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HEALTH CONSULTATION

OLEAN WELL FIELD
OLEAN, CATTARAUGUS COUNTY, NEW YORK


APPENDIX A

Figure
Figure 1



APPENDIX B

New York State Department of Health
Procedure for Evaluating Potential Health Risks
for Contaminants of Concern

To evaluate the potential health risks from contaminants of concern associated with the Olean Well Field 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 in a million very low
greater than one in a million to less
than one in ten thousand
low
one in ten thousand to less than one
in a thousand
moderate
one in a thousand to less than one
in ten
high
equal to or greater than one in 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 considered an insignificant increase in cancer risk.

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
reference dose or minimal
risk level

minimal

greater than one to five times
the reference dose or minimal
risk level

low

greater than five to ten times
the reference dose or minimal
risk level

moderate

greater than ten times the
reference dose or minimal risk
level

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. 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. A ratio equal to or less than one is generally considered an insignificant (minimal) increase in risk.


APPENDIX C

ATSDR Public Health Hazard Categories

Category Definition Criteria
A. Urgent public health hazard This category is used for sites that pose an urgent public health hazard as the result of short-term exposures to hazardous substances.
  • evidence exists that exposures have occurred, are occurring, or are likely to occur in the future AND
  • estimated exposures are to a substance(s) at concentrations in the environment that, upon short-term exposures, can cause adverse health effects to any segment of the receptor population AND/OR
  • community-specific health outcome data indicate that the site has had an adverse impact on human health that requires rapid intervention AND/OR
  • physical hazards at the site pose an imminent risk of physical injury
  • B. Public health hazard This category is used for sites that pose a public health hazard as the result of long-term exposures to hazardous substances.
  • evidence exists that exposures have occurred, are occurring, or are likely to occur in the future AND
  • estimated exposures are to a substance(s) at concentrations in the environment that, upon long-term exposures, can cause adverse health effects to any segment of the receptor population AND/OR
  • community-specific health outcome data indicate that the site has had an adverse impact on human health that requires intervention
  • C. Indeterminate public health hazard This category is used for sites with incomplete information.
  • limited available data do not indicate that humans are being or have been exposed to levels of contamination that would be expected to cause adverse health effects; data or information are not available for all environmental media to which humans may be exposed AND
  • there are insufficient or no community-specific health outcome data to indicate that the site has had an adverse impact on human health
  • D. No apparent public health hazard This category is used for sites where human exposure to contaminated media is occurring or has occurred in the past, but the exposure is below a level of health hazard.
  • exposures do not exceed an ATSDR chronic MRL or other comparable value AND
  • data are available for all environmental media to which humans are being exposed AND
  • there are no community-specific health outcome data to indicate that the site has had an adverse impact on human health
  • E. No public health hazard This category is used for sites that do not pose a public health hazard.
  • no evidence of current or past human exposure to contaminated media AND
  • future exposures to contaminated media are not likely to occur AND
  • there are no community-specific health outcome data to indicate that the site has had an adverse impact on human health

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