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The tables in this section list the contaminants of concern. NJDOH evaluates these contaminants in the subsequent sections of the Health Assessment to determine whether exposure to them has public health significance. NJDOH selects and discusses these contaminants based upon the following factors:

  • Concentrations of contaminants on and off the site.

  • Field data quality, laboratory data quality, and sample design.

  • Comparison of on-site and off-site concentrations with health assessment comparison values for (1) noncarcinogenic endpoints and (2) carcinogenic endpoints.

  • Community health concerns.

In the data tables that follow under the on-site Contamination subsection and the off-site Contamination subsection, the fact that a contaminant is listed does not mean that it will cause illness or injury if exposures occur. Instead, the list specifies contaminants that will be further evaluated in the public health assessment.

The Data tables include the following acronyms:

  • CREG
= ATSDR Cancer Risk Evaluation Guide
  • EMEG
= ATSDR Environmental Media Evaluation Guide
  • RMEG
= Reference Dose Media Evaluation Guide, calculated from EPA's reference dose (RfD).
  • LTHA
= USEPA's Lifetime Health Advisory
  • NJ MCL
= NJ Maximum Contaminant Level
  • PPB
= Parts Per Billion
  • PPM
= Parts Per Million
  • ND
= Not Detected

ATSDR health assessment comparison values are contaminant concentrations in specific media that are used to select contaminants for further evaluation. These values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant guidelines. CREGs are estimated contaminant concentrations based on a one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factors. Maximum contaminant levels (MCLs) represent contaminant concentrations that New Jersey or a Federal regulatory agency, eg. EPA, deems protective of public health (considering the availability and economics of water treatment technology) over a lifetime (70 years) at an exposure rate of 2 liters of water per day. MCLs are regulatory concentrations. EPA's Reference Dose (RfD) is an estimate of the daily exposure to a contaminant that is unlikely to cause health effects.

The environmental contamination section includes sampling data from a variety of media sources including: groundwater (monitoring wells and residential wells); surface water; surface soil; subsurface soil; and sediments.

A. On-site contamination

Between 1981 and 1993, various samples from an-site environmental media were analyzed. The collection and analysis of the samples were initiated by the NJDEPE and the USEPA.


In one of the earliest episodes of soil sampling at the Horseshoe Road site, May 1985, the NJDEPE conducted a dioxin investigation at the Atlantic Resources section of the site. Dioxin was detected at concentrations as high as 14.18 ppb.1 These tests also revealed high concentrations of volatile organic compounds (VOCs), heavy metals, and base-neutral compounds. PCB's were also detected in concentrations ranging from 16 - 27 ppm.

In February, 1989 the United States Environmental Protection Agency (USEPA) conducted a soil investigation at the site (Sayreville Pesticide Dump) which revealed elevated levels of the following contaminants: aluminum, arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, manganese, nickel, vanadium, zinc, and 1,2,4-trichlorobenzene.1

In September 1989 the USEPA authorized additional site investigations, which included some small scale soil sampling which showed extensive contamination. Contaminants identified included: toluene, chloroform, ethylbenzene, 1,2-dichloroethane, nitrobenzene, methoxychlor, arochlor-1254 ...etc.1

The first comprehensive studies of soil contamination at the Horseshoe Road site were conducted for Target Compound List (TCL) contaminants, September 23, 19936, and for metals, August 28, 19937, by the USEPA. The USEPA used surveying equipment to delineate a 50-foot inter-nodal grid system an the site, and surface soil (0-12") samples were taken at the grid axes. Figure 5 shows the location of these samples.

Table's # 1-5 shows the contaminants of concern detected (maximum concentration) in on-site surface soil samples.

Results of the chemical analysis of these soil samples indicate that the sampled area was heavily contaminated with a wide variety of VOCs and phenols (Table # 1), PAH's (Table # 2), pesticides (Table # 3), PCB's (Table # 4), and inorganic compounds (Table # 5), including metals.

Although not specifically noted in the latest soil survey, the NJDEPE, during a 1985 Phase II Dioxin Study, located an area within the fence of Atlantic Resources which had 14.18 ppb 2,3,7,8-TCDD(dioxin) contamination in the soil.1

B. Off-site contamination

As noted in the 1991 ATSDR health consultation on the Horseshoe Road site, data concerning off-site contamination were limited, however, there was evidence that off-site migration is occurring5. The report noted that toluene was found in the air downwind of the site indicating that other contaminants (e.g., vinyl chloride and other VOCs) may, on occasion be carried, off site. High levels of pesticides and PCBs in sediments in areas of water runoff suggested that contamination of wildlife and fish may be occurring at the site.

The Horseshoe Road site is located less than 200 feet of the Raritan River. According to the USEPA, oil stains found on the site's pipe culvert and drainage ditch which carry runoff water from the site, indicate that contaminants have entered the river. This drainage ditch contains no vegetation and dead animals (e.g. muskrat, rabbit) have been found nearby. The exact cause of the death of these animals was not apparent, but they were suspected to be related to site discharges.

According to the Middlesex County Health Department, oil sheens have been observed at the site on several occasions, at the point where the drainage ditch meets the Raritan River. The extent to which off-site groundwater is contaminated, if at all, can not be determined at this time due to a lack of groundwater data.

C. Quality Assurance and Quality Control

In preparing this Public Health Assessment, ATSDR and NJDOH rely on the information provided in the referenced documents and assumes that adequate quality control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of analysis and conclusions drawn for this health assessment is determined by the availability and reliability of the referenced information.

D. Physical and Other Hazards

The site contains several physical hazards. On-site buildings are guarded by security personnel, however, any trespassers entering the area would be at great physical risk due to the dilapidated condition of the structures. The perimeter of most of the site is fenced to prevent unauthorized access, but there are areas outside where drum carcasses and other debris have been noted. The rusted and deteriorated condition of some of these materials could cause physical harm and/or injury to trespassers, particularly children. Another source of potential physical harm was noted at the Horseshoe Road Dump area. There were numerous ragged and sharp pieces of circuit board material protruding from the dump.

A geophysical investigation conducted at the site in June 1991 by NJDEPE identified additional hazards.8 Using magnetic and electromagnetic terrain conductivity techniques they determined that there were three major anomalous areas, possibly indicating the presence of buried drums. One area is the Horseshoe Road dump site west of the Atlantic Resources building, the second is near the southern end of the fence surrounding the Sayreville Pesticide Dump and the third is under the berm south of the Clover Chemical building.

There are no known or suspected radiological or biological hazards associated with the site.

E. Toxic Chemical Release Inventory Data

The NJDOH conducted a search of the Toxic Chemical Release Inventory (TRI) in an attempt to identify any possible facilities that could be contributing to the environmental contamination near the Horseshoe Road Site. The TRI is compiled by USEPA and is based on estimated annual releases of toxic chemicals to the environment (air, water, soil, or underground injection) provided by certain industries.

The TRI search for the years from 1987 to 1990 did not list any reported emissions of chemicals that could contribute to ar be confused with the contamination caused by the Horseshoe Road Site.


To determine whether nearby residents are exposed to contaminants migrating from the site, NJDOH evaluates the environmental and human components that lead to human exposure. This pathways analysis consists of five elements: (1) a source of contamination; (2) transport through an environmental medium; (3) a point of human exposure; (4) route of human exposure; and (5) an exposed population.

NJDOH classifies exposure pathways into three groups: (1) "completed pathways", that is, those in which exposure has occurred, is occurring, or will occur; (2) "potential pathways", that is, those in which exposure might have occurred, may be occurring, or may yet occur; and (3) "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. A summary of all the pathways for the Horseshoe Road site and the contaminants of concern summarized in Table 7.


HRS* Groundwater Residences
Skin Contact
Residents Past
HRS Waste
HRS Soil on-site
Skin Contact
HRS Waste
HRS Air on-site
Inhalation Tress-
HRS Waste
HRS Sediment
Surface Water
Skin Contact
Raritan River
HRS Sediment
Surface Water
Biota Ingestion Consumers
of Biota

* Horseshoe Road Site
** Pending Remediation

A. Completed Pathways

There are no known completed pathways at the Horseshoe Road Site.

B. Potential Pathways

    Residential Well Pathways

It is likely that groundwater under and in the vicinity of the Horseshoe Road Site have been contaminated by the site. Possible contaminants include: VOCs, PAHs, heavy metals (e.g., lead and mercury), and pesticides.

Past exposures of several residents living near the Horseshoe Road Site may have occurred prior to the introduction of a municipal water supply sometime during the 1960's (personal communication, Sayreville Water Company). Current and future exposures are possible for any local residents still using well water for non-drinking purposes such as showers and dishwashing, and through direct contact with VOC's released during activities such as handwashing. Local officials were unable to confirm or deny the possibility that some residential wells might still be in service. Past documents on the site have made reference to at least two of these residential wells within 1/2 mile of the site. Since little is known of the groundwater under the site, the gradient of groundwater has not been characterized. It is assumed, however, that the flow would generally be away from these wells and towards the Raritan River.

    Soil Pathways

Soil sampling (0-12") at the Horseshoe Road Site has demonstrated a considerable level of contamination. Numerous contaminants were detected, above ATSDR's comparison values, including VOC's and phenols, PAH's, heavy metals, PCB's and pesticides.

It is important to note that since the soil samples were taken at 50 foot intervals on a grid, they may not be accurate representations of area contamination. Actual contaminant levels may be higher or lower. While calculating exposure doses for soil exposure, the ATSDR prefers to use surface soil taken from the 0 - 3" level. Using soil data from the 0 -12" level is less representative of surface soil exposure, depending on the amount of soil contaminant migration to lower soil levels.

The heaviest contamination at this site appears to be closer to the buildings and inside the fences. There is, however significant areas of contamination outside restricted areas. Of particular concern in these accessible areas are: PCB's (660 ppm); pesticides, eg. DDD (160 ppm), DDT (450 ppm), aldrin (190 ppm), endosulfan (380 ppm), and heptachlor (18 ppm); PAH's, eg., benzo(g,h,i)perylene (350 ppm); and Metals, e.g., arsenic (1,971 ppm), chromium (2,900 ppm), and lead (471 ppm).

Because the aforementioned contaminated areas are outside of the two fenced in zones, it is possible that site trespassers, such as hunters, would be exposed to contaminants at levels of public health concern. Exposures could occur following direct skin contact with contaminated soil or through inhalation of dust created by vehicles, particularly during dry weather.

On site workers and nearby residents may potentially exposed to airborne soil and dust released during site remediation activities. The number of people who may be potentially exposed to contaminated soil at or near the site is unknown.

    Surface Water and Sediments

The site has been heavily contaminated, as documented by a history of spills, poor housekeeping practices, illegal disposal and unpermitted wastewater discharges. As previously noted, surface water runs off the site into the Raritan River. In addition, there is documentation of hazardous chemicals being dumped directly into the river.

No surface water sampling results were available for review, but it would be reasonable to conclude, given the history and conditions of the site, that surface water and sediments of the Raritan River have been adversely effected by the site.

Recreational use, e.g. boating and fishing, in this portion of the Raritan River has been confirmed by the Local Health Department. These types of activities could lead to potential exposures, mostly through dermal contact, to site related contaminants, although it would be unlikely they would be exposed at levels of public health concern.

As part of their justification for requesting a removal action at the Sayreville Pesticide Dump section of the site, the USEPA did some limited sediment sampling in the drainage area leading from this area.4 These data showed significant contamination with organic compounds and heavy metals, Table # 6.


Potential past, present, and future exposures to site contaminants that may bioaccumulate in fish, and other aquatic life, is possible for individuals who have eaten or eat fish and/or crustacea from the Raritan River.

Several of the site related contaminants, e.g. lead, mercury, and PCBs, have a moderate to high potential for bioaccumulation in fish. Fish sampling is necessary to eliminate this pathway. Also, since many fish are bottom feeders, they come in close contact with possibly contaminated sediments. This pathway can not be fully evaluated until additional sediment and biota data are available.


A. Toxicologic Evaluation

This section contains discussion of the health effects in persons exposed to specific contaminants, evaluations of State and local databases, and address specific community health concerns. Health effects evaluations are accomplished by estimating the amount (or dose) of those contaminants that a person might come in contact with on a daily basis. This estimated exposure dose is than compared to established health guidelines. People who are exposed for some crucial length of time to contaminants of concern at levels above established guidelines are more likely to have associated illnesses or disease.

Health guidelines are developed for contaminants commonly found at hazardous waste sites. Examples of health guidelines are the ATSDR's Minimum Risk Level (MRL) and the USEPA's Reference Dose (RfD). When exposure (or dose) is below the MRL or RfD than non-cancer, adverse health effects are unlikely to occur.

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

The toxicological effects of the contaminants detected in the environmental media have been considered singularly. The cumulative or synergistic effects of mixtures of contaminants may serve to enhance 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, its pharmacokinetics in children and adults, and its toxicity in children and adults.

    Trespassers on the site

Although there are presently no completed human exposure pathways at the site, trespassers constitute a potential exposure pathway.

The NJDOH has determined that trespassers on the Horseshoe Road site may be exposed to several contaminants at levels of public health significance. It is very unlikely that very young children would trespass on the site, mostly due to the remoteness of the site. It is likely that trespassers would be either adults or older children (weighing > 35 Kg). Since site trespassers would be, unlikely to either inadvertently or intentionally come in contact with contamination inside the two fenced areas, the contaminant levels used in this section reflect levels found outside the fenced areas were access is possible.

Because of the large diversity of compounds present, this toxicological evaluation is organized by groups of contaminants (e.g., PCB's) or by a representative compound from a group which presents the highest potential for adverse health effects. In addition, selection of contaminants was also based on the location and concentration found on the site.

To estimate exposure doses of persons hunting and/or trespassing on the site, the following assumptions were made. It was assumed that the site was visited by children (weighing 35 kg), 2 times per week, for a period of four months per year, and that they would ingest 200 milligrams (mg) of soil during each visit.


As reported earlier in this public health assessment, trespassers at the Horseshoe Road site may be exposed to PCB's at a maximum concentration of 660 ppm. The estimated exposure dose is approximately equal to ATSDR's chronic oral MRL of 0.00002 mg/kg/day. Exposure doses were well below the no observed adverse effect levels (NOAELs) for chronic oral exposure in animals (for effects other than cancer), cited in the ATSDR Toxicological Profile for PCB's.

PCB's are carcinogenic in animals and potentially carcinogenic in humans; the USEPA classifies PCB's as a probable human carcinogen. Based upon the maximum concentration of PCB's found in soils outside the fenced areas at the site, the lifetime excess cancer risk (LECR) associated with oral exposure to PCB's would present no apparent risk of cancer.

PAH's - (benzo[g,h,i]perylene)10

Trespassers at the Horseshoe Road site may be exposed to benzo(g,h,i)perylene at a maximum concentration of 350 ppm.

Presently there is no MRL or RfD for chronic oral exposure to benzo(g,h,i)perylene. However, exposure doses calculated from the maximum reported concentration of benzo(g,h,i)perylene (350 ppm) were below the No Observed Adverse Effects Level (NOAEL) for animal studies, intermediate exposure (15-365 days) presented in the ATSDR Toxicological Profile for this chemical. At such concentrations, it is not likely that non-carcinogenic adverse health effects would occur.

Several PAH's have been shown that they may reasonably be anticipated to be carcinogens. Benzo(g,h,i)perylene, however, was found by the USEPA to be not classifiable as a human carcinogen.


Trespassers at the Horseshoe Road site may be exposed to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) at a maximum concentration of 450 ppm. The estimated exposure dose is below USEPA's chronic oral RfD of 0.0005 mg/kg/day. Exposure doses are less than the no observed adverse effect levels (NOAELs) for chronic exposure in animals (for effects other than cancer) cited in ATSDR's Toxicological Profile for this chemical.

Studies have shown that DDT is carcinogenic in animals; the USEPA classifies DDT as a probable human carcinogen. Based upon the maximum concentration found in soils outside the fenced areas at the site and resultant estimated exposure doses, the lifetime excess cancer risk (LECR) associated with oral exposure to DDT presents an insignificant increased risk of cancer.

METALS (arsenic)12

Trespassers at the Horseshoe Road site may be exposed to arsenic at a maximum concentration of 1,971 ppm. The estimated exposure dose is below the chronic oral MRL of 0.0003 mg/kg/day. Exposure doses do not exceed the no observed adverse effect levels (NOAELs) for chronic exposure in animals (for effects other than cancer) cited in the ATSDR Toxicological Profile for this element.

Studies have shown that arsenic is a human carcinogen, and is so classified by the USEPA. Based upon the maximum concentration found outside the fenced areas at the site, the lifetime excess cancer risk (LECR) associated with oral exposure to arsenic present an insignificant increased risk of cancer.

B. Health Outcome Data Evaluation

Health outcome data for the Horseshoe Road Site were not evaluated. Although potential exposure pathways for on-site contaminants have existed in the past, primarily through contact with contaminated groundwater, only a few residences were potentially exposed. Available databases would not yield observable results for a study population of this size.

Should the ATSDR and the NJDOH decide to do so, the health status of those residents whose wells were effected by site related contamination may best be determined by individual case investigation.

C. Community Health Concerns Evaluation

Community health concerns at the Horseshoe Road Site have been minimal, possibly due to the sites remoteness and the limited number of residents living near the site.

The ATSDR and the NJDOH will review and evaluate any community health concerns which may arise. Current remedial work at the site and the release of the preliminary health assessment may generate interest among the public during the public comment period. Any comments received will be addressed in a subsequent responsiveness summary.

    Public Comment Period

The New Jersey Department of Health (NJDOH) conducted a comment period for the Preliminary Public Health Assessment for the Horseshoe Road site from September 23, 1994 to October 28, 1994. The Preliminary Public Health Assessment was placed in local repositories to facilitate commentary and reaction from the public at large. Additionally, the Public Health Assessment Addendum was circulated to the Middlesex County Health Department for the purpose of soliciting commentary by local health officials.

No comments regarding the Horseshoe Road site were received by the NJDOH during the comment period.

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