U.S. Coastal Waters Getting Cleaner

May 13, 2008 10:43 AM
by Josh Katz
A new study shows coastal waters have fewer contaminants than in the 1970s, likely due to the Clean Water Act and a ban on the insecticide DDT.

30-Second Summary

The research, conducted by the Mussel Watch program of the National Oceanographic and Atmospheric Administration, tested the levels of 40 chemicals in U.S. coastal waters from 1986 to 2005.

The project was the “longest continuous, nationwide contaminant monitoring program in U.S. coastal waters,” according to the Center for Coastal Monitoring and Assessment.

In the 1970s, the U.S. passed a string of environmental laws to protect the environment, including the Clean Water Act and a ban on the highly toxic and environmentally persistent insecticide, DDT.

Levels of the pesticide DDT and industrial chemicals like PCBs have decreased notably throughout the United States since that time, the study reveals. Contamination levels have not dropped in every location studied, but there is a reduction on the whole.

In another recent study, researchers found that DDT levels in Arctic penguins have continually decreased since the 1970s. However, DDT levels have remained the same in Antarctic penguins since that time.

Environmental chemist Frank Wania of the University of Toronto Scarborough said, “it is surprising that it [the DDT levels in the Antarctic penguins wouldn’t have declined since the 60s or 70s.” Some scientists believe melting glacial waters may be a source of ongoing DDT contamination.

Headline Link: ‘Coastal Waters Getting Cleaner’

Historical Context: Environmental protection since the 1970s

Opinion & Analysis: ‘Earth Day, Then and Now’

Related Topics: Penguins, sea lions and fish

Reference: A long-term look at U.S. ocean waters, DDT in the environment


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