MDE Issues Fish Consumption Advisory for Tidal Potomac River

Press Release

Maryland Department of the Environment
Quentin Banks

MDE Issues Fish Consumption Advisory for Tidal Potomac River

BALTIMORE (April 19, 1999) – The Maryland Department of the Environment (MDE) today announced that large channel catfish, eel and carp caught in the tidal Potomac between the Woodrow Wilson Bridge and a line between Smith Point, Maryland and Brent Point, Virginia, may be contaminated with polychlorinated biphenyls (PCBs), a suspected human carcinogen. The advisory pertains to only these species and therefore the vast majority of Chesapeake Bay seafood continues to provide a safe and healthy food that is high in protein and low in fat.

To protect public health, MDE issued a three part advisory: first, the general public should limit the consumption of large channel catfish (greater than 18-inches in length) from this area to not more than one 8-ounce meal per month. Second, although there is no recent data to support a formal advisory against eating large eel and carp, MDE cautions against consuming too many of these fish caught in the affected waters, because the feeding habits of carp and eel are similar to those of channel catfish. Smaller channel catfish and other species are not affected by the advisory. Third, infants, children and women of childbearing age are cautioned to avoid eating these fish because they are more susceptible to the effects of PCB contamination. MDE advises that these fish should not be used as a substantial part of the daily diet. This advisory is limited in nature, directed toward recreational fishermen, and is specific to the three species identified. Commercial fisheries are not affected.

To further reduce the health risk, it is recommended that individuals who continue to consume these fish should remove the skin, dark meat and the belly flap because PCBs concentrate in the fatty portions of the fish. The fish should be broiled or baked in a tray that allows the fat to run off and the drippings discarded.

The advisory is based on the possibility that long-term consumption of PCB-contaminated fish may increase the risk of cancer in humans. Studies have shown that PCBs have the potential for causing cancer in laboratory animals. Although studies have not conclusively demonstrated that PCBs cause cancer in humans, EPA considers the evidence suggestive and categorizes PCBs as probable human carcinogens.

The increased risk that is estimated from a lifetime of fish consumption at the rate of one meal per month is less than 10 additional cancer cases in 100,000 people. To give this value some perspective, it can

be compared to a lifetime cancer risk for someone sharing an office with a smoker, which is 700 in 100,000.

Although preliminary data are limited, reduced consumption of American eel and carp is recommended because these two species are have feeding habits similar to those of channel catfish. MDE plans to investigate these two species more thoroughly. When these data become available, the department will examine the findings and issue a revised advisory as appropriate.

PCBs, which have not been produced in the United States since 1977, have been used as coolants and lubricants in a variety of electrical applications including transformers and capacitors. PCBs remain in the environment because they do not readily decompose. Instead, they bind to sediments where sediment-dwelling organisms can be exposed to and accumulate them. Fish that consume these organisms will in turn accumulate the PCBs. Larger fish tend to accumulate more of these materials than smaller ones.

Based on currently available information, these recommended consumption levels will protect public health. MDE is collecting additional data to refine its risk estimates and may modify this preliminary advisory when these data become available. The Department will attempt to identify sources and work cooperatively with surrounding jurisdictions to develop appropriate management plans.