Contact: Eliot Hurwitz FOR IMMEDIATE RELEASE
(301) 713-3066 9/27/95
After eight years of sampling mussel and oyster tissues, scientists have concluded that contamination of U.S. coastal areas may be decreasing as a result of environmental regulations that have either banned or curtailed toxic chemicals such as DDT, according to a report released today by the Commerce Department's National Oceanic and Atmospheric Administration.
The report, "Recent Trends in Coastal Environmental Quality: Results from the Mussel Watch Project," details results from analyzing chemical concentrations found in mussel and oyster tissues collected every year since 1986 and gives an objective measure of the effectiveness of federal environmental policy.
The Mussel Watch Project collects these mollusks once a year at more than 240 sites nationwide. The shellfish are analyzed for over 70 polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated pesticides, butyltins, and toxic trace elements, such as copper, cadmium and lead. Sediments at the test sites are also regularly analyzed for chemical contaminants, and shellfish from selected locations are analyzed for radionuclides.
"There are many more decreases than increases in chemical concentrations [in coastal regions] between 1986 and 1993," the report said.
"Decreasing trends are not unexpected," the report said. "All the monitored chlorinated hydrocarbons have been banned for use in the United States and tributyltin has been banned as a biocide on recreational boats. For cadmium and arsenic there have been decreases in their use."
"The Mussel Watch program is a prime example of how NOAA fulfills its mandate to monitor and assess the state of our coastal environment," said NOAA Administrator D. James Baker. "We are committed to providing decision makers at the federal, state and local levels with solid, science-based information on which to base important policy decisions." All of these substances can be acutely or chronically toxic to marine life and to humans under some conditions.
For other chemicals there is no strong evidence, on a national scale, for either an increasing or decreasing trend, and lead is the only chemical showing concentrations in excess of public health guidelines. However, there are some sites where chemicals are at high concentrations (though not necessarily threatening to marine organisms or man) and may be increasing, the report said.
The report also identifies locations with high concentrations of contaminants, and discusses both human-induced and possible natural explanations for these findings.
Prepared by NOAA's Office of Ocean Resources Conservation and Assessment, the report states, "It is comforting and expected that where trends exist they are, by far, mostly decreases. Increasing trends are uncommon and most . . . may only be chance sequences."
###Note to Editors: Call Eliot Hurwitz, (301) 713-3066, for a copy of the report.