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PUBLIC HEALTH ASSESSMENT

FEDERAL CREOSOTE
MANVILLE, SOMERSET COUNTY, NEW JERSEY


DISCUSSION

This section lists the contaminants found at the Federal Creosote site, discusses the likelihood of human exposure to those contaminants ("exposure pathways"), and reviews the possible health effects from exposure to these contaminants. Finally, community health concerns not covered elsewhere are noted and addressed.

A. Contaminants of Concern

Coal tar creosote is a complex mixture of over 300 identified compounds. There may be 10,000 other chemicals present in trace amounts in the mixture. Coal tar creosote is distilled from coal tar, which is derived from coal. The source of the coal (which can contain numerous and varying organic and inorganic compounds) and the distillation methods used to produce coal tar creosote are the reasons that there are so many different compounds at different concentrations that can be found in any individual batch of product. Generally, at least 75% of coal tar creosote consists of polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). The other major constituents of coal tar creosote are tar acids (phenols, cresols, and xylenols) and tar bases (pyridine and lutidine derivatives).

Health guidelines are developed for individual contaminants commonly found at hazardous waste sites. When exposure (or dose) is below a health guideline level, then adverse health effects are unlikely to occur. Examples of health guidelines are the ATSDR's Minimal Risk Level (MRL) and the USEPA's Reference Dose (RfD). For compounds that can cause cancer, ATSDR has developed a Cancer Risk Evaluation Guide (CREG). The CREG is the amount of a contaminant in the environmental medium of concern that is associated with a one in one million excess cancer risk (that is, one additional cancer in one million exposed people). Environmental Media Evaluation Guides (EMEG) have also been developed by ATSDR to represent a level of contamination in a specific medium (air, drinking water, or soil) that is not likely to pose a threat to health.

MRLs are developed for each type of exposure, such as acute (up to 14 days), intermediate (15 to 364 days), and chronic (365 days and greater). ATSDR presents these MRL's in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status.

Because there are so many possible combinations of compounds, there is no MRL for creosote. There are no MRLs for acute, intermediate or chronic exposure, whether through ingestion, inhalation, or dermal contact, for any of the PAHs except for intermediate ingestion exposures to four of the PAHs.

Compounds detected in samples at levels above health-based guidelines will be discussed individually. However, the cumulative or synergistic effects of mixtures of contaminants may increase their public health significance. Additionally, individual or mixtures of contaminants may have the ability to produce greater adverse health effects in children as compared to adults. This situation depends upon the specific chemical being ingested or inhaled, what happens to the chemical once it enters the body, and its toxicity.

Since there is no standard against which coal tar creosote found at this site can be measured, some of the compounds expected to be in the mixture were measured instead, as an indirect way to identify the presence of coal tar creosote. The USEPA, in several sampling rounds beginning in 1997, detected the following components of coal tar creosote and other contaminants likely to be found at a former wood preservative site:

Residential Surface Soil (0 - 6 inches)

Contaminant Range Measured Comparison Value Comment
Total PAHs 1 65 to 758 mg/kg
(six properties with highest levels)
NA Sampling event October 1997

1 sample each from approximately 25 properties

non-detect to 33 mg/kg (remaining properties sampled)
Lead < 180 - 4,780 mg/kg NA Sampling event Spring 1998

10 - 12 samples from each of 133 residences

Arsenic < 12 - 16 mg/kg 0.6 (EMEG for pica child)
Benzo[a]pyrene equivalents 2 0.03 - 43 mg/kg 0.1 (CREG) (for benzo[a]pyene)
1 Total PAHs is defined as the sum of each individual PAH measured in the sample
2 Benzo[a]pyrene equivalent defined: Seven of the PAHs are known to cause cancer in animals. The most potent carcinogen of these seven is benzo[a]pyrene. The toxicity of each of the other six PAHs is compared to that of benzo[a]pyrene, giving a toxicity-equivalent factor. This factor describes how carcinogenic it is relative to benzo[a]pyrene. In calculating benzo[a]pyrene-equivalent concentrations, the concentration of each PAH is multiplied by its toxicity equivalent factor. The resulting weighted concentrations are summed to calculate the benzo[a]pyrene-equivalent carcinogenic PAH value.

Subsurface soil

The Borough of Manville conducted a preliminary assessment of contamination in December 1996 and March 1997. Soil boring samples were taken adjacent to a storm sewer and at one residence. Two samples were taken from the residential property. PAHs were detected in all three samples; total xylenes and benzene were detected in one of the residential samples at levels above NJDEP residential soil clean-up levels.

The USEPA has completed more extensive sub-surface soil sampling to delineate the site and determine the location of the creosote. They have identified 28 properties that lie above the highly contaminated canals and lagoons, and an additional 54 properties with lower levels of creosote contaminants in soil. All of the 28 properties on canals and lagoons will have the source material removed. Seventeen of those properties will require permanent relocation of the residents and demolition of the houses prior to the removal of contaminated sub-surface soil and source material.

The 54 properties with lower levels of contaminants in sub-surface soil will undergo remediation, which will include removal of soil to depths of 2 to 10 feet, and replacement with clean fill. At 6 of the 54 properties, soil contamination extends below 10 feet, which is the maximum depth that EPA will remediate. However, because NJDEP regulations require cleanup to bedrock, EPA is proposing to purchase those properties, because the properties will need to have deed restrictions put in place.

Indoor Air

The USEPA conducted air sampling in 126 homes in the development in 1997. The New Jersey Department of Environmental Protection administered a questionnaire to the residents of these homes. The purpose of the investigation was to determine if volatile organic compounds and polycyclic aromatic hydrocarbons from the coal tar creosote were affecting indoor air quality. The questionnaire was designed to rule out contaminants which might be a result of household and other consumer products used by the residents. The USEPA found the following:

  • benzene was not detected at levels that would be expected from a creosote site;
  • elevated levels of naphthalene were found in several homes; however, these levels were traced to the residents' use of mothballs or moth flakes;
  • several residences had elevated levels of various volatile organic compounds, which were found to be a result of the use and/or in-home storage of solvents, polishes, paint thinners, degreasers, insecticides, fuel components, and cleaners;
  • natural gas leaks were detected in nearly 20% of the homes tested.

Groundwater

Monitoring wells located on the site indicate that groundwater is contaminated with components of creosote. The USEPA has or will install approximately 50 monitoring wells on- and off-site to delineate the full nature and extent of the plume. Analyses of these data are expected to be completed in the autumn of 2000.

B. Pathways of Exposure

Exposure occurs when a completed exposure pathway exists. An exposure pathway is the route a contaminant takes from a site to a person. It consists of five elements. All of the elements must be present at the same time, or can reasonably be expected to be present at some time. These are:

  • a source of contamination
  • environmental media and transport mechanisms
  • a point of exposure
  • a route of exposure, and,
  • a receptor population.

Other pathways considered are "potential pathways," that is, those in which exposure might have occurred, may be occurring, or may yet occur; and "eliminated pathways," that is, those that can be eliminated from further analysis because one of the five elements is missing and will never be present, or in which no contaminants of concern can be identified.

The ATSDR and the NJDHSS reviewed environmental sampling results to learn if completed exposure pathways exist now or in the past, or are likely to occur in the future. Where these pathways exist, the ATSDR and NJDHSS also determine the impact these contaminants might have on health, based upon the amount of contamination present, the ways that people are exposed to the contaminants, and the length of time people may have been exposed.

Surface and sub-surface soil and indoor air have been tested for contamination relating to coal tar creosote. In addition, the likelihood of exposure through garden vegetable contamination has been considered. A summary of completed and potential exposure pathways is presented below.

Pathway Name Exposure Pathway Element Time Complete or Potential
Environmental Media Point of Exposure Route of Exposure Receptor Population
Residential soil in Claremont Development Surface soil Residential yards Dermal Residents in several houses in Claremont Development above former creosote lagoons Past Complete
Sump pump Sump material (raw product) At the pump Dermal Residents over former lagoons and canals Past Complete
Sump pump Sump material (raw product) At the pump Inhalation Residents over former lagoons and canals Past Complete
Residential soil in Claremont Development Subsurface soil Residential yards Dermal Residents above former creosote lagoons and canals Past
Present
Future
Potential
Residential soil in Claremont Development Subsurface soil Residential yards Inhalation Residents above former creosote lagoons and canals Past
Present
Future
Potential
Residential soil in Claremont Development Subsurface soil Residential yards Ingestion Residents above former creosote lagoons and canals Past
Present
Future
Potential
Garden vegetables Contaminated garden produce Residence Ingestion Residents growing food products in contaminated soil Past
Present
Future
Potential
Potable water Groundwater Residence Ingestion Residents served by the municipal water supply Future Potential

Other than the sump pump inhalation exposure, indoor air has been eliminated as an exposure pathway because contaminant levels measured were less than health-based guidelines, and because they were not from coal tar creosote.

The USEPA has placed monitoring wells throughout the area to learn the extent of groundwater contamination. Although municipal wells are presently unaffected by the site, the groundwater beneath the site is contaminated with components of creosote. Because there are no private wells in the community, there is no pathway associated with groundwater at the present time. However, there is a potential that public wells could be affected in the future if the site is not remediated.

C. Health Effects From Exposures

For those compounds which were found in a completed or potential exposure pathway, information on health effects at the levels measured in the environmental media are discussed. The toxicity of coal tar creosote varies according to both its constituent compounds and the route of exposure (oral, dermal, inhalation). Based on industrial and animal studies, the most likely health effects from coal tar creosote exposure are to the respiratory, dermal and ocular systems. Dermal exposure to coal tar creosote is associated with the most serious effects, including skin damage and sensitivity to sunlight, or reddening, blistering or peeling of the skin. It may also cause irritation of the respiratory tract. Some of the PAHs, including benzo[a]pyrene, are known animal and probable human carcinogens.

Exposures through surface soil

Surface soil is of concern because of the high probability that residents may have contact with this environmental medium. Children are especially at risk because they are the most likely segment of the population to ingest soil. Soil ingestion may be accidental, as in putting items in their mouths that may have soil on them, or deliberate in the case of pica children. (Pica is a condition in which a person deliberately eats non-food items, such as dirt or paint chips.) Children's activities may also place them at higher risk for exposures to their skin (dermal exposure). Adults who garden or landscape may also have an increased risk of dermal exposure to soil contaminants.

Two rounds of surface soil sampling have occurred which formed the basis of two earlier health consultations (ATSDR, January 16, 1998; ATSDR, February 11, 1999). In the first of these, total PAHs were measured and converted to benzo[a]pyrene equivalents. For the highest benzo[a]pyrene equivalent, cancer assessments were performed for children and adults. A cancer assessment is a calculation based upon actual contaminant levels, assumed daily ingestion amounts, and a cancer slope factor established by the USEPA. As noted in the January 16, 1998, Health Consultation, the cancer risk for adults at this site is 1.8 excess cancer cases for each 10,000 individuals exposed. For children, a cancer risk assessment yielded a cancer risk factor of almost 7 excess cancers per 10,000 children exposed. The Health Consultation then states that the actual cancer risk is likely to be much lower than the calculated risk, because 1) the calculations assume that there is daily (year round) ingestion of soil with the highest levels of contaminants measured; 2) PAHs bind to soil by varying degrees, depending upon the size of the particular PAH and the amount of organic material in the soil. By being bound to the soil, these PAHs are not as available to be taken up by the body. It also makes them less likely to be absorbed dermally; 3) there is an assumption that there is no vegetative cover over these areas; and 4) areas of suspected contamination were chosen for sampling, although there was no visible contamination of the soil.

To ensure public health and safety, the USEPA provided temporary remediation of 19 properties with the highest soil PAH levels.

Because only a limited number of properties were evaluated, and only one sample per property was collected, ATSDR recommended that more extensive sampling of surface soil be conducted to be more representative of residential exposures to surface soil contaminants. In early 1998, nearly all of the properties in the Claremont Development were tested more thoroughly for metals, volatile and semi-volatile organic compounds, pesticides, and PCBs, in order to characterize site contamination. ATSDR evaluated lead, arsenic, and PAH results for their health implications. Sampling data is more thoroughly reviewed in the February 11, 1999, Health Consultation. PAHs (in benzo[a]pyrene equivalents) at the highest levels found in surface soil were below levels associated with cancer or non-cancer effects in adults and children, including pica children.

The February 11, 1999, ATSDR Health Consultation uses 500 mg/kg of lead in residential soil as a level of public health concern. One residence had one sample with lead above this level. Follow-up sampling at this property was conducted to determine the extent of lead contamination. These follow-up samples did not have lead levels in excess of 500 mg/kg, and the earlier result is believed to be an anomaly.

Arsenic levels exceed the EMEG for a pica child, but are below levels that are hazardous to non-pica children and adults. The cancer risk to a pica child from benzo[a]pyrene equivalent exposures is 6.8 excess cancers per 10,000 people exposed. For the reasons discussed above, it is unlikely that exposures to arsenic in soil actually occur at levels that would result in this cancer risk.

Exposures through sub-surface soil

Coal tar creosote has been visually identified in sub-surface soil, at less than 2 feet below ground level in some properties in the Claremont Development. Polycyclic aromatic hydrocarbons and volatile organic compounds have been measured at varying depths.

Human exposure to sub-surface contaminants is not as likely as exposure to surface soil. Sub-surface soil is, however, a potential completed exposure pathway for residents living on contaminated properties. The ATSDR May 1, 1997, and January 16, 1998, Health Consultations discuss the health issues related to coal tar creosote and the PAHs found in sub-surface soil. The levels of PAHs found are associated with dermal effects. Long-term exposure to the cancer- causing PAHs may increase the risk of developing cancer.

Exposures through garden produce

Residents were concerned that produce grown on-site would increase their exposures to site-related contaminants. The ATSDR performed a health consultation on this issue in April 1998. Vegetables can become contaminated by PAHs in two ways: PAHs may be adsorbed (adhere to) the plant surface, or they may be taken up into the plant. Some of the PAHs that are found on plant surfaces are washed away by rain, or break down into other products. At harvest time, some of those remaining can be removed by washing or peeling. Only a small percentage (less than 1 percent) of the PAHs in soil are taken up by the plant. Although PAH concentrations in garden produce are generally less than that of the soil in which they are grown, consumption of vegetables grown on the more highly contaminated properties was thought to increase an individual's total PAH intake to unacceptable levels.

Because of the surface soil remedial activities that have occurred, and the low levels of PAHs which may have been taken up by plants in the past and present, the ATSDR believes that residents are not likely to be exposed to levels of PAHs in garden produce at levels which may affect health.

Exposures through groundwater

The USEPA has indicated that creosote has entered area groundwater. Delineation of the extent of the plume in ongoing. While municipal wells, located 1/4 mile from the site, are not currently impacted, the USEPA believes that removal of the source material is necessary to prevent further contamination to groundwater.

D. Health Outcome Data

Health outcome data was not evaluated for this site. An evaluation of health outcome data for the small number of individuals who may be affected by the site may not yield scientifically meaningful information.

E. Community Health Concerns

Community concerns, as related to the ATSDR, relate to the effects of long-term exposures to creosote. There are also concerns on its potential effects on children's health. Residents wanted assurances that remediation would not result in additional exposures through dust and soil movement.

Because of the expected permanent and temporary removal of people from their homes, ATSDR met with residents in January 1999 to discuss stress-related issues. A second meeting with residents was held in September 2000, as long-term remediation activities (i.e., permanent relocation) began.

F. Public Comment

The Public Comment period was July 10 - August 21, 2000. All residents in the Claremont Development were provided with a copy of the draft Public Health Assessment. In addition, two availability sessions were held on July 18, 2000. Most community concerns related to issues addressed by the USEPA, including relocation issues, specific sampling data for a property, ultimate disposition of the creosote removed, and potential for noise during the remediation. One resident, concerned that her dog might be exposed to creosote by digging in the yard, was advised that the concentration of contamination in the backyard was minimal. A resident with concerns about garden produce safety was given advice about container and raised-bed gardening techniques.

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