PETITIONED PUBLIC HEALTH ASSESSMENT
ANCHORAGE, JEFFERSON COUNTY, KENTUCKY
Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
Attn: Chief, Program Evaluation, Records, and Information Services Branch E-56
1600 Clifton Road NE, Atlanta, Georgia 30333
ATSDR comparison values are media-specific concentrations that are considered to be safeunder default conditions of exposure. They are used as screening values in the preliminaryidentification of site-specific "contaminants of concern". The latter term should not bemisinterpreted as an implication of "hazard". As ATSDR uses the phrase, a "contaminant ofconcern" is a chemical substance detected at the site in question and selected by the healthassessor for further evaluation of potential health effects. Generally, a chemical is selected as a"contaminant of concern" because its maximum concentration in air, water, or soil at the siteexceeds one of ATSDR's comparison values.
However, it must be emphasized that comparison values are not thresholds of toxicity.Although concentrations at, or below, the relevant comparison value may reasonably beconsidered safe, it does not automatically follow that any environmental concentration thatexceeds a comparison value would be expected to produce adverse health effects. The principlepurpose behind protective health-based standards and guidelines is to enable healthprofessionals to recognize and resolve potential public health hazards before they becomeactual public health consequences. For that reason, ATSDR's comparison values are typicallydesigned to be 1 to 3 orders of magnitude (or 10 to 1,000 times) lower than the correspondingno-effect levels (or lowest-effect levels) on which they are based. The probability that sucheffects will actually occur does not depends on environmental concentrations alone, but on aunique combination of site-specific conditions and individual lifestyle and genetic factors thataffect the route, magnitude, and duration of actual exposure.
Listed and described below are the various comparison values that ATSDR uses to select chemicals for further evaluation, as well as other non-ATSDR values that are sometimes used to put environmental concentrations into a meaningful frame of reference.
|CREG||=||Cancer Risk Evaluation Guides|
|MRL||=||Minimal Risk Level|
|EMEG||=||Environmental Media Evaluation Guides|
|IEMEG||=||Intermediate Environmental Media Evaluation Guide|
|RMEG||=||Reference Dose Media Evaluation Guide|
|RfC||=||Reference Dose Concentration|
|MCL||=||Maximum Contaminant Level|
Cancer Risk Evaluation Guides (CREGs) are estimated contaminant concentrationsexpected to cause no more than one excess cancer in a million persons exposed over a lifetime.CREGs are calculated from EPA's cancer slope factors, or cancer potency factors, using defaultvalues for exposure rates. However, neither CREGs nor cancer slope factors can be used tomake realistic predictions of cancer risk. The true risk is always unknown and may be as low aszero.
Minimal Risk Levels (MRL) are estimates of daily human exposure to a chemical (dosesexpressed in mg/kg/day) that are unlikely to be associated with any appreciable risk ofdeleterious noncancer effects over a specified duration of exposure. MRLs are calculated usingdata from human and animal studies and are reported for acute (< 14 days), intermediate (15-364 days), and chronic (> 365 days) exposures. MRLs are published in ATSDR ToxicologicalProfiles for specific chemicals.
Environmental Media Evaluation Guides (EMEGs) are concentrations that are calculatedfrom ATSDR minimal risk levels by factoring in default body weights and ingestion rates.
Intermediate Environmental Media Evaluation Guides (IEMEG) are calculated fromATSDR minimal risk levels; they factor in body weight and ingestion rates for intermediateexposures (those occurring for more than 14 days and less than 1 year).
Reference Dose Media Evaluation Guide (RMEG) is the concentration of a contaminant inair, water or soil that corresponds to EPA's RfD for that contaminant when default values forbody weight and intake rates are taken into account.
Reference Dose (RfD) is an estimate of the daily exposure to a contaminant unlikely to causenoncarcinogenic adverse health effects. Like ATSDR's MRL, EPA's RfD is a dose expressed inmg/kg/day.
Reference Concentrations (RfC) is a concentration of a substance in air that EPA considersunlikely to cause noncancer adverse health effects over a lifetime of chronic exposure.
Risk-Based Concentrations (RBC) are media-specific concentrations derived by Region III ofthe Environmental Protection Agency from RfD's, RfC's, or EPA's cancer slope factors. Theyrepresent concentrations of a contaminant in tap water, ambient air, fish, or soil (industrial orresidential) that are considered unlikely to cause adverse health effects over a lifetime ofchronic exposure. RBCs are based either on cancer ("c") or noncancer ("n") effects.
Maximum Contaminant Levels (MCLs) represent contaminant concentrations in drinkingwater that EPA deems protective of public health (considering the availability and economicsof water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of waterper day. Methodology of Evaluating Chemicals of Concern
The Agency for Toxic Substances and Disease Registry (ATSDR) has determined levels ofchemicals that can reasonably (and conservatively) be regarded as harmless, based on thescientific data the agency has collected in its toxicological profiles. The resulting comparisonvalues and health guidelines, which include ample safety factors (also known as an uncertaintyfactor) to ensure protection of sensitive populations, are used to screen contaminantconcentrations at a site and to select substances (referred to as "chemicals of concern") thatwarrant closer scrutiny. A "chemical of concern" is defined by ATSDR as any chemical that isdetected in air, water, or soil at concentrations exceeding one or more of ATSDR's comparisonvalues. (Refer to Appendix C for a more complete description of ATSDR's comparison values,health guidelines, and other values ATSDR uses to screen site contaminants.)
It is important to understand that comparison values are not thresholds of toxicity. Althoughconcentrations at, or below, the relevant comparison value may reasonably be considered safe,it does not necessarily follow that any concentration that exceeds a comparison value would beexpected to produce adverse health effects. Indeed, the principle purpose behind protectivehealth-based standards and guidelines is to enable health professionals to recognize and resolvepotential public health problems before that potential is realized. For that reason, ATSDR'scomparison values are typically designed to be 1 to 3 orders of magnitude lower than thecorresponding no-effect levels (or lowest-effect levels) on which they are based.
When screening individual contaminants, ATSDR staff compare the highest singleconcentration of a contaminant detected at the site with the lowest comparison value availablefor the most sensitive of the potentially exposed individuals (usually children or pica children). Typically the cancer risk evaluation guide (CREG) or chronic environmental media evaluationguide (EMEG) is used. This "worst-case" approach introduces a high degree of conservatisminto the analysis and often results in the selection of many contaminants as "chemicals ofconcern" that will not, upon closer scrutiny, be judged to pose any hazard to human health. Inthe interest of public health, it is prudent to use a screen that identifies many "harmless"contaminants, as opposed to one that may overlook even a single potential hazard to publichealth. The reader should keep in mind the conservativeness of this approach when interpretingATSDR's analysis of the potential health implications of site-specific exposures.
As ATSDR's most conservative comparison value, the CREG, requires special mention. ATSDR's CREG is a media-specific contaminant concentration derived from the chronic(essentially, lifetime) dose of that substance which, according to an Environmental ProtectionAgency (EPA) estimate, corresponds to a 1-in-1,000,000 cancer risk level. Note, this does notmean that exposures equivalent to the CREG are expected to cause 1 excess cancer case in1,000,000 (1x10-6) persons exposed over a lifetime. Nor does it mean that every person in apopulation of one million has a 1-in-1,000,000 risk of developing cancer from the specifiedexposure. Although commonly interpreted in this way, EPA estimates of cancer "risk" areestimates of population risk only and cannot be applied meaningfully to any individual. EPAexplicitly stated in it's 1986 Cancer Risk Assessment Guidelines that "The true risks areunknown and may be as low as zero" (EPA, 1986).
EPA, 1986. Environmental Protection Agency. Guidelines for Carcinogenic Risk Assessment. Fed. Reg., 51: 33997-33998, September 24, 1986.
Methods of Evaluation of Potential Public Health Implications
Based on available scientific data, much of which ATSDR has collected in its toxicologicalprofiles, ATSDR has determined concentrations of hazardous substances that can reasonably(and conservatively) be regarded as harmless. The resulting comparison values generallyinclude ample safety factors to ensure protection of sensitive populations. They are used toscreen contaminant concentrations at a site, and to select "contaminants of concern" thatwarrant closer scrutiny by agency health assessors and toxicologists. A "contaminant ofconcern" is defined as a substance that is detected in air, water, or soil at concentrations thatexceed one or more of ATSDR's comparison values and warrants further evaluation.
The derivation of a comparison value uses conservative exposure assumptions, resulting invalues that are much lower than exposure concentrations observed to cause adverse healtheffects. This ensures that the comparison values are protective of public health in essentially allexposure situations. Therefore, if the concentration of a substance in an exposure medium isless than the comparison value, the exposure is not of health concern and no further analysis ofthe exposure medium pathway is required.
Comparison values are conservative values, and it is important to note that concentrations ofsubstances that are higher than the comparison values will not necessarily lead to adversehealth effects. Exposure to levels of substances above their comparison values may or may notlead to adverse health effects. ATSDR's comparison values do not indicate thresholds oftoxicity, and they are not used to predict the occurrence of adverse health effects.
A level of concentration that is equal to or below a relevant comparison value is consideredsafe. However, the fact that a concentration exceeds a comparison value does not mean that theconcentration is expected to produce adverse health effects. ATSDR uses highly conservative,health-based standards and guidelines to assist health professionals in recognizing andresolving potential public health problems.
- How a chemical enters a person's blood after the chemical has been swallowed, has come into contact with the skin, or has been inhaled.
- Acute Exposure:
- Contact with a chemical that happens once or only for a limited period of time. ATSDR defines acute exposures as those that might last up to 14 days.
- Additive Effect:
- A response to a chemical mixture, or combination of substances, that might be expected if the known effects of individual chemicals, seen at specific doses, were added together.
- Adverse Health Effect:
- A change in body function or the structures of cells that can lead to disease or health problems.
- Antagonistic Effect:
- A response to a mixture of chemicals or combination of substances that is less than might be expected if the known effects of individual chemicals, seen at specific doses, were added together.
- The Agency for Toxic Substances and Disease Registry. ATSDR is a federal health agency in Atlanta, Georgia that deals with hazardous substance and waste site issues. ATSDR gives people information about harmful chemicals in their environment and tells people how to protect themselves from coming into excessive contact with chemicals.
- Background Level:
- An average, expected, or naturally occurring amount of a chemical in aspecific environment.
- The plants and animals of a region. As used in public health, the term applies especially to the indigenous plants and animals that are eaten by the local people.
- A group of diseases which occur when cells in the body become abnormal and grow, or multiply, out of control
- Any substance shown to cause tumors or cancer in experimental studies.
- See Comprehensive Environmental Response, Compensation, and Liability Act.
- Chemicals of Concern:
- A term used by ATSDR health assessors for any substance that ispresent in air, water, or soil at concentrations in excess of one or more of ATSDR'scomparison value. Chemicals of concern are evaluated further for their potential public health implications.
- Chronic Exposure:
- A contact with a substance or chemical that happens over a long period of time. ATSDR considers exposures of more than one year to be chronic.
- Community Assistance Panel (CAP):
- A group of people from the community and health and environmental agencies who work together on issues and problems at hazardous waste sites.
- Comparison Value (CVs):
- Concentrations or the amount of substances in air, water, food, and soil that are unlikely, upon exposure, to cause adverse health effects. Comparison values are used by health assessors to select those substances and environmental media (air, water, food and soil) that warrant additional evaluation.
- Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA):
- CERCLA was put into place in 1980. It is also known as Superfund. This act concerns releases of hazardous substances into the environment, and the cleanup of these substances and hazardous waste sites. ATSDR was created by this act and is responsible for looking into the health issues related to hazardous waste sites.
- The amount of a substance present in a specified amount of soil, water, air, orfood. Concentrations are commonly expressed in terms of mg or ug per kg soil, liter of water, or cubic meter of air.
- See Environmental Contaminant.
- Delayed Health Effect:
- A disease or injury that happens as a result of exposures that may have occurred far in the past.
- Dermal Contact:
- A chemical getting onto your skin. (see Route of Exposure).
- The amount of a substance to which a person may be exposed, usually on a daily basis. Dose is usually described in terms of the amount of substance(s) per body weight per day.
- Dose / Response:
- The relationship between the amount of exposure (dose) and the change in body function or health that results.
- (Exposure) Duration:
- The amount of time (days, months, years) that a person is exposed to a chemical.
- Environmental Contaminant:
- A substance (chemical) that gets into a system (person, animal, or the environment) in amounts higher than the Background Level, or what would be expected.
- Environmental Media:
- Usually refers to the air, water, and soil in which chemical of interest are found. Sometimes refers to the plants and animals that are eaten by humans.
Environmental Media is the second part of an Exposure Pathway.
- U.S. Environmental Protection Agency (EPA):
- The federal agency that develops and enforces environmental laws to protect the environment and public health.
- The study of the different factors that determine how often, in how many people, and in which people will disease occur.
- Coming into contact with a chemical substance.(For the three ways people can come in contact with substances, see Route of Exposure.)
- Exposure Assessment:
- The process of finding the ways people come in contact with chemicals, how often and how long they come in contact with chemicals, and the amounts of chemicals with which they come in contact.
- Exposure Pathway:
- A description of the way that a chemical moves from its source (where it began) to where and how people can come into contact with (or get exposed to) the chemical.
ATSDR defines an exposure pathway as having 5 parts:
- Source of Contamination,
- Environmental Media and Transport Mechanism,
- Point of Exposure,
- Route of Exposure, and,
- Receptor Population.
- Frequency (of exposure):
- How often a person is exposed to a chemical over time; for example, every day, once a week, twice a month.
- Hazardous Waste:
- Substances that have been released or thrown away into the environment and, under certain conditions, could be harmful to people who come into contact with them.
- Health Effect:
- ATSDR deals only with Adverse Health Effects (see definition in this Glossary).
- Indeterminate Public Health Hazard:
- The category is used in Public Health Assessment documents for sites where important information is lacking (missing or has not yet been gathered) about site-related chemical exposures.
- Swallowing something, as in eating or drinking. It is a way a chemical can enter your body (See Route of Exposure).
- Breathing. It is a way a chemical can enter your body (See Route of Exposure).
- Lowest Observed Adverse Effect Level. The lowest dose of a chemical in a study, or group of studies, that has caused harmful health effects in people or animals.
- See Cancer.
- Minimal Risk Level. An estimate of daily human exposure - by a specified route and length of time -- to a dose of chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects.
- The National Priorities List. (Which is part of Superfund.) A list kept by the U.S. Environmental Protection Agency (EPA) of the most serious, uncontrolled or abandoned hazardous waste sites in the country. An NPL site needs to be cleaned up or is being looked at to see if people can be exposed to chemicals from the site.
- No Observed Adverse Effect Level. The highest dose of a chemical in a study, or group of studies, that did not cause harmful health effects in people or animals.
- No Apparent Public Health Hazard:
- The category is used in ATSDR's Public Health Assessment documents for sites where exposure to site-related chemicals may have occurred in the past or is still occurring but the exposures are not at levels expected to cause adverse health effects.
- No Public Health Hazard:
- The category is used in ATSDR's Public Health Assessment documents for sites where there is evidence of an absence of exposure to site-related chemicals.
- Public Health Assessment. A report or document that looks at chemicals at a hazardous waste site and tells if people could be harmed from coming into contact with those chemicals. The PHA also tells if possible further public health actions are needed.
- A line or column of air or water containing chemicals moving from the source to areas further away. A plume can be a column or clouds of smoke from a chimney or contaminated underground water sources or contaminated surface water (such as lakes, ponds and streams).
- Point of Exposure:
- The place where someone can come into contact with a contaminated environmental medium (air, water, food or soil). For examples:
the area of a playground that has contaminated dirt, a contaminated spring used for drinking water, the location where fruits or vegetables are grown in contaminated soil, or the backyard area where someone might breathe contaminated air.
- A group of people living in a certain area; or the number of people in a certain area.
- Potentially Responsible Party. A company, government or person that is responsible for causing the pollution at a hazardous waste site. PRP's are expected to help pay for the clean up of a site.
- Public Health Assessment(s):
- See PHA.
- Public Health Hazard:
- The category is used in PHAs for sites that have certain physical features or evidence of chronic, site-related chemical exposure that could result in adverse health effects.
- Public Health Hazard Category:
- In a PHA, a category assigned to a site to indicate the degree to which the conditions at that site could pose a hazard to public health. The categories, each of which is defined in the Glossary, are:
- Urgent Public Health Hazard
- Public Health Hazard
- Indeterminate Public Health Hazard
- No Apparent Public Health Hazard
- No Public Health Hazard
- Receptor Population:
- People who live or work in the path of one or more chemicals, and who could come into contact with them (See Exposure Pathway).
- Reference Dose (RfD):
- An estimate, including built in safety factors (see safety factor), of the daily, life-time exposure of human populations to a possible hazard that is not likely to cause harm to the person.
- Route of Exposure:
- The way a chemical can get into a person's body. There are three exposure routes: breathing (also called inhalation), eating or drinking (also called ingestion), and or getting something on the skin (also called dermal contact).
- Safety Factor:
- Also called Uncertainty Factor: When, due to insufficient information, risk assessors cannot specify with certainty whether or not a given exposure will cause harm to people, they use "safety factors" and formulas in place of the missing information to enable them to conservatively estimate the amount of a chemical that is not likely to cause harm to people. Safety factors which typically range from 10 to 1000 are divided into established LOAELs or NOAELs to make them proportionately smaller (i.e., "safer")..
- The Superfund Amendments and Reauthorization Act in 1986 amended CERCLA and expanded the health-related responsibilities of ATSDR. CERCLA and SARA direct ATSDR to look into the health effects from chemical exposures at hazardous waste sites.
- Sample Size:
- The number of people, environmental samples, etc. that are needed for a health study.
- A small portion of a larger whole taken as representative of that whole. Forexample, a number of people chosen for study from a larger population (See Population) or a quantity of soil, water or air collected for analysis.
- Source (of Contamination):
- The place where a chemical comes from, such as a landfill, pond, creek, incinerator, tank, or drum. Contaminant source is the first part of an Exposure Pathway.
- Special Populations:
- People who may be more sensitive to chemical exposures because of certain factors such as age, a disease they already have, occupation, sex, or certain behaviors (like cigarette smoking). Children, pregnant women, and older people are often considered special populations.
- A branch of the math process of collecting, looking at, and summarizing data or information.
- Superfund Site:
- See NPL.
- A way to collect information or data from a group of people (population). Surveys can be done by phone, mail, or in person. ATSDR cannot do surveys of more than nine people without approval from the U.S. Department of Health and Human Services.
- Synergistic effect:
- A health effect from an exposure to more than one chemical, where one of the chemicals worsens the effect of another chemical. The combined effect of the chemicals acting together are greater than the effects of the chemicals acting by themselves.
- Poisonous. At a sufficient dose (amount), any substance or chemical can be toxic. The dose determines the toxicity of a chemical and its potential to cause illness in people exposed to it.
- The study of the harmful effects of chemicals on humans or animals.
- Abnormal growth of tissue or cells that have formed a lump or mass.
- Uncertainty Factor:
- See Safety Factor.
The Agency for Toxic Substances and Disease Registry (ATSDR) issued the public healthassessment draft for a 30-day public comment period ending January 28, 2001. A summary ofthe comments received and ATSDR responses on the Public Comment Petitioned HealthAssessment for the Bellevue Park Site, dated December 21, 2000 are summarized below:
1. Regarding the following ATSDR statement:
Several contaminants were detected at levels above ATSDR comparison values; however, no adverse health effects would be expected for adults, children, or pica children from exposure to the soil, sediment or surface water during activities such as playing and horse grooming… If soils were to be excavated or otherwise disturbed in the future, further evaluation of these media at the dump site should be evaluated to determine whether contaminants from the site could result in exposures at levels that may impact health.
The ATSDR presumes, without basis, that use of the site will be limited to those enumeratedand that the owners of the land will not disturb or excavate the contaminated material. Thisdump site is the result of illegal and unpermitted dumping on private property. The limitationsupon assumed uses of this property are inconsistent with the intended uses this petitioner hasmade known to the ATSDR. The ATSDR has been advised that all waste must be removedfrom that portion of the site belonging to the petitioner. The site will be disturbed in the futurefor that removal and the presumed limitations cited by the ATSDR place a cloud on the title ofall property owners affected by the dump site. This dump site is privately owned residentialreal property, that may be subject to specific public use easements by virtue of the previousproperty owner's recorded dedication statement.
The levels of contamination present in available data do not suggest a threat to human health.While it is not certain whether disturbing soils would expose areas of greater contamination,additional sampling when the remaining waste is removed would be necessary to determinewhat health implications, if any, would be expected. ATSDR does not make any assumptionsabout future land use, but does use default exposure scenarios to estimate risk. For example,most of ATSDR's cancer risk evaluation guides (CREGs) are based on lifetime exposure (70years) to contamination, 365 days a year. Most likely, this is not the true exposure scenario.ATSDR deems it appropriate to use these conservative guidelines as a screening for whichcontaminants to examine more closely; but these guidelines by no means represent a thresholdof toxicity or of disease. The exposure scenario must be considered carefully. In this case,ATSDR has come to the conclusion that the levels of contamination in this area, given currentenvironmental data, does not pose a threat to the health of children, adults, or animals in thecommunity. If more data become available in the future, ATSDR will examine the potentialhealth effects of exposure to the new levels of contamination detected, if requested.
The ATSDR, after recognizing that there is contamination of the dump site and there arecompleted exposure pathways for hazardous substances, concludes "no adverse health effectswould be expected". This site has Completed Exposure Pathways for hazardous waste. TheATSDR must acknowledge that adverse health effects, although not "expected," are possibleand that only remediation by removal of all contaminated media eliminates this potential foradverse health effects.
Under current site conditions and exposure scenarios, no adverse health effects are expected inthe future. EPA sampled areas that were believed to be impacted most by the dump site. Theseareas did not contain levels of contamination that have been observed in scientific literature tocause adverse health effects. Until data are present that suggest otherwise, ATSDR cannot recommend remediation.
2. Regarding the following ATSDR statement:
In 1919 the Bellevue Park Site was dedicated for use as a recreational area for the public [EPA 1998].
The ATSDR characterization of the dedication is incorrect as explained below:
The Bellevue Park Site contained a lake with an island in the center identified on the recorded(Book 2, Page 280) subdivision plat as a "park." The plat for the subdivision was prepared bythe Olmsted Bros. firm and contained the following dedication statement: DEDICATION We,the undersigned owners of the above plat of land declare the same to be the BELLVUE PARK,AN ADDITION TO ANCHORAGE, KY, and dedicate for public use, the streets, lake and parkshown thereon as far as owned or controlled by us D.C. CLARKE CARRIE R. CLARKE OWNERS".
The above statement identifies portions of the owners' land as a lake and a park and dedicatedthat land to the public, as a "lake" and a "park". The owners of the property's intent, and thatof the Olmsted Bros. firm, was "to conserve the scenery and the natural and historic objects andthe wildlife therein and to provide for the enjoyment of the same in such manner and by suchmeans as will leave them unimpaired for the enjoyment of future generations".(1)
A lake is "a large inland body of fresh or salt water"(2). The lake, dedicated to public use, servedas a retention basin for surface water. As such, it served a public use beyond mere recreation. It provided water for wildlife and aquatic flora and fauna, and served to reduce the likelihoodof downstream flooding.
Although a "park" may be characterized as providing recreational use for the public, it alsoadds intrinsic esthetic value to the entire subdivision and was intended to remain in its naturalstate(3). The park area dedicated to the public by the owners of the land was an integral part ofthe lake and their intent was "to conserve the scenery and the natural and historic objects andthe wildlife therein and to provide for the enjoyment of the same in such manner and by suchmeans as will leave them unimpaired for the enjoyment of future generations."(4)
ATSDR only provides a brief site description in its health consultations. Additionalinformation and clarifications have been noted. The paragraph in the final public healthassessment has been modified to include both lake and park.
The inference that the boundaries of the site do not extend beyond the dedicated landcontaining the lake and park is incorrect as explained below:
The unpermitted dump extended beyond the boundaries of the property dedicated in 1919 as apark and beyond the boundaries of the lake. The actual property boundaries are the subject ofprivate litigation. Although dedicated to public use, the adjacent property owners neverthelesshold title to this land by virtue of their recorded chain of title back to the Clarke's. In addition,the City of Anchorage has been ordered to remove all waste from one of the adjacent propertyowner's land.(5)
Additional information provided has been noted, additional clarifications have been added to the final document.
3. Regarding the following ATSDR statement:
The waste above the surface of the ground was removed from the site in April of 1997, but thewaste below the ground was not removed. The area was graded and seeded. A portion of theformer lake area was later used as a park and horse riding ring [EPA 1998].
The ATSDR characterization of the April 1997 removal activity and the inference that thehorse riding ring was constructed subsequently is incorrect as explained below:
A horse-riding ring was constructed in 1984(6) on top of the waste and other material previouslydumped at the site. This horse-riding ring is located on the northern portion of the site. Unpermitted and unregulated dumping continued on the southern portion of the site until 1996.
Although some waste was removed from the site in April, 1997, according to an inspection byKentucky DWM personnel on May 7, 1997, "several areas of dark, compacted solid waste,possibly asphalt fines, remained on site. Further, the Kentucky DWM informed the City ofAnchorage that all wastes from Mr. Miller's property must be removed, and receipts fordisposal must be forwarded to the Kentucky DWM by May 28, 1997 (Ref. 18). Receiptsdocumenting any subsequent removal of wastes are not available."(7)
Additional waste removal activity occurred in November 1997. Surface and subsurface wastewas removed using heavy equipment, including a track hoe. However, no testing wasperformed to insure that all hazardous and non-hazardous waste was removed. The materialremaining after this removal activity, including the organic and inorganic materials identifiedby the EPA testing was then graded and spread throughout the site. EPA Official Photographsidentify large areas of stressed vegetation, stained soil, black asphalt-type material andremnants of broken ceramic tile.(8)
Additional information provided has been noted, additional clarifications have been added to the final document.
4. Regarding the following ATSDR statement:
Children reportedly frequent the area south of the horse-riding ring when there are events or lessons, according to a February 23, 2000, memo from the petitioner to the administrator of ATSDR.
The ATSDR incorrectly infers, as explained below, that access to, and use of, the site bychildren is limited to horse-riding activities.
Access to the site is only partially restricted by wood fences.(9) The EPA observed the daughterof a local resident playing in the marsh area east of the site in 1998.(10) Children have access tothe site and play in the dirt and mud located in and around the site. No warnings advising thepublic of the presence of hazardous wastes and known or suspected carcinogens are posted atthe site.
ATSDR considered potential exposures to children via dermal, inhalation and ingestionpathways in its evaluation of public health impact of all contaminants evaluated in the surfacesoil, surface water, and sediment and found no levels of contaminants at levels that would indicate a public health hazard and the need for posting warning signs.
5. Regarding the following ATSDR Statement:
The petitioner expressed concern that the cleanup done by the city removed fill debris only, nosoil excavation was done, and soils were graded and redistributed over the landfill area priorto the EPA sampling in February 1999 for soil contaminants, and May 2000 for surface waterand sediment contamination.
The ATSDR incorrectly states that no excavation was done.
Waste removal activity in November 1997, included subsurface excavation accomplished witha track hoe and other heavy equipment.
This information has been corrected in the final health assessment.
The ATSDR characterized the material that was graded and redistributed as "soil" rather thanas waste and contaminated soil.
The remaining waste material, identified and documented by the EPA in the Revised FinalPreliminary Assessment for Bellevue Park, dated September 10, 1998, and the OfficialPhotographs attached to that report was graded and redistributed over the landfill area inNovember 1997. Subsequent EPA testing identified numerous areas containing soilcontaminated with elevated levels of organic and inorganic compounds. The EPA threshold atwhich results are considered elevated is 3 times the background level for each compound basedupon samples taken from areas adjacent to, but not included as part of the site. These elevatedsamples included materials classified as hazardous waste and known or suspected humancarcinogens.
ATSDR used the term soil in several places in the document as a general term. The soil contained contaminant levels that were below levels of health concern. See ATSDR's response to comment #11.
6. Regarding the following ATSDR statement:
The last paragraph of the Public Health Assessment Activities addresses a number of the petitioner's health concerns.
In addition to those concerns, restoration of a lake, as expressly provided for in the dedicationof the land, may be required. The ATSDR should address what measures are necessary toprotect the public health if an order requiring reclaimation and restoration of a lake is theoutcome of litigation concerning this site. In addition, the ATSDR should clarify that removalis an appropriate and essential alternative necessary "in order to prevent or mitigateexposures."(11)
ATSDR can only comment on available data. No surface water data exists for a potential lake. If the land is used for the reclamation and restoration of a lake, ATSDR will be available to re-evaluate the data to determine public health significance. ATSDR uses the most conservativescreening values to determine if existing routes of exposure pose a health hazard to children.
Contamination is present on private property. The extent of these private boundaries is thesubject of litigation. However, the ATSDR cannot assume that contaminated soil on privateproperty will remain undisturbed. In fact, the City of Anchorage has been ordered to removeall waste from one of the adjacent property owner's land.(12) The ATSDR must address thepotential for exposure and adverse health effect under all circumstances associated with the useof private property for private purposes. The ATSDR fails to address all legitimate uses thatthe private owners may make of this property. The ATSDR's apparent consideration of onlythose uses that do not disturb the land and therefore are "not expected" to result in adversehealth consequences is arbitrary and capricious and does not address legitimate uses of the landthat will result in an increased likelihood of harmful exposure to hazardous waste at the dump.
ATSDR can only comment on available data. Using existing soil data, ATSDR did not find apublic health hazard for children or for gardening. If additional data becomes available in thefuture, ATSDR will evaluate the data for public health significance, if requested.
7. Regarding the following ATSDR statement:
None of the subsurface soil samples were found to contain contaminants at levels likely to cause adverse health effects under the current exposure situations.
The ATSDR statement fails to address whether the samples demonstrate a greater potential riskfor adverse health effects resulting from exposure to the contaminated soil than the riskassociated with exposure to the soil tested to establish background levels. The word "likely" isvague and suggests that there is the possibility of adverse health effects even under the "currentexposure situations". In addition, the ATSDR, in defining CREGs, as stated a "1 x 10-6estimated excess cancer risk (a significant additional risk of developing cancer is taken to beone additional case of cancer in a population of 1 million people experiencing the exposure[emphasis added].(13) The ATSDR statement is overbroad and inconsistent with the sampleresults that exceed the CREG and RBC levels that the ATSDR identifies as "a significantadditional risk."(14)
Levels of manganese and polycyclic aromatic hydrocarbons were found to be higher than theircomparison values, in some surface soil samples, and soil lead levels were comparable to therelevant comparison values, in one sample location. However, these comparison values do notrepresent toxicity thresholds; they contain built-in safety factors and generally representconservatively safe levels of exposure. Since all levels that are below the relevant toxicitythreshold are associated with essentially the same "risk" for adverse health effects (i.e., zero.),it is not uncommon for the environmental levels of substances to exceed their respectivecomparison values and still be too low to produce adverse health effects. At Bellevue Park, achild consuming 200 mg (the default daily intake rate) of the most Mn-contaminated soil wouldingest only 0.96 mg of manganese (an essential nutrient) or about 1% of the RecommendedDaily Requirement (120 mg/day) for children ages 4-6 years. For oral exposure to PAHs, allknown effect levels for both cancerous and non-cancerous endpoints are greater than 1 mg/kgbody weight. (Most are greater than 100 mg/kg.) However, a child eating 200 mg of the soilwith the highest concentration of PAHs measured at Bellevue Park would consume only 1.3micrograms of benzo(a)pyrene which is comparable to the amount that might occur naturally ina single, charcoal-broiled, quarter pound hamburger patty. Finally, the highest concentration oflead (300 ppm) was found in a grassy area that is expected to be used only intermittently bychildren below 5 years of age. By comparison, EPA's action level for lead in residential soil is400 mg/kg; the New Jersey Department of Health recommends a maximum permissible levelof 250 ppm of lead in soil in areas without grass cover that are expected to be used repeatedlyby children below 5 years of age.
The regulatory usage of a hypothetical 1-in-a-million risk level for screening purposes shouldnot be misconstrued as implying anything at all about actual cancer incidence in exposedhumans. Neither ATSDR's CREGs nor the EPA-derived cancer slope factors on which theyare based can be used to make realistic predictions of cancer risk. As stated in EPA'sGuidelines for Carcinogen Risk Assessment, "the true value of the risk is unknown and may beas low as zero." See Appendix B of this consult for a more thorough discussion of ATSDR'sCREGs.
The ATSDR statement is limited to effects based upon "current exposure situations." The
ATSDR must address all exposure situations associated with the unrestricted use of those portions of the site that are private property now or that revert to private property by adjudication. In addition, exposure resulting from reclaimation and restoration of a lake, as provided in the original property owners' dedication of the land, should be addressed. "Removing the contaminated material" is clearly an appropriate alternative that may be essential "in order to prevent or mitigate exposures."(15)
ATSDR used all available environmental data to determine if adverse health effects werepossible under current exposure situations. ATSDR can not base a health call on possiblefuture scenarios since these are unknown and current data do not indicate a public health concern.
8. Regarding the following ATSDR statement:
In the surface soil samples, levels of manganese and polycyclic aromatic hydrocarbons (PAHs)were found to be higher than ATSDR comparison values; these are discussed in the following sections.
The ATSDR fails to address the potential adverse health effect of the lead identified at the ATSDR Comparison Value of 300 mg/kg in the EPA sample identified as BP-03-SS.
At the request of the petitioner, ATSDR discussed residential soil lead levels in the final health consultation/final health assessment.
9. Regarding the following ATSDR statement:
Few adverse health effects clearly attributable to PAHs have ever been demonstrated inhumans, and there a no comparison values for PAHs based on non-carcinogenic effect. … thecancer-category Risk Based Concentration (RBCs) calculated by EPA Region III were used forthese PAHs in Table 1. …There is no evidence that either dermal or oral exposure to PAHs causes cancer in humans [ATSDR 1995].
The ATSDR analysis is contrary to the conclusions and guidance contained in The ToxicologicHazard of Superfund Hazardous Waste Sites, Barry L. Johnson and Christopher T. DeRosa,Agency for Toxic Substances and Disease Registry, Public Health Service, Atlanta, Georgia,U.S.A., 30333.(16)
That report includes benzo(b)pyrene as one of the substances identified as Completed ExposurePathway Priority Substances (CEPPS). Benzo(a)pyrene is a chemical identified in that reportas "a known or suspected carcinogen."(17) The EPA also identifies benzo(a)pyrene as a humancarcinogen and has established the RBC levels based upon a lifetime cancer risk of 1 in onemillion.(18) "Regardless of how one defines "environmental factors," prudent public healthpolicy advocates the prevention of exposure to carcinogenic substances…"(19)
Furthermore, "no CEPPS is without any systemic toxicity if exposure levels are very high. This suggests that these 30 CEPPS should, in a precautionary sense, be considered aspotentially harmful to populations residing near sites with completed exposure pathways untilevidence to the contrary…. Prudent public policy dictates that human exposures be prevented,and site remediation is consistent with reducing or preventing human exposure."(20)
Nothing in the cited guidance should be construed to mean that PAHs are toxic at any and alldoses, no matter how small. Just the opposite is true. Normally innocuous substances will betoxic, if the levels are high enough, and even highly toxic substances will be innocuous, if thelevels are low enough. The institutional derivation of safe levels of exposure for non-carcinogens are predicated on the toxicological maxim that "the dose is the poison." Evencarcinogens have thresholds. However, due to the difficulties associated with measuring the thresholds of effects that have long latency periods, it is more convenient to assume theabsence of such thresholds, for regulatory purposes, and linearly extrapolate from high doseeffects in animals (or, less often, in humans) to an arbitrarily established "negligible risk" levelin humans . This negligible risk level (e.g., "1-in-a-million") should not, however, be mistakenfor a realistic prediction of the true risk, for the latter is unknown and may be as low as zero(EPA, 1986; 2000). None of the contaminants detected at the Bellevue Park site were presentat levels that ATSDR believes could produce adverse health effects in humans under site-specific conditions of exposure.
10. Regarding the following ATSDR statement:
All of these comparison values are based on extrapolations from high-dose animalexperiments…These animal experiments are of limited relevance to human exposure scenarios.
The ATSDR discussion of the methodology for animal testing seems to trivialize the EPAidentification of the compounds discussed as known or suspected human carcinogens. Certainly, the ATSDR is not recommending human exposure to the elevated levels of theknown or suspected carcinogenic compounds identified with completed exposure pathways atthe Bellevue Park site. Furthermore, the conclusion that there is "no evidence that eitherdermal or oral exposure to PAHs causes cancer in humans" is inconsistent with the EPA andATSDR guidance.(21)
The cited statements from the consult are not "inconsistent with the EPA and ATSDRguidance". By putting all the available data into an accurate and meaningful public healthperspective, the cited statements are in conformance with ATSDR guidance. These statementsshould not be construed as "trivializing" EPA's carcinogen classification scheme. EPA'sidentification of a compound as a known or suspected carcinogens means only that high dosesof that compound can cause cancer, i.e., under certain conditions and in certain species. Suchclassifications are irrelevant to the question of whether or not low environmental levels of thesame substance will cause cancer in a human being. The latter question can only be addressedby evaluating the best and most relevant medical and toxicologic data available. Thus, ratherthan "trivializing" EPA's carcinogen classification scheme, the cited statements from theconsult attempt to put such classifications into their proper public health perspective. (See also the response to the previous comment.)
11. Regarding the following ATSDR statement:
The levels of PAHs detected in even the most highly contaminated soils at Bellevue Park arebelow levels known to produce adverse health effects in humans or animals.
The ATSDR statement is overreaching and does not properly characterize the potential healthhazard at the Bellevue Park site as explained below:
The ATSDR cannot determine what levels of PAHs are present in the "most highlycontaminated soils." The ATSDR analysis can only evaluate the levels of contaminationavailable based upon the EPA sampling. That sampling cannot be assumed to represent the"most highly contaminated soils." There is no evidence to suggest that EPA sampling has yetidentified the areas of the site containing the highest levels of organic or inorganiccontamination. Because of the unpermitted, and unregulated dumping at the site, combinedwith the subsequent incomplete waste removal, excavation and random grading, the EPA datashould be interpreted as indicative of the mean contamination levels at the site. Therefore, it isreasonable to conclude that much higher levels of PAHs and other contaminants are present atthis site and have completed exposure pathways.
The removal activities accomplished in April of 1997 and the subsequent excavation andgrading in November 1997 cannot be assumed remediation of the most contaminated areas ofthe site.
ATSDR is only able to make conclusions from existing sampling data. The data available toATSDR were not the result of a random sampling event. EPA selected sampling sites with theintention of identifying the most contaminated areas. If EPA conducts further sampling inresponse to changed site conditions, ATSDR is available to evaluate the data for public health significance.
12. Regarding the following ATSDR statement:
If a child eats 200 mg of the most contaminated soil at Bellevue Park every day, the resultingdaily intake of BaP TEQs would be only 0.002mg (2ug) which is comparable to the amount ofBaP that might be found in a grilled quarter-pound hamburger. …Therefore, ATSDRconcludes that no adverse health effects, including cancer, would be expected to result from exposure to soils at Bellevue Park containing PAHs at the maximum levels detected.
The ATSDR assumption that the EPA sampling has identified "the most contaminated soil atBellevue Park" is without foundation. The ATSDR concludes, without explanation, that the1997 excavation, grading and removal activities accomplished the removal of all wastescontaining higher levels of PAHs than detected by the limited EPA sampling.
See response to Public Comment # 11.
The ATSDR analysis of PAHs is based upon TEQs without explanation or foundation. On itsface, this methodology appears inappropriate for evaluation of the compounds detected.
It is true that TEFs for PAHs do not provide a truly accurate means of predicting any healthrisks that these compounds may pose to human beings under site-specific conditions ofexposure. They are decidedly conservative and have limited relevance to human biology - mostare based on mouse skin tumors generated in skin-painting experiments - and even lessrelevance to plausible scenarios of human exposure. Depending on the TEF values used, thespecific congeners included in the analysis, the estimated intake rates used, and otherassumptions, the end result of the analysis could have been somewhat higher or somewhatlower. In either case, the conclusion would have been the same, i.e., that, based on all datacurrently available, exposures to PAHs in soils at Bellevue Park are not expected to be of anypublic health significance. To eliminate any confusion that may be caused by the application ofTEF/TEQ methodology to PAHs at this site, the cited text in the consult will be altered to read:"A child eating 200 mg of the most PAH-contaminated soil at Bellevue Park (sample BP-04-SS) would consume an amount of benzo(a)pyrene (i.e., 1.3 millionths of a gram) comparableto that which might occur naturally in a single, charcoal-broiled, quarter pound hamburgerpatty.
The reference to consumption of a grilled quarter-pound hamburger as being equivalent to theexposure to known or suspected human carcinogens detected at levels exceeding EPA RBClevels in the soils at Bellevue Park, is flippant and disregards EPA and ATSDR guidance. TheATSDR statement seems to suggest that consumption of the contaminated soil at this site, by achild, is equivalent to eating fast food. The ATSDR has identified benzo(a)pyrene as a CEPPSand recommends that "regardless of how one defines "environmental factors," prudent publichealth policy advocates the prevention of exposure to carcinogenic substances."(22)
The hamburger analogy was an effort at effective risk communication, and was not meant to be"flippant", or to be read as disregarding EPA and ATSDR guidance. The intention was to putpotential exposures to PAH-contaminated soil at Bellevue Park into a meaningful perspectiveby comparing the latter to something in common experience. The analogy was provided insupport of the conclusion that immediately followed, i.e., that "ATSDR concludes that noadverse health effects, including cancer, would be expected to result from exposure to soils at Bellevue Park containing PAHs at the maximum levels detected."
13. Regarding the following ATSDR statement:
In one surface sample at Bellevue Park, manganese exceeded ATSDR's soil reference dosemedia evaluation guide (RMEG) for children (3000ppm), …Assuming that a child eats 200 mgof the most contaminated soil…Therefore, considering the low concentrations involved, andthe conservatism of soil RMEGs for children, ATSDR does not consider manganese or anyother metal detected in soil in the Bellevue Park Area to pose a threat to public health.
The ATSDR first acknowledges the sample exceeds the RMEG level for children and thendismissed the relevance of that screening level. The ATSDR also concludes, withoutexplanation, that the EPA sampling reflects "the most contaminated soil" at Bellevue Park. Asexplained previously, this conclusion is not supported by the history of the site, or by anyreasonable evaluation of the limitations of the sampling data available.
The purpose of screening values is to identify contaminants for further evaluation; they cannot,by themselves, be used to identify public health hazards. The latter can only be accomplishedby evaluating the best medical and toxicologic data for the specific contaminant in the contextof site-specific exposures. While screening values are sometimes confused with thresholds oftoxicity, the government agencies that derive and use them, including EPA, intentionallydesigned their comparison values to be lower than actual toxicity thresholds (typically 1 to 3orders of magnitude lower) and use them only to facilitate early, preliminary decisions in theoverall risk management process. ATSDR uses them to determine whether a given site-specific contaminant warrants the further evaluation described above. For clarification, anappendix describing comparison values and their use by ATSDR will be added to the finaldocument.
The ATSDR discussion of manganese seems to conclude that ingestion of manganese atharmful levels will "irritate the G.I. tract and induce vomiting" therefore preventing "systemictoxicity" and effectively negate the relevance of the RMEG levels for screening.(23) Irritation ofchildren's G.I. tract and vomiting caused by ingestion of soils containing elevated levels ofmanganese certainly seems to be a public health concern.
The cited statement concerning the tendency for very high levels of manganese to inducevomiting was included solely as a possible explanation for the fact that reports of systemictoxicity due to excessive oral exposure to manganese are so rare. It is highly unlikely that achild could get its daily requirement of manganese by eating dirt in Bellevue Park, much lessingest the quantities of manganese required to produce gastrointestinal irritation. As stated inthe consult, "ATSDR does not consider manganese or any other metal detected in soil in theBellevue Park area to pose a threat to public health." See response to previous comment for clarification of "the relevance of the RMEG."
14. Regarding the following ATSDR Statement:
Because the area does have a grass cover and is expected to be used only intermittently by children below 5 years of age, the level of lead in the soil is not expected to pose a threat to public health.
The ATSDR presumes, without any basis, that the land will remain covered with grass.Furthermore, although the ATSDR evaluated the ingestion of contaminated soils for othercontaminants, the ATSDR arbitrarily and capriciously fails to apply the same analysis for leadcontaminated soils. The ATSDR fails to give a fair consideration of pica child exposure risks.Furthermore, if this land is used for its intended purpose i.e. as an extension of the existing drylot for horses on the petitioner's property, the grass cover will be eliminated. The ATSDReffectively limits the use of this land by the private property owner.
ATSDR did not apply the same methodology to lead analysis for exposure to detectedcontaminant levels because the same methodology is not currently available. ATSDR does nothave comparison values established for lead exposure in soils. In this case, as a default,ATSDR used the EPA risk-based screening levels for lead exposure. This screening level isbased on ingestion and inhalation exposure with dermal exposure. It does not differentiatebetween pica child, child, and adult exposure levels. Screening levels are chemicalconcentrations that correspond to fixed levels of risk (i.e., either a one-in-one million [10-6]lifetime cancer risk or a non-carcinogenic hazard quotient of one, whichever occurs at a lowerconcentration) in soil, air, and water. In most cases, where a substance causes both cancer andnon-cancer or systemic effects, the 10-6 cancer risk will result in a more stringent criterion.
Even if there was no grass cover on the property, exposure to dangerous levels of lead via soilinhalation and ingestion is still highly unlikely. ATSDR (1995) finalized a multisite lead andcadmium study that determined that children (6 months to 14 years old) exposed to leadconcentrations in their residential yards did not show any increases at all of blood lead levelsbelow 500 mg/kg. Children exhibiting pica behavior are usually toddlers, and usually exhibitthe behavior for a very short period of time (six month or less). Toddlers are unlikely to play inthis area unsupervised by parents, and are equally unlikely to be exposed for a long enoughduration and eat enough soil to result in elevated blood levels.
The ATSDR presumes, without any basis, that this property will be used "only intermittently"by children below 5 years of age. This is not a reasonable assumption regarding privately heldproperty. Furthermore, the ATSDR does not define what "intermittently" means. The clearimplication is that if a child under 5 years of age uses the property more than "intermittently"there is a health threat. The obvious question is what constitutes "intermittent" use.
This statement is reworded for clarification in the final health assessment.
15. Regarding the following ATSDR statement:
On the basis of animal studies, ATSDR does not believe that the combined effect of all these contaminants is likely to be of public health concern. …Based on the evaluation of the available site-specific data and selected exposure scenarios, ATSDR concluded that none of the surface soil, sediment or surface water samples from the Bellevue Park Site contained organic or inorganic compounds at levels that would pose a health hazard to anyone exposed to these compounds through incidental ingestion of surface soils, sediment or surface water.
The ATSDR conclusion is inconsistent with EPA and ATSDR guidance and policy asdescribed below:
"The relatively sparse data on cancer rates in populations residing near hazardous wastesites is somewhat surprising, given that analysis of sites with completed exposurepathways shows the presence of several known or suspect human carcinogens. It ispossible that the generally low exposures that characterize population in completedexposure pathways account for only a small increase in cancer rates, and thereforewould be difficult to detect in cancer surveillance systems. It is also possible thatsufficient time has not elapsed between the release of carcinogens into completedexposure pathways to cause an elevation in cancer rates. Regardless, the presence ofsignificant numbers of carcinogens in completed exposure pathways is a concern forprotecting the public's health.(24) Furthermore, "prudent public policy dictates thathuman exposures be prevented, and site remediation is consistent with reducing orpreventing human exposure".(25)
The ATSDR evaluation of the Bellevue Park Site completely disregards any increasedpotential cancer risk associated with exposure to the known or suspected carcinogenspresent at levels exceeding the EPA RBC and the ATSDR CREG levels. Although therisks associated with this site (based upon the limited data available) may not be asgreat as sites with higher identified contamination levels, the presence of thesecompounds should be a concern for protecting the public's health.
A more reasonable evaluation is a comparison of the risks associated with the BellevuePark site, and the contaminated soils present, to land that has not been contaminated. The use of this site for its lawful and dedicated purpose, i.e., as a lake and a park,surrounded by private residential property, as opposed to an unpermitted andunregulated dump requires this comparison. In fact, the reclaimation of this land andrestoration of a lake and park is entirely consistent with "reducing or preventing human exposure."(26)
Table 1 of the health assessment lists all the site-specific contaminants that were detected inmaximum concentrations that exceeded the relevant comparison values, including CREGs andcancer-based RBCs. The only compounds fitting that description were PAHs. As statedearlier, the maximum concentration of the PAH generally regarded as being the most toxicwould lead to estimated exposures comparable to those associated with eating a single, quarter-pound, charcoal-broiled hamburger patty. PAHs are natural substances that are ubiquitous inthe environment and always have been. They are rapidly metabolized and excreted. Onlyprolonged exposure to high levels of complex mixtures of PAHs (e.g., in tobacco smoke, cokeoven emissions, and roofing tar) have been linked to demonstrable health effects in humans. No adverse health effects have been observed, cancerous or non-cancerous, in animals orhumans, with oral exposures of 1 mg/kg body weight or less. The cancer "risks" associatedwith low exposures like those potentially occurring at Bellevue Park are not real (i.e., actuarial)risks based on any human or animal data. (Such data simply do not exist for lowenvironmental exposures.) They are, instead, theoretical risks that reflect the conservativeassumptions on which they are based more than they do any true carcinogenic risks to humans. In fact, as stated in EPA's Guidelines for Carcinogen Risk Assessment (1986, 2000), "the truerisk is unknown and may be as low as zero." That is why ATSDR, EPA, and all othergovernment agencies that create cancer-based comparison values use them exclusively asconservative screening values in the early stages of the risk management process. Dependingon the specific mission and responsibilities of the agency in question, different decisions willbe triggered when a comparison value is exceeded. At ATSDR, a non-regulatory public healthinformation agency, it triggers the decision to further evaluate the contaminant in question todetermine its potential for producing adverse health effects in people who may be exposed under site-specific conditions. (See also the response to Comment 13/1.)
16. Regarding the following ATSDR statement:
Adverse health effects are not expected from exposure to contaminant levels found in thesurface soil, sediment or surface water at the dump site. The potential for contactingcontaminants at concentrations associated with adverse health effects is limited. It is thereforedoubtful that exposure to surface soil, sediment or surface water - either through ingestion, inhalation or dermal contact - would present a public health hazard to humans.
The ATSDR has deleted the reference to "residential sites" contained in the Petitioned HealthConsultation and now characterizes the entire area as the "dump site." This characterizationdisregards, without basis, the legal status of the site as private residential property, portions ofwhich may be subject to a dedication of this private property to public use.
Contrary to previous statements essentially ruling out all risk resulting from exposure tocontaminated soils at the Bellevue Park Site, the ATSDR appears to suggest here some lowlevel of probability that adverse health consequences may result from exposure to these soils. Again, if exposure to the contamination present at the Bellevue Park Site is expected to resultin any increased potential for harm to private property owners or to the public, when comparedto exposure to uncontaminated soil, the ATSDR should clearly state that there is someincreased risk.
Notwithstanding the discussions of the various compounds at this site, the ATSDR by usingwords such as "not expected", "potential," "limited" and "doubtful" seems to infer that there is,in fact, the potential for harmful health consequences from long-term exposure to thecontaminated soils at the Bellevue Park Site.
See response to Comment # 15 on the previous page.
17. Regarding the following ATSDR Statement:
However, if concern exists regarding health effects from possible exposure for horses, a veterinarian should be contacted for more information.
The petitioner provided the ATSDR with the conclusions of Dr. Lenn Harrison, Director ofPathology, Maxwell H. Gluck Equine Research Center, University of Kentucky. Dr. Harrisonrecommended that the site not be used for pasture because of the multiple contaminants presentin the soil. The ATSDR completely disregards the information provided.
ATSDR toxicologists have analyzed the levels of contamination present and have determinedthat the levels measured are not likely to cause health effects in humans. ATSDR made therecommendation above as a referral for a concerned citizen. The health of animals or pets isoutside ATSDR's purview of work, and is not addressed here. However, many of the health-based guidelines applied to levels detected here are derived from both animal and humanstudies. ATSDR does not expect the levels reported here to result in any adverse effects inhorses pastured on the property, however, the residents in the area may still prefer to consult with their local veterinarian.
18. Regarding the following ATSDR statement:
Based on the available environmental sampling data for surface soil, subsurface soil, sediment and surface water, ATSDR categorizes the Bellevue Park Site as posing No Apparent Public Health Hazard.
Classification of the Bellevue Park Site a Public Health Hazard will require a determination bythe ATSDR that the site poses a public health hazard as the result of long-term exposures tohazardous substances. The disturbance of the site during the 1997 excavation, grading andremoval activities, combined with the numerous organic, inorganic, hazardous and othercompounds present at levels significantly exceeding the background levels, indicates thatcontaminated soils have been spread throughout the site. Because of the limited testing dataavailable, and the very real potential for soils in the area to contain substantially higher levelsof these, or other contaminants, classification of the site as a Public Health Hazard cannot beeliminated at this time.
In any event, the limited data is insufficient for the ATSDR to definitively state that "currentsoil contamination is unlikely to cause any adverse health effects." In fact, given the history ofthe site, the intended and dedicated use of the land and the unknown long-term exposureconsequences, a recommendation by the ATSDR that "removing the contaminated material"(27)is prudent and will, consistent with ATSDR policy, prevent public exposure to the carcinogenic substances identified at this site is appropriate.
All of the information available to ATSDR supports the conclusion that "current soilcontamination is unlikely to cause any adverse health effects." When new data to the contrarybecome available, or levels of contamination or site-specific conditions of exposure change,ATSDR's conclusion will be amended accordingly. ATSDR had recommended that more databe collected so that the agency might further evaluate the public health implications ofcontaminants at this site.
These data have been provided to ATSDR by EPA since the release of the draft healthconsultation, and are evaluated and discussed in this health assessment, which was released forpublic comment on December 29, 2000. After evaluation of all the data available, ATSDRclassified the site as a "no apparent public health hazard". However, if additional data becomeavailable or site conditions change, ATSDR will be available to review and evaluate that data under for those specific exposure scenarios.
1. National Park Service website: http://www.nps.gov/frla/, Frederick Law Olmsted National Historic Site, In Brief, quoting F. L. Olmsted, Jr.
2. Second American Edition, The American Heritage Dictionary, page 711
3. Second American Edition, The American Heritage Dictionary, page 903, Park: 1 c. "a tract of land kept in its natural state"
4. National Park Service website: http://www.nps.gov/frla/, Frederick Law Olmsted National Historic Site, In Brief, quoting F. L. Olmsted, Jr.
5. EPA Revised Final Preliminary Assessment Report, page 6. "Further, the Kentucky DWM informed the City of Anchorage that all wastes from Mr. Miller's property must be removed."
6. Official Minutes, Long Run Pony Club Annual Sponsor's Meeting, Jane MacDonald, October 22, 1984.
7. EPA Revised Final Preliminary Assessment Report, September 10, 1998, page 6.
8. Id. Description of Official Photographs # 2, 3, 4, 6, and 11, page numbers A-2, A-3, A-4, A-6 and A-11.
9. Id. Description of Official Photograph # 9, page A-9.
10. Id. Description of Official Photograph # 10, page A-10.
11. Petitioned Health Consultation, Public Comment, Bellevue Park, Anchorage, Jefferson County, Kentucky, July 19, 2000, Health consultation: A Note of Explanation.
12. EPA Revised Final Preliminary Assessment Report, page 6. "Further, the Kentucky DWM informed the City of Anchorage that all wastes from Mr. Miller's property must be removed."
13. ATSDR Public Health Assessment, Lower Ecorse Creek Dump, Wyandotte, Wayne County, Michigan, Appendix B. List of Tables, footnotes to Table 1
15. Petitioned Health Consultation, Public Comment, Bellevue Park, Anchorage, Jefferson County, Kentucky, July 19, 2000, Health consultation: A Note of Explanation.
16. The Toxicologic Hazard of Superfund Hazardous Waste Sites, Barry L. Johnson and Christopher T. DeRosa, Agency for Toxic Substances and Disease Registry, Public Health Service, Reviews on Environmental Health, Freund Publishing House Ltd., 1997, Volume 12, No. 4, pp 235-251, 1997, http://www.atsdr.cdc.gov/toxhazsf.html
17. Id. Table 2
18. United States Environmental Protection Agency, Region III, Contents, Uses, and Limitations of the RBC Table, Jennifer Hubbard, April 13, 2000.
19. The Toxicologic Hazard of Superfund Hazardous Waste Sites, Johnson and DeRosa, Reviews on Environmental Health, Freund Publishing House Ltd., 1997, Volume 12, No. 4, pp 235-251, 1997.
23. Petitioned Health Consultation, Public Comment, Bellevue Park, Anchorage, Jefferson County, Kentucky, July 19, 2000, page 6.
24. The Toxicologic Hazard of Superfund Hazardous Waste Sites, Johnson and DeRosa, Reviews on Environmental Health, Freund Publishing House Ltd., 1997, Volume 12, No. 4, pp 235-251, 1997.
27. Petitioned Health Consultation, Public Comment, Bellevue Park, Anchorage, Jefferson County, Kentucky, July 19, 2000, Health consultation: A Note of Explanation.