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1. ATSDR > Public Health Assessments & Consultations

The Toxic Chemical Release Inventory (TRI) database search was conducted and no information about the site or the surrounding areas was found.

A. On-Site Contamination

Samples, collected on December 20, 1984 by NUS Corporation, were taken from four on-site sampling locations: the east drainage ditch, the old fire pond, the railroad loading dock foundation, and the field in the center of the site. Sediment and aqueous samples or a soil sample were taken at each location. The soil sample was taken less than three inches from the surface.

Based on the limited quantity and quality of data available for this site a list of contaminants of concern and the range of concentrations is presented in Table 1 below. Except for a high lead concentration found in one sediment sample, inorganic elements are within expected background levels, however some elements did not screen out because they exceeded health based comparison values set to protect a child who may habitually consume soil. Arsenic is within Eastern United States regional and local background levels but exceeds the Reference Dose (RfD) based comparison value for the child who habitually ingests soil and is a known human carcinogen. The highest concentrations of sediment contaminants were found in a southwest depression area incorrectly termed the old fire pond where concentrations of individual polycyclic aromatic hydrocarbons (PAHs) ranged from 25.2 milligrams per kilogram (mg/kg) to 90.7 mg/kg. The old foundation, where the seep was observed, had concentrations of PAHs ranging from 11.4 mg/kg to 36.0 mg/kg and concentrations of PAHs in the east drainage ditch sediments ranged from 2.41 mg/kg to 6.62 mg/kg. Soil concentrations in the field had PAH concentrations from 2.66 mg/kg to 9.72 mg/kg.

None of the aqueous samples are of adequate quality to evaluate site contamination. The Quality Assurance and Quality Control Section below provides an explanation of the inadequacies in sampling.

B. Off-Site Contamination

Off-site sampling of sediment from Hershey Run and White Clay Creek consisted of grab sampling and was conducted at the same time as the on-site sampling. The same contaminants and the same quality control problems that existed for the on-site samples existed for the off-site samples. A list of contaminants of concern and their ranges of concentrations is presented in Table 2. In Hershey Run, PAH concentrations ranged from 896 mg/kg to 10,600 mg/kg; however, concentrations in samples upstream of the site are higher than concentrations in samples adjacent to the site.

Table 1. Ranges of On-Site Soil and Sediment Contamination
(Sampling date: 12-20-84 Ref. 2)

A - Based on 1 valid sample.
CREG - ATSDR lifetime cancer risk concentration level derived from EPA cancer slope factor.
Background - Eastern United States Background Concentration Levels.
EMEG - Environmental Media Evaluation Guides are media specific comparison values developed by ATSDR.
ND - Not Detected.
P - exceeds only pica-child comparison value.
RfD - An EPA estimate of daily exposure that is likely to be without appreciable risk of deleterious health effects. A RfD based comparison value is used when no EMEG is available.

Table 2. Ranges of Off-Site Sediment Contamination
(Sampling date: 12-20-84 Ref. 2)

A - Based on 1 valid sample.
CREG - ATSDR lifetime cancer risk concentration level derived from EPA cancer slope factor.
Background - Eastern United States Background Concentration Levels.
EMEG - Environmental Media Evaluation Guides are media specific comparison values developed by Agency for Toxic Substances and Disease Registry.
P - exceeds only pica-child comparison value.
RfD - An EPA estimate of daily exposure that is likely to be without appreciable risk of deleterious health effects. A RfD based comparison value is used when no EMEG is available.

C. Quality Assurance and Quality Control

In preparing this health assessment, ATSDR relies on the information provided in the referenced documents and assumes that adequate quality assurance and quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The analysis and conclusions in this Health Assessment are valid only if the referenced information is complete and reliable.

Samples were analyzed for metals, pesticides, PAHs, and some volatile organic compounds (VOCs). Inappropriate detection limits, excessive holding times, or contaminated laboratory blanks rendered much of the data unusable. The surface water samples and some sediment samples were not acceptable for evaluating the degree and extent of contamination at the site. White Clay Creek samples, for example, were completely unusable for the reasons stated above; therefore, the contamination in the creek cannot be evaluated.

D. Physical and Other Hazards

A pit, located near the site's eastern boundary and surrounded by dense vegetation and covered by boards presents a potential physical hazard to persons who could fall accidently into the hole. There is a possibility that other physical hazards may exist, but no other hazards were identified in site documentation, nor was the site visit team able to visually inspect the entire site because of thick underbrush.

PATHWAYS ANALYSES

A. Pathways Introduction

ATSDR utilizes a pathways analysis to evaluate the potential for human exposure to site contaminants. An exposure pathway consists of five elements:

1. a source of contamination,
   
2. a contaminated environmental media,
   
3. a point of exposure,
   
4. a route of exposure, and
   
5. a receptor population.

An example of an exposure pathway would be a source of waste drums which leaked into the groundwater which was used by residents having private wells for drinking, showering and other household purposes. Exposure pathways are considered to be complete if all five elements are present and are adequately characterized to link the site to a specific receptor population. A potential pathway exists when one or more of the five elements is missing or is inadequately characterized. Due to the limited nature of the sampling data, we have not been able to identify any completed exposure pathways for the Koppers site at this time. Table 3 lists the potential exposure pathways evaluated at the Koppers site. Table 4 summarizes the potentially exposed population estimates and site contaminants for the Koppers Delaware site.

B. Potential Exposure Pathways

Surface soil and sediment pathway

Industrial or treatment process chemicals were dumped or spilled onto the soil or into waste ponds at the Koppers facility and may result in past, present, or future potential exposures to those chemicals. PAHs were one of the major contaminants in soil and can migrate to surface water, ground water, and air. Since PAHs as a group tend to have low solubilities in water, they are primarily found sorbed to sediment particles that either settle to the bottom or banks of surface water bodies or are suspended in the water column. The mobility of PAHs in soil is highly dependent on soil particle size. Exposure to contaminants in soil and sediment is primarily through incidental ingestion, although dermal exposure and inhalation of contaminated dust particles may occur.

The populations most likely to be exposed are the residents along Old Airport Road, a small number of hikers and hunters trespassing on the site, and recreational users who use the areas adjacent to the site.

Of three subpopulations of nearby residents, children less than six years in age, children six to eighteen, and adults, children under six are the most sensitive to contaminants and the largest consumers of soil. Children in the six to eighteen age group will frequent the site more often but will consume less soil than younger children. Adults ingest the least amount of soil and are the least likely to wander onto the site. Some adults and/or teenagers have found the area attractive for hunting, although hunting is seasonal and would lead to infrequent exposure. Recently, two teenagers were picked up by DuPont/Ciba Geigy security for trespassing on the site.

There is also potential exposure to soils and sediments by remediation workers and potential exposure from ingestion and dermal contact with contaminated sediments by recreational users of the Christina River. Whether or not the exposure exists can only be determined by further sampling and analysis, as the present data is too meager to adequately characterize the site.

Table 3. Potential Exposure Pathways

Pathway	Time	Source of Contamination	Environmental Media and Transport	Point of Exposure	Route of Exposure	Receptor Population
Surface Soil	Past Present Future	Koppers process waste	Surface soil	On site	Ingestion, dermal absorption	Trespassers, hunters, remedial workers
Sediment	Past Present Future	Koppers process waste, on site contaminated soil	Sediment	On site and off site Hershey Run Christina River White Clay Creek	Ingestion, dermal absorption	Trespassers, recreational users of Christina River, remedial workers
Private Well	Past Present Future	Koppers process waste	Ground water	Residences, businesses	Ingestion, dermal absorption, inhalation	Residents & workers along Old Airport Road
Terrestrial Organisms	Past Present Future	Koppers process waste, on and off site contaminated soil and sediment	Deer, dove	Residences of hunters	Ingestion	Hunters eating their kill
Aquatic Organisms	Past Present Future	Koppers process waste, on and off site contaminated sediment	Fish	Residences of fishers	Ingestion	Fishermen eating their catch
Ambient Air	Past Present Future	Koppers process waste, other area industries, on and off site contaminated sediment and soil	Air	On and off site	Inhalation	Residents of Newport, remedial workers, trespassers, hunters
Surface Water	Past Present Future	Koppers process waste, on and off site contaminated soil and sediment	Surface water	On and off site	Dermal absorption, ingestion	Recreational users of Christina River, Hershey Run, White Clay Creek

Table 4. Estimated Population for Potential Exposure Pathways

Potentially Exposed Populations			Affected by a Potential Exposure Pathway for:
Population Location		Estimated Persons	Arsenic	Barium	Cadmium	Chromium	Lead	Manganese
Residents of Newport, south of Newport Pike		300	Sediment	Surface Soil, Sediment	Sediment	Surface Soil, Sediment	Surface Soil, Sediment	Surface Soil, Sediment
Residents and Workers along Old Airport Road		100	Not Known	Not Known	Not Known	Not Known	Not Known	Not Known
Trespassers	Residents & Children	Not Known	Sediment	Surface Soil, Sediment	Sediment	Surface Soil, Sediment	Surface Soil, Sediment	Surface Soil, Sediment
	Hunters	Not Known	Sediment, Deer, Dove	Surface Soil, Sediment, Deer, Dove	Sediment, Deer, Dove	Surface Soil, Sediment, Deer, Dove	Surface Soil, Sediment, Deer, Dove	Surface Soil, Sediment, Deer, Dove
People Fishing on Christina River		Not Known	Fish	Fish	Fish	Fish	Fish	Fish

Table 4. continued

Potentially Exposed Populations			Affected by a Potential Exposure Pathway for:
Population Location		Estimated Persons	Mercury	Silver	Vanadium	Phenanthrene
Residents of Newport, south of Newport Pike		300	Sediment	Sediment	Surface Soil, Sediment	Sediment Air
Residents and Workers along Old Airport Road		100	Private Wells	Private Wells	Private Wells	Private Wells Air
Trespassers	Residents & Children	Not Known	Sediment	Sediment	Surface Soil, Sediment	Sediment Air
	Hunters	Not Known	Sediment, Deer, Dove	Sediment, Deer, Dove	Surface Soil, Sediment, Deer, Dove	Sediment, Deer, Dove Air
People Fishing on Christina River		Not Known	Fish	Fish	Fish	Fish

Table 4. continued

Potentially Exposed Populations			Affected by a Potential Exposure Pathway for:
Population Location		Estimated Persons	Chrysene	Fluoranthene	Benzo(a)- anthracene	Benzo(a)-pyrene	Benzo(b)-fluoranthene	Benzo(k)-fluoranthene
Residents of Newport, south of Newport Pike		300	Surface Soil, Sediment, Air	Surface Soil, Sediment, Air	Surface Soil, Sediment, Air	Surface Soil, Sediment, Air	Surface Soil, Sediment, Air	Surface Soil, Sediment, Air
Residents and Workers along Old Airport Road		100	Private Wells Air	Private Wells Air	Private Wells Air	Private Wells Air	Private Wells Air	Private Wells Air
Trespassers	Residents & Children	Not Known	Surface Soil, Sediment Air	Surface Soil, Sediment, Air	Surface Soil, Sediment Air	Surface Soil, Sediment Air	Surface Soil, Sediment Air	Surface Soil, Sediment
	Hunters	Not Known	Surface Soil, Sediment, Deer, Dove Air	Surface Soil, Sediment, Deer, Dove Air	Surface Soil, Sediment, Deer, Dove Air	Surface Soil, Sediment, Deer, Dove Air	Surface Soil, Sediment, Deer, Dove Air	Surface Soil, Sediment, Deer, Dove
People Fishing on Christina River		Not Known	Fish	Fish	Fish	Fish	Fish	Fish

Private well pathway

Contaminants from the Koppers site can migrate to ground water either directly from contaminated surface waters or through the soil. Two major aquifers underlie the Koppers site: the shallow Columbian Formation and the deeper Potomac Formation. The shallow Columbian Formation, which is 10 to 20 feet below the surface and 20 to 30 feet thick, flows south toward the Christina River. The deeper Potomac Formation is interspersed with layers of clay and silt, which are discontinuous, and are separated horizontally and vertically by clay layers. The thickness and extent of these confining layers is variable suggesting that the two aquifers may be connected. Flow in the deep aquifer is generally to the southeast toward the Christina River. The deeper Potomac aquifer is the major source of public well water in the area, although both aquifers are sources for private drinking water supplies (6, 7, 8).

Ground-water data are needed to determine whether PAHs or other contaminants, like pentachlorophenol which was not detected but was known to have been used on the site, have leached from on-site, contaminated soil and whether subsequent migration of PAH-contaminated ground water has contaminated nearby private wells.

Private well users along Old Airport Road have expressed concern over the potential for chemicals from the DuPont and Ciba Geigy plants, adjacent to our site, to contaminate their private wells. With respect to the Koppers site, no evidence exists to suggest that chemicals from the site have migrated in the direction of the wells on Old Airport Road. However, the shallow aquifer is so close to the contaminated soil, PAHs and other organic chemicals such as pentachlorophenol could leach into the ground water at a site. This contaminated ground water could then migrate to nearby wells thus exposing residents who use their well for drinking water. Therefore, on-site ground water data is needed to evaluate this exposure pathway.

Biota pathways

Improper waste and chemical handling at the Koppers site has resulted in contaminated soil at the site. The soil was moved during storm flow into surface water bodies and possibly contaminated surface water bodies and stream sediments. The fact that PAHs readily assimilate and bioaccumulate in some organisms suggests that aquatic organisms (e.g., polychaete worms, mollusks, crustaceans, and fish) and terrestrial organisms (e.g., plants, worms, insects, mammals) could introduce PAHs into the food chain. Experiments indicate that while aquatic organisms do assimilate PAHs, biomagnification, a systematic increase in tissue contamination concentrations moving up the food chain, may not be a factor because of the tendency of many aquatic organisms in the higher trophic levels to metabolize and eliminate these compounds (9). The potential for exposure through the food chain by hunters eating the game they kill as well as fishers eating the fish they catch may exist. Because sampling has not been conducted in biota (e.g., plants, fish, deer, doves) it is not known whether on-site contaminants are resulting in human exposures via these pathways.

Ambient air pathways

Improper disposal of process chemicals or from improper handling of materials during operations of the wood-treatment facility allowed for contamination of soil and possibly surface water at the site. Of the contaminants identified in the site soils, PAHs volatilize from the soil or water to air. Exposure to volatile contaminants could occur on or off of the site by nearby residents and workers, site workers, and trespassers. Although no air monitoring data have been collected, odors reported by residents in 1978 suggest that contaminants, at one time, volatilized into the atmosphere. Air monitoring by EPA in 1980 using organic vapor analyzers did not detect elevated levels of organic chemicals; however, the sensitivity (i.e., ability to detect smaller amounts of substances) of these instruments is too poor to characterize adequately the air quality on the site. In addition, these instruments do not measure semi-volatile compounds such as PAHs and pesticides. Therefore, sufficient environmental data is needed to determine whether organic chemicals are evaporating into the air. Inhalation of fugitive dust containing PAHs and heavy metals, though it has not been tested for, is not a likely pathway considering the heavy vegetation covering the site.

Surface water pathways

Contaminants from industrial processes at the Koppers treatment plant were spilled or dumped onto soil or into waste ponds. The contaminants including heavy metals and PAHs could migrate as contaminated soil particles in storm runoff or the contaminants could migrate directly into surface water bodies from the soil. Contaminated groundwater may also discharge into surface water bodies and contribute to contamination. The presence of PAH-contaminated sediments in Hershey Run suggests that surface water could contain PAHs. However, lower molecular weight PAHs (e.g. anthracene, fluorene, phenanthrene), generally volatilize rapidly from surface water. Middle or higher molecular weight PAHs (e.g., pyrene, benzo(a)anthracene, benzo(a)pyrene, chrysene) generally sorb to particulate and settle to the bottom of the stream as sediments or remain suspended in the water column. The primary points of exposure to contaminated surface water would be on the Christina River, Hershey Run, White Clay Creek and the wetlands areas. On-site exposure to contaminated surface water may be possible if ponds form from storm water in low areas of the site. Recreational users wading or swimming in the water would have dermal exposure to contaminants as well as incidental ingestion of surface water.

PUBLIC HEALTH IMPLICATIONS

As discussed in the "Environmental Contamination" and "Pathway Analysis" sections, hunters and other trespassers at the site may be exposed to contaminants through dermal contact with contaminated soil, seepage, or sediment. In addition, the potential exists for exposure of private well users to site contaminants via the groundwater pathway. This is considered a potential exposure pathway because no data exist to determine whether groundwater contamination is present and if subsequent exposure might be occurring. Finally, because hunters use the site, there is a potential for exposure via the food chain pathway. However, more data is needed to discern the potential or presence of this exposure route. In this section we will discuss the health effects in exposed persons affected by site contaminants and address specific community health concerns.

A. Toxicological Evaluation

Introduction

To evaluate health effects, ATSDR has developed Minimal Risk Levels (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur. MRL's are developed for each route of exposure, such as ingestion, inhalation, and dermal absorption and for the length of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (greater than 365 days). ATSDR also develops Toxicological Profiles on chemicals commonly found at hazardous waste sites. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status. The ATSDR Toxicological Profiles used in the preparation of this report include Polycyclic Aromatic Hydrocarbons, Arsenic, Cadmium, Chromium, Lead, Mercury and Zinc.

To evaluate the toxicological implications of the chemicals identified at or near the Koppers site four different exposure scenarios were assumed to have been possible. Firstly, an adult hunter weighing 70 kg was assumed to gain access to the site 20 days/year for as much as 20 years, the length of time since plant closure. Secondly, a teen-age trespasser weighing 60 kg was assumed to have gained access to the site 20 days/year for 6 years, the time span of the teen years. Thirdly, a child trespasser weighing 35 kg was assumed to gain access to the site 20 days/year for 3 years, the time span of preteen years. Lastly, a 10 kg child with habitual pica was assumed to come onto the site with an adult hunter or recreational user. The time span of exposure was 20 days/year for one year, the most likely period of pica activity.

Only potential exposures through on-site soil or on-and off-site sediment were evaluated due to the limited sampling data. No distinctions were made at this time between frequency of ingestion of soils or sediment. Uncertainty exists in these calculations because very often there was only one valid sample to represent the entire site. The following discussion includes chemicals that exceeded a health guideline for potential exposures using the above scenarios.

Polycyclic aromatic hydrocarbons

Benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, chrysene, fluoranthene, and phenanthrene are all polycyclic aromatic hydrocarbons. Dermal contact with high concentrations of polycyclic aromatic hydrocarbons (PAHs) may cause irritation, burning, inflammatory spots on the skin, eruption of blood vessels and cause sensitization to sunlight. Little is known about the uptake, assimilation, and accumulation of PAHs in terrestrial organisms, especially at the higher trophic levels. The carcinogenic potential of certain PAHs can be either diminished or enhanced by metabolic activity. Certain enzyme systems may cause deactivation of the PAH's, making them less toxic and excretable, or they may cause activation, increasing the toxicity of the PAH's, by forming metabolites that bind to cellular genetic material which may cause mutagenicity, cell transformation, or cancer. The activation or deactivation activity is dependent on the type of tissue and the specific PAH involved. The metabolism of PAHs does not necessarily mean a safe elimination as many of the metabolites are more toxic than the original PAH (9). Generally, PAHs are metabolized and eliminated in fish but it is not known how they interact with birds, mammals, or humans. The limited mobility of PAHs in soils and sediment suggest that ingestion through the food chain, if occurring, may be limited (9).

Studies have found that two PAHs found at the site, benzo(a)pyrene and benzo(b)fluoranthene, are considered to be carcinogenic. It has been shown that exposure to the non-cancer causing PAHs with cancer causing PAHs greatly increases the potency of the cancer causing PAHs (9).

With the known data, it is impossible to ascertain the entire potential cancer effects to individuals from exposure to PAH contaminated media from this site. In this evaluation benzo(b)fluoranthene, benzo(a)anthracene, benzo(k)fluoranthene and chrysene were all assumed to have the same carcinogenic potential as benzo(a)pyrene. The potential of cancer effects for one year of exposure for the pica child to on-site sediment and soil exceeded health guideline values for all evaluated PAHs. The hunter may experience a very low level of increased cancer risk from incidental ingestion of on-site sediment due to exposure to benzo(b)fluoranthene and chrysene. There was only one valid sample for on-site surface soil for these PAHs.

Arsenic

Arsenic enters the body primarily through the mouth, in food or water, where it is ingested and then quickly absorbed into the bloodstream. It can be inhaled, and is also absorbed quickly. The systemic effects of arsenic poisoning include pain, nausea, diarrhea, abnormal heart function, impaired nerve function, blood-vessel damage, liver or kidney damage, and a pattern of skin abnormalities including hyperpigmentation and the appearance of small "corns" on the palms, soles of feet, and trunk. Direct dermal contact with high concentrations of arsenic can result in local inflammation and blistering. Arsenic has been reported as increasing the risk of cancer in the body when ingested or inhaled. Individuals who are at increased risk from arsenic exposure include: smokers, people who work at a smelter or live near one, those who work with pesticides, and those with diseases of the skin, blood, liver, kidney, and central nervous system. There is clear evidence that chronic oral exposure to elevated levels of arsenic increases the risk of skin cancer, as well as for other cancers in the body, and especially lung cancer (10). The pica child exposure dose for off-site sediment ingestion exceeds the Reference Dose for noncarcinogenic effects of arsenic. There was only one valid sample for on-site sediment arsenic levels. There was no arsenic detected in the on-site soil sample. Any off-site sources of arsenic have not be investigated.

Cadmium

Cadmium enters the body primarily through inhalation, although exposure can occur through ingestion. Once cadmium enters the body, its retention is very strong. Acute exposure causes vomiting, diarrhea or severe irritation of the lungs. Chronic exposure is of greater concern and may result in kidney damage, lung damage, lung cancer, and high blood pressure. Other tissues that might be injured include the liver, testes, immune system, nervous system, and blood. Studies suggest an increase in lung cancer and possibly prostatic cancer in exposed workers, although there are little data accumulated on human carcinogenicity from cadmium exposure. Populations at special risk include individuals with renal disease or other etiology, dietary deficiencies in metal ions and/or proteins, neonates, young children, workers in smelters, and smokers (11). Sampling data for on- and off-site sediment indicates we should expect no short-term adverse health effects except in the remote possibility of intrusion on the site by a pica child.

Lead

Studies have shown that lead exposure may cause premature birth, reduced birth weight, and decreased intelligence quotient (IQ) for babies whose mothers have been exposed. Lead exposure may also decrease IQ and retard growth in young children and increase blood pressure in middle-aged men. Higher levels of lead exposure can lead to severe brain and kidney disease in both adults and children. Rats treated orally with soluble lead compounds show significantly increased incidence of kidney tumors. There are no MRLs or Reference Doses (RfD) for lead; however, the infrequent exposures expected at this site are not likely to result in adverse health effects (12).

Other chemicals

Other chemicals, such as pentachlorophenol (PCP), were known to be used at the site. Additional data are needed to ascertain the presence of this or other contaminants and, if they exist, to determine the degree of contamination and the health implications.

B. Health Outcome Data Evaluation

Although the Delaware Department of Public Health keeps a database that can provide public health information for the area around the Koppers site, we must first have more complete site characterization in order to, 1), determine what data to request, and 2), properly evaluate this public health data.

C. Community Health Concerns Evaluation

Data does not exist to evaluate public health concerns. Two public health concerns were uncovered: complaints by residents claiming odors from the site caused nausea, burning throats and noses, and watery eyes; and concerns by private well users along Old Airport Road over the potential for chemicals from the DuPont and Ciba Geigy plants, adjacent to our site, of contaminating their private wells. In both cases more sampling is needed to determine if PAHs or other organic compounds are volatilizing into the atmosphere or if contaminants are being transported via ground-water movement into private wells.

Agency for Toxic Substances and Disease Registry, 1825 Century Blvd, Atlanta, GA 30345
Contact CDC: 800-232-4636 / TTY: 888-232-6348 

Department of Health and Human Services