Finally: Good News about the Environment

According to NOAA (The US National Oceaonagraphic and Atmospheric Agency), a 20-year study shows that overall contaminant levels in coastal waters of the US are down. US environmental laws, enacted in the 1970s, are likely responsible for this reduction in toxic chemicals, and while there are certainly continuing problems, it's safe to say that there has also been continuing improvement.

The study, called "Mussel Watch" - as it, well, watches mussels - has been under way since 1986. The findings are the result of monitoring efforts that currently analyze 140 different chemicals along U.S. coasts and estuaries, including the Great Lakes. Tissue samples have been kept frozen (rather than researchers simply relying on collected data), so that side-by-side comparisons could be made from these filter-feeder's 'snapshots' of the coastal water condition. This long-sighted approach allows scientists to look back and study pollutants we haven't even identified yet, and is by far the most comprehensive study of its kind.

“It’s interesting to note that pesticides, such as DDT, and industrial chemicals, such as PCBs, show significant decreasing trends around the nation, but similar trends were not found for trace metals,” said Gunnar Lauenstein, manager of the NOAA Mussel Watch program. "What is of concern is that there are contaminants that continue to be problematic, including oil-related compounds from motor vehicles and shipping activities."

"We need to ensure the safety of our coastal waters for the rich resources they provide," noted John H. Dunnigan, NOAA assistant administrator of the National Ocean Service. "This program shows that although our coasts are under tremendous pressure, policymakers and the public are able to work together to produce positive results."

Significant findings from this report include the following:

• Decrease in DDT - the pesticide
• Decrease in PCBs - from manufacturing
• Decrease in TBT - tributyl-tin from old-style antifouling paint
• Continuing problem with oil-related compounds (For example, PAH levels following the 2007 Cosco Busan oil spill in San Francisco Bay showed concentrations at the monitoring site near the spill were the highest ever recorded.)

Currently the study is focusing on flame retardants known as PBDEs. While only recently identified as a new class of contaminants, the long-term buildup of these chemicals can be studied immediately because of the frozen tissue samples. In fact, NOAA plans to issue a report on flame retardants in coastal waters later this year.

photo credits: Michael Dawes, Paul Gengenbach