Assessment and Remediation of Contaminated Sediments (ARCS) Program

BASELINE HUMAN HEALTH RISKS RESULTING FROM PCB CONTAMINATION AT THE SHEBOYGAN RIVER, WISCONSIN, AREA OF CONCERN

by

Judy L. Crane
Asci Corporation
Athens, Georgia 30605

Project Officer
Robert B. Ambrose, Jr.
Environmental Research Laboratory
Athens, Georgia 30613

ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ATHENS, GEORGIA 30613

ABSTRACT

The Assessment and Remediation of Contaminated Sediments (ARCS) program, a 5-year study and demonstration project relating to the control and removal of contaminated sediments from the Great Lakes, is being coordinated and conducted by the U.S. Environmental Protection Agency's (EPA) Great Lakes National Program Office (GLNPO). As part of the ARCS program, baseline human health risk assessments are being performed at five Areas of Concern (AOCs) in the Lakes region. The Sheboygan River, located in eastern Wisconsin, is one of AOCs.

In this report, exposure and risk assessment guidelines, developed for the EPA Superfund program, have been applied to determine the baseline human health risks associated with direct and indirect exposures to sediment-derived contaminants in the Sheboygan River AOC. These risks were estimated for carcinogenic effects (i.e., probability of an individual developing cancer over a lifetime).

INTRODUCTION

The Assessment and Remediation of Contaminated Sediments (ARCS) program, a 5-year study and demonstration project relating to the control and removal of contaminated sediments from the Great Lakes, is being coordinated and conducted by the U.S. Environmental Protection Agency's (EPA) Great Lakes National Program Office (GLNPO). As part of the ARCS program, baseline human health risk assessments are being performed at five Areas of Concern (AOCs): Ashtabula River, OH; Buffalo River, NY; Grand Calumet River/Indiana Harbor Canal, IN; Saginaw River, MI; Sheboygan River, WI. This risk assessment will focus on the baseline human health risks resulting from exposure to sediment-derived contaminants at the Sheboygan River.

The Sheboygan River/Harbor AOC includes approximately 22.5 km of the Sheboygan River and the entire Sheboygan Harbor (47.5 hectare) (Figure 1). This area was designated as a Superfund site in 1985 due to widespread contamination of the sediments and fish by PCBs. In addition, the sediments have been contaminated with several heavy metals (e.g., cadmium, chromium, lead, mercury, nickel, and zinc). Due to the level of PCB contamination in the fish, a "do not eat" fish advisory has been issued by the Wisconsin Department of Natural Resources (DNR) and the Wisconsin Division of Health for all resident fish species, including smallmouth bass, walleye, and panfish as well as for migratory species such as chinook salmon and steelhead trout. Despite these fish advisories, some people continue to consume fish from the Sheboygan River and Harbor.

The extent of contamination at the AOC has been described in detail in the Remedial Investigation/Enhanced Screening (RI/ES) report for the Sheboygan River and Harbor (Blasland and Bouck Engineers, 1990). A human health endangerment assessment, conducted as part of the RI/ES report, indicated that three long-term exposure scenarios resulted in "unacceptable" carcinogenic risks (i.e., cancer risks greater than the 10^[-4] to 10^[-7] range):

• Dermal exposure to river sediments containing the maximum observed PCB concentrations
• Ingestion of certain fish species that contained PCB concentrations greater than the FDA limit (i.e., 2.0 mg/kg)
• Ingestion of certain waterfowl species contained PCB concentrations greater than 4 mg/kg in edible portions

The most highly contaminated sediments in the Sheboygan River were dredged between 1989 and 1991 under two phases. Under the first phase, dredged sediments were placed in a Pilot Confined Treatment Facility (CTF) (Eleder, 1991); the CTF is being used to study the effectiveness of enhanced natural biodegradation for treatment of PCBs. The second phase was implemented under a removal Action; these sediments have been stored temporarily in a tank until a decision can be made in the Record of Decision as to their final disposal. In addition, less contaminated sediments have been armored in place. A monitoring program has been designed and implemented to assess the effectiveness of the removal, armoring, and biodegradation of sediments. A fish monitoring program was begun in 1989 and continues today. As part of the monitoring program, data were collected during 1991 to determine total PCB levels in floodplain soils and in four species of fish.

Rather than duplicate the effort of the RI/ES endangerment assessment, this baseline risk assessment for the ARCS program sought to update the endangerment assessment with new data. Exposure and risk assessment guidelines, developed for the EPA Superfund program, were used to estimate the carcinogenic risk from exposure to sediment-derived contaminants (i.e., PCBs).

REFERENCES [for Introduction]

Blasland and Bouck Engineers. 1990. Remedial Investigation/Enhanced Screening Report Sheboygan River and Harbor. Final Report for Foley & Lardner/Tecumseh Products Company.

Eleder, B.L. 1991. Sheboygan River and Harbor, Sheboygan, Wisconsin. In: Biological Remediation of Contaminated Sediments, with Special Emphasis on the Great Lakes, C.T. Jafvert and J.E. Rogers (eds.). pp. 50-54

Wisconsin DNR. 1990. Information Bulletin (December 6, 1990). Department of Natural Resources, Southeast District Headquarters, Milwaukee, WI.

LIST OF FIGURES

Figure

1. Sheboygan River AOC boundaries

LIST OF TABLES

Table

1. Generic Equation for Calculating Chemical Intakes (USEPA, 1989a)
2. Mean PCB Concentrations in Four Species of Fish Collected from the Sheboygan River
3. Equation Used to Estimate Contaminant Intakes Due to Ingestion of Fish
4. Parameters Used in Estimating Contaminant Intakes Due to Ingestion of Fish from the Sheboygan River
5. Equation used in Estimating the Absorbed Dose of PCBs due to Dermal Contact with Floodplain Soils
6. Parameter Values Used in Estimating the Absorbed Dose Due to Dermal Contact with Floodplain Soil (Numbers in Parentheses Correspond to Reasonable Maximum Exposures)
7. Carcinogenic Risk from Consuming Sheboygan River Fish, Typical Exposure, FI = 0.05
8. Carcinogenic Risk from Consuming Sheboygan River Fish, Reasonable Maximum Exposure, FI = 0.1
9. Carcinogenic Risk from Consuming Sheboygan River Fish, Subsistence Exposure, FI = 0.2
10. Estimated Carcinogenic Risk Due to Dermal Exposure to Contaminated Floodplain Soils, Typical Exposure Scenario
11. Estimated Carcinogenic Risk Due to Dermal Exposure to Contaminated Floodplain Soils, Reasonable Maximum Exposure Scenario

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