Department and the US EPA will review groundwater quality and flow direction data from future investigations at the site to determine whether any further sampling of water from private wells is needed.
At the request of the Chairman of the Cattaraugus County Solid Waste Committee, the NYS DOH is reviewing cancer incidence data for the Village of Gowanda, the Cattaraugus Indian Reservation and the Towns of Perrysburg, Persia, Dayton, New Albion, and Otto.
Based on the information reviewed, the Peter Cooper Markhams site poses an indeterminate public health hazard. Although there are no known exposures, environmental data from the site are limited. Specifically, a better understanding of groundwater conditions and possibly further sampling of private wells is needed. The limited data that are currently available indicate that long-term exposure to the highest level of arsenic detected in surface water could pose a low increased cancer risk to unauthorized visitors to the site. Also, total chromium in surface soil at the highest levels detected could cause allergic skin reactions in unauthorized visitors. However, because of the remote location and current knowledge of site conditions, the potential for frequent and long-term exposure is limited and such adverse health effects are unlikely.
The NYS DOH and/or the ATSDR will work with the US EPA in determining what additional environmental data need to be collected. The NYS DOH and ATSDR will re-assess the public health hazard category for this site when these additional data are available.
BACKGROUND AND STATEMENT OF ISSUES
The purpose of this public health assessment is to evaluate past, current and potential future exposures to site-related contaminants. It fulfills the congressional mandate for a public health assessment for each site being proposed to the National Priorities List (NPL). Under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR), the New York State Department of Health (NYS DOH) will evaluate the public health significance of the Peter Cooper-Markhams site. More specifically, ATSDR and NYS DOH will determine whether health effects are possible and will recommend actions to reduce or prevent possible health effects. ATSDR is a federal agency within the U.S. Department of Health and Human Services and is authorized by the Comprehensive Environmental Response, Compensation, and Liability Act Superfund Amendments and Reauthorization Act (SARA) of 1986, to conduct public health assessments at hazardous waste sites proposed for the NPL. The Peter Cooper-Markhams site was proposed for the NPL April 1999 and placed on the NPL January 2000.
A. Site Description and History
The Peter Cooper-Markhams site (the Markhams site) is in the Town of Dayton, near the hamlet of Markhams, Cattaraugus County, about six miles southwest of the Village of Gowanda (Figure 1, Appendix A). The Peter Cooper Corporation (PCC) acquired the Markhams site in 1955 (O'Brien & Gere Engineers, Inc., 1991). The property is about 100 acres in size and the surrounding area is rural and sparsely populated. Most of the surrounding land is used for farming. Except for investigation and remedial work, the site has been undisturbed since 1972.
From 1903 to 1985, the PCC made glue and adhesives from animal hides at their facility in Gowanda. From 1955 to 1972, the PCC disposed of about 9600 tons of residual solids from their manufacturing process at the Markhams site. In 1972, as a result of a New York State Department of Environmental Conservation (NYS DEC) order, the PCC moved about 38,600 tons of waste from their Gowanda facility to the Markhams site (O'Brien & Gere Engineers, Inc., 1989). The wastes were primarily piled onto the ground surface into 20-foot high mounds that were arranged in a semi-circle in the disposal area. The PCC used about seven acres of the property for waste disposal.
Prior investigations included magnetometer surveys in 1984 and a remedial investigation/feasibility study (under NYS DEC order) conducted by the PCC in 1986. In 1989, as a result of these investigations and a review of disposal records, another disposal area was identified. Subsequently, drums and visibly contaminated soils were removed from this area by a consultant for the NYS DEC. The nearly 300 drums contained oils and off-specification glues. The drums and contaminated soils were properly disposed off-site and the excavation was backfilled with clean soil, graded and seeded.
Disposal of hazardous waste, as defined by NYS (in 6NYCRR Part 371), was not found at either Peter Cooper Corporation sites. Therefore, both the Markhams site (this site) and the Gowanda site, were removed from the NYS Registry of Inactive Hazardous Waste Disposal Sites in 1992. The Peter Cooper-Gowanda Site was placed on the US EPA NPL in 1998 and subsequently re-listed on the NYS registry. A Public Health Assessment for the Peter Cooper-Gowanda site was released on August 31, 2000 (ATSDR 2000). Since the majority of the wastes at the Peter Cooper- Markhams site originated from the Gowanda site, this site was likewise placed on the NPL and re-listed on the NYS registry in 2000.
The US EPA is conducting a remedial investigation/feasibility study. The goal of a remedial investigation is to identify the nature and extent of contamination at the site. The feasibility study is a detailed evaluation of possible remedial alternatives that could be used to address contamination at the site.
On May 3, 2000, Ms. Dawn Hettrick of the NYS DOH and Mr. Gary Beck of the Cattaraugus County Health Department visited the Peter Cooper-Markhams site. The site is located within a wooded parcel with dirt road access. Although a gate is present near the entrance of the dirt road, it was open the day of the site visit. A short walk into the parcel is a structure that appears to be natural gas well. There is evidence of human activity in several locations on the property, such as footprints, beverage cans and disposal of furniture. Small and large footprints were found, indicating that both children and adults walk on the property. The waste piles are located well within the property, away from the paved roadway. However, the dirt roads go up to and around the waste piles and provide relatively easy access to the site. The waste piles appear to be well covered, but holes were dug, presumably by animals, into the piles at several locations. No obvious odors, particularly any that could be associated with the waste, were evident.
The NYS DOH estimated from the 1990 Census (US Bureau of the Census 1991) that 71 people live within one mile of the site. This population is 98.6% white and 1.4% American Indian. Based on the 1990 census 7% of the population is under six years of age, 22.5% is 6-19 years of age, 52.1% is 20-64 years of age, and 18.3% is 65 years or older. In 1990, there were 13 females of reproductive age (ages 15-44) in the area. The median household income for census county/tract/block group number 009/9605.00/2 was $25,486 in 1989, with 8.8% of the population living below the poverty level (US Bureau of the Census 1992). The following chart compares these demographics with statewide averages. There are no schools or nursing homes in the area.
| Age Distribution | New York State | Area within 1 mile of site |
| <6 | 8.3% | 6.7% |
| 6-19 | 18.4% | 22.5% |
| 20-64 | 60.2% | 52.1% |
| >64 | 13.1% | 18.3% |
| Race Distribution | ||
| White | 74.4% | 98.6% |
| Black | 15.9% | 0% |
| Native American | 0.3% | 1.4% |
| Other | 9.4% | 0% |
| Ethnicity Distribution | ||
| Percent Hispanic | 12.3% | 0% |
| 1989 Median Income | $32,965 | $25,486 |
| % Below Poverty Level | 13.0% | 8.8 |
A. Environmental Contamination
Samples of soil, waste, groundwater, surface water and sediments were collected on-site and analyzed during several investigations and a removal action. Most of the samples were only analyzed for a few contaminants that are suspected to be the primary contaminants at this site.
The metals antimony, arsenic, chromium, copper, silver and zinc occur naturally, but these metals were found at concentrations in excess of what would be considered naturally occurring (background concentrations) in soil and sediments. Hexavalent chromium, which can be associated with industrial waste and its presence is due to man-made materials, was also found at this site. In addition to metal contamination, several organic contaminants were found, including volatile organic compounds and semi-volatile organic compounds. However, analyses for organic compounds were performed on a small percentage of the samples that were collected.
Arsenic was found at levels up to 25 milligrams per kilogram (mg/kg) in surface soil samples, which slightly exceeds the expected background range of 2 to 20 mg/kg. Total chromium was found in concentrations up to 69,000 mg/kg which greatly exceeds the expected background levels of 10 to 60 mg/kg. Copper, silver and zinc were found at concentrations up to 120 mg/kg, 13 mg/kg and 990 mg/kg, respectively. The expected background concentrations for these are 2 to 40 mg/kg, 0.1 to 0.4 mg/kg and 20 to 200 mg/kg, respectively.
In subsurface soil, arsenic, chromium and hexavalent chromium were found at levels up to 28 mg/kg, 20,200 mg/kg and 169 mg/kg, respectively. Antimony was found at concentrations up to 9 mg/kg, which exceeds expected background levels of less than 1 mg/kg to 2 mg/kg.
In sediment, arsenic was found up to 30 mg/kg, chromium was found up to 130 mg/kg, copper was found up to 85 mg/kg, silver was found up to 7 mg/kg and zinc was found up to 870 mg/kg. Hexavalent chromium was not found in sediment samples.
Since there are no known routes by which people are being exposed to contaminants from the Markhams site, this section identifies potential exposure pathways associated with past, present and future use of the site. An exposure pathway is a process by which an individual may be exposed to contaminants originating from the site. An exposure pathway has five elements: (1) a contaminant source; (2) environmental media and transport mechanisms; (3) a point of exposure; (4) a route of exposure; and (5) a receptor population.
The source of contamination is the source of contaminant release into the environment, which at the Markhams site are the waste disposal areas. Environmental media and transport mechanisms carry contaminants from the source area to points where people may be exposed, such as surface soil, surface water, sediment or groundwater. The exposure point is the location where people may come in contact with site-related contaminants, such as on-site or drinking water from a private well. The route of exposure is how the contaminant may enter the body, such as ingestion, inhalation or dermal contact. The receptor population are people who may be exposed to contaminants at the point of exposure, such as unauthorized visitors (e.g., trespassers) to the site.
A completed pathway only exists when all five of these elements exist. A potential pathway exists when any one of the five criteria for an exposure pathway is missing. At the Markhams site, only potential exposure pathways have been identified. Based on the site visit there is evidence that people have been on-site, but it is unlikely they are being exposed to contaminants on-site since the wastes appear to be adequately covered. An exposure pathway is considered to not be completed when one of the five criteria has not existed in the past, does not currently exist, and will not exist in the future.
Potential ingestion of contaminated groundwater
The area around the Markhams site uses private wells to obtain drinking water. The Cattaraugus County Health Department collected samples from four private drinking water wells in 1986 and no site-related contaminants were detected. The samples were analyzed for some metals and volatile organic compounds. The US EPA sampled one residential well in December, 2000 and also did not find contamination. This water sample was analyzed for volatile organic chemicals, semivolatile organic chemicals, pesticides, PCBs and metals. Although site-related contaminants are unlikely to be migrating to off-site wells, more information is needed to determine the direction of groundwater flow from the site.
On-site groundwater is contaminated with arsenic, chromium and zinc at levels above water quality standards/guidelines and health comparison values (see Table 1). These groundwater samples were not analyzed for volatile and semi-volatile organic compounds. Also, there are limited off-site groundwater data and the extent of the groundwater contamination has not been defined. Therefore, this pathway cannot be evaluated further at this time.
Potential direct contact and incidental ingestion of surface soil, surface water, or sediments
Unauthorized visitors to the site, such as hunters, may come into direct contact with or accidentally ingest contaminated surface soil, surface water or sediment while on-site. The on-site surface water and sediments are in small wetland areas from which contaminants are not expected to move. Silver levels in the sediments exceed background levels but do not exceed health comparison values. Therefore, exposure to contaminants in sediments will not be discussed further. In on-site surface water, arsenic and chromium exceed water quality standards and guidelines, and arsenic exceeds its public health assessment comparison values (see Table 2). These contaminants in surface water are discussed below. Chromium in surface soil exceeds background levels, but not health comparison values; however, it is discussed below.
Potential exposures to waste and subsurface soil
Levels of chromium, copper and zinc in on-site wastes exceed soil background levels. Levels of antimony, arsenic, chromium, copper, silver and zinc exceed background levels in subsurface soil. However, the levels found in waste and sub-surface soil do not exceed health comparison values for non-residential exposure. Since exposed waste has not been observed during site visits, people are currently unlikely to be exposed to waste. Likewise, unless people dig at the site, exposure to contaminants in subsurface soil is unlikely. Therefore, exposures to subsurface soil or waste have not been evaluated.
Change in site use
The general area is a mixture of residential and agricultural properties and this site could be considered for these uses in the future. If residential or agricultural uses are considered for the site, potential exposures should be re-evaluated.
An analysis of the toxicological and epidemiological implications of the potential human exposure pathways of concern is presented below. To evaluate the potential health risks from contaminants of concern associated with the Peter Cooper-Markhams site, the NYS DOH assessed the risks for cancer and noncancer health effects. The risks of health effects depend primarily on contaminant concentration, exposure route, exposure frequency and duration. Additional information on the NYS DOH assessment for this site is presented in Appendix C. Although there are people visiting the site, the wastes appear to be covered and exposure pathways are limited. We evaluated potential exposures to contaminants in surface water and surface soil assuming no remediation takes place.
Potential ingestion and dermal exposure to contaminants in on-site surface water.
Exposure to contaminants in surface water could occur via incidental ingestion and dermal contact for people who access the Peter Cooper-Markhams site. Arsenic was detected in on-site surface water at a level, up to 104 micrograms per liter (mcg/L), that exceeds water quality standards and guidelines, and its public health comparison value based on carcinogenic effects (Table 2). Arsenic is a known human carcinogen. Studies of people exposed to high levels of arsenic in drinking water in foreign countries provide evidence of an association between arsenic ingestion and skin cancer. Currently there is a debate within the scientific community about the quantitative uncertainties in the US EPA's cancer potency factor and epidemiology studies of Taiwanese populations exposed to arsenic in drinking water (ATSDR 1993a). The existing data suggest that long-term exposure to the highest level of arsenic detected in on-site surface water (104 mcg/L) could pose a low increased cancer risk to unauthorized visitors to the site. The levels of chromium in on-site surface water also exceed water quality standards and guidelines, but did not exceed public health comparison values (Table 2). This evaluation probably overestimates the actual risk since the location of the site and current knowledge of site conditions make long-term human exposure to contaminants in on-site surface water unlikely. The noncancer risk for exposure to arsenic in on-site surface water would be minimal.
Potential dermal exposure to contaminants in on-site surface soil.
None of the contaminants detected in on-site surface soil exceed public health assessment comparison values based on incidental ingestion. Chromium was detected in on-site surface soil at levels well in excess of typical background levels. Dermal exposures to high levels of chromium compounds (including hexavalent chromium) have resulted in allergic reactions, particularly in people who are very sensitive to chromium. These allergic reactions are characterized by redness and swelling of the skin (ATSDR 1993b). The existing data suggest that dermal exposure to the highest levels of total chromium or hexavalent chromium detected in on-site surface soil (up to 69,000 mg/kg and 850 mg/kg, respectively) could cause such allergic reactions in some unauthorized visitors to the site.
At the request of the Chairman of the Cattaraugus County Solid Waste Committee the NYS DOH is reviewing cancer incidence data for the Village of Gowanda, the Cattaraugus Indian Reservation and the Towns of Perrysburg, Persia, Dayton, New Albion, and Otto. The results of health statistics reviews of such a broad area must be interpreted with caution, however, since there are less than 75 people living within a mile of the site and there is no evidence that the residents within the immediate area of the site were ever exposed to any contaminants from this site.
In addition, the NYS DOH maintains several health outcome databases, which could be used to generate site-specific health outcome data if warranted. These databases include the cancer registry, the congenital malformations registry, the heavy metals registry, the occupational lung disease registry, vital records (birth and death certificates) and hospital discharge data information.
E. ATSDR Child Health Initiative
The ATSDR Child Health Initiative emphasizes examining child health issues in all of the agency activities, including evaluating child-focused concerns through its mandated public health assessment activities. The ATSDR and the NYS DOH considers children when evaluating exposure pathways and potential health effects from environmental contaminants. We recognize that children are of special concern because of their greater potential for exposure from play and other behavior patterns. Children sometimes differ from adults in their susceptibility to hazardous chemicals, but whether there is a difference depends on the chemical. Children may be more or less susceptible than adults to health effects from a chemical and the relationship may change with developmental age.
The area around the Peter Cooper-Markhams site is rural and sparsely populated. Therefore, we would not expect young children to be exposed at levels of health concern because of the remoteness of the site and because most contaminants are not located on the ground surface. However, the NYS DOH/ATSDR will re-evaluate children's health issues as more data on the site become available.
No public meetings have been held regarding this site. However, the public was invited to review a draft of this public health assessment during the public comment period, which ran from September 26 to December 15, 2001.
Comment: Several residents expressed concern about the potential for their drinking water to become contaminated from the site. They also expressed a desire to have their drinking water sampled.
Response: The Cattaraugus County Health Department collected samples from four private drinking water wells in 1986 and no site-related contaminants were detected. The US EPA sampled one residential well in 2000 and also did not find contamination. Although site-related contaminants are unlikely to be migrating to off-site wells, the NYS DOH, Cattaraugus County Health Department and the US EPA will review groundwater quality and flow direction data from future investigations at the site to determine whether any further sampling of water from private wells is needed.
Comment: Residents do not want more dumping on the site.
Response: The site is not a permitted facility for receiving solid or hazardous waste. In addition, we relayed this concern to the US EPA for their consideration. The US EPA is overseeing the remedial investigation and eventually the implementation of a remedy.
Comment: A resident asked about whether the chemicals disintegrate with time and whether they can be altered chemically.
Response: Most of the contaminants found at the site are metals, which do not disintegrate or degrade with time. Metals can, however, bond with other elements to make them more or less stable in the environment. Sometimes, metals at hazardous waste sites are treated chemically to make them less available for human contact. Data from the remedial investigation will be evaluated to determine the potential for human contact and off-site migration. Alternative methods for site cleanup (if needed) will be evaluated in a feasibility study before one is selected. The nature of the contaminants (i.e., reactivity, ability to leach) will be described and considered in this evaluation. Both the remedial investigation report and the feasibility study will be available to the public for review when they are drafted.
Based on the information reviewed, the Peter Cooper Markhams site poses an indeterminate public health hazard. Although there are no known exposures, environmental data from the site are limited. Specifically, a better understanding of groundwater conditions and possible further sampling of private wells is needed. The limited data that are currently available indicate that long-term exposure to the highest level of arsenic detected in surface water could pose a low increased cancer risk to unauthorized visitors to the site. Also, chromium in surface soil at the highest levels detected could cause allergic skin reactions in some unauthorized visitors. However, because of the remote location and current knowledge of site conditions, the potential for frequent and long-term exposure is limited and such adverse health effects are unlikely.
Agency for Toxic Substances and Disease Registry (ATSDR). 1993a. Toxicological Profile for Arsenic. Atlanta, Georgia: U.S. Department of Health and Human Services. Public Health Service.
Agency for Toxic Substances and Disease Registry (ATSDR). 1993b. Toxicological Profile for Chromium. Atlanta, Georgia: U.S. Department of Health and Human Services. Public Health Service.
Agency for Toxic Substances and Disease Registry (ATSDR). 2000. Public Health Assessment for the Peter Cooper Corporation, Village of Gowanda, Cattaraugus County.
O'Brien and Gere. 1989. Site Operations Plans, Markhams Site, Peter Cooper Corporations.
O'Brien and Gere. 1991. Feasibility Study, Peter Cooper Corporations, Markhams, New York.
US Bureau of the Census. 1991. 1990 Census of population and housing summary tape file 1B. US Department of Commerce.
US Bureau of the Census. 1992. 1990 Census of population and housing summary tape file 3A. CD-ROM. US Department of Commerce. September.
This Public Health Assessment was prepared by the New York 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 public health assessment was initiated.
Gregory V. Ulirsch
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation (DHAC), ATSDR, has reviewed this public health assessment, and concurs with its findings.
Roberta Erlwein
Chief, SPS, SSAB, DHAC, ATSDR
New York State Department of Health Authors
Dawn E. Hettrick
Assistant Sanitary Engineer
Bureau of Environmental Exposure Investigation
Donald W. R. Miles
Research Scientist
Bureau of Environmental Exposure Investigation
Sharlin Liu
Assistant Research Scientist
Bureau of Toxic Substances Assessment
Thomas B. Johnson
Research Scientist
Bureau of Toxic Substances Assessment
Agency for Toxic Substances and Disease Registry
Regional Representative
Arthur Block
Regional Operations
Office of the Assistant Administrator
Technical Project Officer
Greg Ulirsch
Technical Project Officer
Division of Health Assessment and Consultation
Superfund Site Assessment Branch
Table 1. Water Quality Standards/Guidelines and /or Public Health Assessment Comparison Values Exceeded by Contaminants Found in Groundwater at the Peter Cooper-Markhams Site
[All values in micrograms per liter (mcg/L)]
| Contaminant | Range of Detection | Water Quality Standards/Guidelines | Comparison Values* | ||||||||
| New York State | US EPA | ||||||||||
| Ground Water | Surface Water | Drinking Water | Drinking Water | ||||||||
| Cancer | Basis** | Noncancer | Basis** | ||||||||
| arsenic | 5 - 490 | 25 | 50 | 50 | 50+ | 0.023 | EPA | 1 | EPA | ||
| chromium*** | 6 - 250 | 50 | 50 | 100 | 100 | 10 | EPA | ||||
| chromium (VI) | 8 - 18 | 50 | 50 | 100 | 100 | 10 | EPA | ||||
| zinc | 10 - 80,000 | 300 | 300 | 5,000 | 5,000++ | 1,050 | EPA | ||||
* Cancer comparison values for metals are determined for a
70 kilogram adult who drinks 2 liters of water per day.
Noncancer comparison values for metals are determined for a
70 kilogram adult who drinks 2 liters of water per day. A 10% relative source
contribution is assumed for inorganic chemicals.
** EPA CPF Environmental Protection Agency cancer potency
factor.
EPA RfD Environmental Protection Agency reference dose.
*** Total chromium.
+ Under review.
++ Secondary maximum contaminant level based on aesthetic consideration.
Table 2. Water Quality Standards/Guidelines and /or Public
Health Assessment Comparison Values Exceeded by Contaminants Found in Surface
Water at the Peter Cooper-Markhams Site
[All values in micrograms per liter (mcg/L)]
| Contaminant | Range of Detection | Water Quality Standards/Guidelines | Comparison Values* | ||||||||
| New York State | US EPA | ||||||||||
| Ground Water | Surface Water | Drinking Water | Drinking Water | ||||||||
| Cancer | Basis** | Noncancer | Basis** | ||||||||
| arsenic | 5 - 104 | 25 | 50 | 50 | 50 | 30 | EPA | 1,800 | EPA RfD | ||
| chromium*** | 20 - 2840 | 50 | 50 | 100 | 100 | 18,000 | EPA RfD | ||||
* Cancer comparison values for metals are determined for a 70 kilogram adult who ingests 0.05 liters of leachate or surface water per day, 2 days a week, 3 months per year for 30 years.
Noncancer comparison values for metals are determined for a 21 kilogram child who ingests 0.05 liters of leachate or surface water per day, 2 days a week for 3 months per year.
** EPA CPF Environmental Protection Agency cancer potency factor.
EPA RfD Environmental Protection Agency reference dose.
*** Contaminant levels are for total chromium.
APPENDIX C: NEW YORK STATE DEPARTMENT OF HEALTH PROCEDURE FOR EVALUATING POTENTIAL PUBLIC HEALTH RISKS FOR CONTAMINANTS OF CONCERN
To evaluate the potential health risks from contaminants of concern associated with the Peter-Cooper-Markhams Site, the New York State Department of Health assessed the risks for cancer and noncancer health effects.
Increased cancer risks were estimated by using site-specific information on exposure levels for the contaminant of concern and interpreting them using cancer potency estimates derived for that contaminant by the US EPA or, in some cases, by the NYS DOH. The following qualitative ranking of cancer risk estimates, developed by the NYS DOH, was then used to rank the risk from very low to very high. For example, if the qualitative descriptor was "low", then the excess lifetime cancer risk from that exposure is in the range of greater than one per million to less than one per ten thousand. Other qualitative descriptors are listed below:
|
Excess Lifetime Cancer Risk
|
|
| Risk Ratio | Qualitative Descriptor |
| equal to or less than one per million | very low |
| greater than one per million to less than one per ten thousand | low |
| one per ten thousand to less than one per thousand | moderate |
| one per thousand to less than one per ten | high |
| equal to or greater than one per ten | very high |
An estimated increased excess lifetime cancer risk is not a specific estimate of expected cancers. Rather, it is a plausible upper bound estimate of the probability that a person may develop cancer sometime in his or her lifetime following exposure to that contaminant.
There is insufficient knowledge of cancer mechanisms to decide if there exists a level of exposure to a cancer-causing agent below which there is no risk of getting cancer, namely, a threshold level. Therefore, every exposure, no matter how low, to a cancer-causing compound is assumed to be associated with some increased risk. As the dose of a carcinogen decreases, the chance of developing cancer decreases, but each exposure is accompanied by some increased risk.
There is general consensus among the scientific and regulatory communities on what level of estimated excess cancer risk is acceptable. An increased lifetime cancer risk of one in one million or less is generally not considered a significant public health concern.
For noncarcinogenic health risks, the contaminant intake was estimated using exposure assumptions for the site conditions. This dose was then compared to a risk reference dose (estimated daily intake of a chemical that is likely to be without an appreciable risk of health effects) developed by the US EPA, ATSDR and/or NYS DOH. The resulting ratio was then compared to the following qualitative scale of health risk:
|
Qualitative Descriptions for Noncarcinogenic Health
Risks
|
|
| Ratio of Estimated Contaminant Intake to Risk Reference Dose | Qualitative Descriptor |
| equal to or less than the risk reference dose | minimal |
| greater than one to five times the risk reference dose | low |
| greater than five to ten times the risk reference dose | moderate |
| greater than ten times the risk reference dose | high |
Noncarcinogenic effects unlike carcinogenic effects are believed to have a threshold, that is, a dose below which adverse effects will not occur. As a result, the current practice is to identify, usually from animal toxicology experiments, a no-observed-effect-level (NOEL). This is the experimental exposure level in animals at which no adverse toxic effect is observed. The NOEL is then divided by an uncertainty factor to yield the risk reference dose. The uncertainty factor is a number which reflects the degree of uncertainty that exists when experimental animal data are extrapolated to the general human population. The magnitude of the uncertainty factor takes into consideration various factors such as sensitive subpopulations (for example, children or the elderly), extrapolation from animals to humans, and the incompleteness of available data. Thus, the risk reference dose is not expected to cause health effects because it is selected to be much lower than dosages that do not cause adverse health effects in laboratory animals.
The measure used to describe the potential for noncancer health effects to occur in an individual is expressed as a ratio of estimated contaminant intake to the risk reference dose. A ratio equal to or less than one is generally not considered a significant public health concern. If exposure to the contaminant exceeds the risk reference dose, there may be concern for potential noncancer health effects because the margin of protection is less than that afforded by the reference dose. As a rule, the greater the ratio of the estimated contaminant intake to the risk reference dose, the greater the level of concern. This level of concern depends upon an evaluation of a number of factors such as the actual potential for exposure, background exposure, and the strength of the toxicologic data.
APPENDIX D: PUBLIC HEALTH HAZARD CATEGORIES
INTERIM PUBLIC HEALTH HAZARD CATEGORIES
| CATEGORY / DEFINITION | DATA SUFFICIENCY | CRITERIA |
| 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 judgement based on critical data which 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. | 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. |
| 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 judgement based on critical data which 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. | 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 or safety hazards. |
| C. Indeterminate Public Health Hazard
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. |
This determination represents a professional judgement that critical data are missing and ATSDR has judged the data are insufficient to support a decision. This does not necessarily imply all data are incomplete; but that some additional data are required to support a decision. | The health assessor must determine, using professional judgement, 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. |
| D. No Apparent Public Health Hazard
This category is used for sites where human exposure to contaminated media may be occurring, may have occurred in the past, and/or may occur in the future, but the exposure is not expected to cause any adverse health effects. |
This determination represents a professional judgement based on critical data which ATSDR considers 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. | Evaluation of available relevant information* indicates that, under site-specific conditions of exposure, exposures to site-specific contaminants in the past, present, or future are not likely to result in any adverse impact on human health. |
| 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. |
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 |
*Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data; monitoring and management plans.
APPENDIX E: ATSDR GLOSSARY OF ENVIRONMENTAL TERMS
ATSDR defines an exposure pathway as having 5 parts:
When all 5 parts of an exposure pathway are present, it is called a Completed Exposure Pathway. Each of these 5 terms is defined in this Glossary.
