Fact Sheet Spring 1998: Human Health Evaluation and Ecological Risk Assessment Regarding PCB Contamination in Pittsfield, MA
The U.S. Environmental Protection Agency's New England Office recently completed risk evaluations on human health and ecological impacts on a two-mile section of the Housatonic River. The two evaluations document the widespread prevalence and high concentrations of PCBs in and along the two-mile section of river and the significant human health and environmental risks from exposure to those PCBs.
Among the findings:
Young children and teenagers playing in and near portions of the river face noncancer risks that are 200 times greater than EPA considers safe. Noncancer effects from PCBs may include liver and nervous system damage and development abnormalities, including lower IQs.
Teenagers growing up near portions of the river face a 1 in 1,000 cancer risk due to exposure to contaminated riverbank soils.
Fish collected in the river had PCBs concentrations of up to 206 parts per million, among the highest levels ever found in the United States and 100 times higher than the limits set by the U.S. Food and Drug Administration.
91 of 93 sediments samples taken in the Upper Reach of the river showed the presence of PCBs.
These risk evaluations, which were peer reviewed and endorsed by EPA Headquarters, support EPA's position that the entire two-mile section of river may present an imminent and substantial endangerment to human health and the environment. These evaluations justify removal actions for the Upper Reach section of the river. The actions also are based on data showing that previously cleaned-up floodplain areas are being recontaminated by PCBs from the river during routine flooding.
HUMAN HEALTH RISK EVALUATION
The Human Health Risk Evaluation, co-authored by the Massachusetts Department of Environmental Protection, examined cancer and noncancer risks to humans based on PCB contamination levels in river sediments, riverbank soils and backyard soils as well as consumption of fish caught in the river.
The risk evaluation focused primarily on health risks from short-term PCB exposures - less than 10 years of exposure. The study assumed exposure to PCB-contaminated sediments and soils when residents were walking, playing and sitting in and alongside the river. The exposure is primarily through skin contact with PCB-contaminated soil and sediments, and incidental ingestion of dust.
The health risk evaluation concludes that there are significant human health risk along the entire two-mile stretch of river. Some of the highest human health risks are in the lower 1½ miles of the Upper Reach. This is due both to high PCB levels in this area- average PCB levels in shallow river sediments, for example, are nearly five times higher downstream than in the first ½-mile section - and higher exposure rates since portions of the lower section of river are more residential and more accessible than the top ½-mile section.
Among the highlights in the human health risk evaluation:
Noncancer Risks - Potential Effects such as Reproductive and Development Abnormalities (such as Lower IQs), Liver Damage and Adverse Impacts on Nervous Systems
Young children playing for just one summer in the river in portions of the lower section - specifically, a ½-mile area between the Elm Street and Dawes Avenue Bridges - face noncancer risks 200 times higher than the hazard-index level EPA considers safe. This estimated risk assumes exposure to PCB-contaminated surface sediments in the river. PCB levels in this area averaged 89 parts per million, nearly five times higher than the 19 ppm average in the top ½ mile section between Newell and Lyman Streets.
Children, ages 5 to 12, who live or play alongside the river between the Elm Street and Dawes Avenue Bridges face noncancer risks 90 times higher than the hazard-index level EPA considers safe. This estimated risk assumes springtime and summertime exposure to PCB-contaminated riverbank soils and floodplain soils.
Teenagers who live or play alongside the river face noncancer risks 200 times higher than hazard-index level EPA considers safe. This estimated risk assumes springtime and summertime exposure to PCB-contaminated soils while walking and playing on the riverbanks in the vicinity of the GE plant between the Newell Street and Elm Street Bridges.
A nine-year-old child who consumes one meal of fish from the Housatonic River each week for just one summer faces noncancer risks about 900 times higher than the hazard-index EPA considers safe.
Some sections of the two-mile stretch of river pose an increased cancer risk beyond levels that EPA considers acceptable. As an example, teenagers who grow up alongside the river - in the vicinity of the Newell Street and Elm Street Bridges - face a 1 in a 1,000 cancer risk due to their exposure to contaminated riverbanks soils.
Evaluation of Human Health Risks from Exposure to Elevated Levels of PCBs in Housatonic River Sediment, Bank Soils and Floodplain Soils in Reaches 1-2 to 4-6 (Newell Street to the confluence of the East and West Branches), May 14, 1998 (PDF) (58 pp, 3.1 MB, about PDF)
ECOLOGICAL RISK ASSESSMENT
The Ecological Risk Assessment evaluated the environmental impacts PCBs are having on water quality and aquatic species along the two-mile Upper Reach section of the river. The assessment was based on recent surface water, sediments and fish data collected by GE, EPA and the U.S. Geological Survey.
Of 93 sediment samples taken from the two-mile section of river, 91 showed the presence of PCBs, with the highest concentrations being 905 parts per million. Sixty-two of the 93 samples had PCB concentrations that would cause severe impacts on most aquatic species.
Fish collected in the river had PCB concentrations of up to 206 parts per million. Based upon effects observed in other scientific studies, the ecological assessment concludes that the PCB levels would have adverse reproductive impacts on fish and on animals that rely heavily on fish in their diet such as heron and otter.
The EPA's Ambient Water Quality Criteria (AWQC) for PCBs in the middle part of the two-mile river section was exceeded in nine out of 10 months during a recent sampling period in 1996 and 1997.