Coastal Study Shows Chemical, Pesticide Levels Going Down
Posted on: Monday, 12 May 2008, 09:00 CDT
Some good news from the government scientists who study pollution in U.S. coastal waters: A newly released 20-year study shows overall levels of pesticides and industrial chemicals are decreasing.
The Mussel Watch program of the National Oceanic and Atmospheric Administration examined levels of 140 chemicals from 1986 to 2005 in coastal areas and estuaries of Alaska, Hawaii, Puerto Rico, the East and West coasts, the Gulf of Mexico and the Great Lakes. Mussel Watch is the longest continuous contaminant-monitoring program in U.S. coastal waters.
Gunnar Lauenstein, an oceanographer who's the lead program scientist , said the levels are continuing to decrease many years after environmental laws were enacted in the 1970s.
"Different regions have different stories," Lauenstein said, with some contaminants increasing in some regions.
But, Lauenstein said, "when you look at all the numbers and evaluate them statistically, it shows that on a national basis, concentrations are going down."
The pesticide DDT shows significant decreasing trends around the country, even in Southern California, which had the heaviest concentrations, Lauenstein said. Industrial chemicals, such as PCBs, a material used in electrical products, including transformers, also show declines.
PCBs are transported in the atmosphere over long distances. The report said that most organic contaminants do not have natural sources, but they are distributed everywhere.
Some problems highlighted in the report include oil-related compounds from motor vehicles and shipping, which continue to flow into the waters. NOAA also is studying flame retardants and plans to release findings this year about the effects they have on marine and human health.
The report also found that levels of tributyl-tin, a compound that was used to kill marine organisms on boat hulls, were declining. The compound affected not only the organisms it was meant to kill but also other marine and fresh-water life. Tributyl-tin was regulated in the late 1980s and its use is also decreasing nationally.
Under the Mussel Watch program, scientists collect mussels every year at about 300 sites and measure the contaminants in their fatty tissue.
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The report is available at http://nsandt.noaa.gov
Source: Virginian - Pilot
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