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U.S. Coastal Waters Getting Cleaner
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.
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’
Gunnar Lauenstein, the head scientist of the Mussel Watch program of the National Oceanographic and Atmospheric Administration, which conducted the study, said “Different regions have different stories … with some contaminants increasing in some regions.” But she went on to say, “when you look at all the numbers and evaluate them statistically, it shows that on a national basis, concentrations are going down.”
Source: The Hartford Courant
Historical Context: Environmental protection since the 1970s
In 1945, the Fish and Wildlife Service reported that, although DDT was an important tool in controlling insects, it could cause “considerable damage to wildlife, beneficial insects, and indirectly to crops.” The agency urged caution because of “our knowledge and our ignorance” of the full range of DDT’s effects.
Source: The Fish and Wildlife Service
It took three years of study before the U.S. government concluded that the use of DDT should stop. Although the Environmental Protection Agency decided to prohibit DDT in June 1972, the full ban was delayed nearly six months to ease the transition to substitute pesticides for farmers.
Source: The Environmental Protection Agency
The EPA was created in 1970. Two years later DDT was banned and the Clean Water Act was passed “limiting raw sewage and other pollutants flowing into rivers, lakes, and streams.” The Web site of the EPA provides a timeline of important dates since the agency’s formation.
Source: Environmental Protection Agency
Opinion & Analysis: ‘Earth Day, Then and Now’
In 2000, an article in Reason Magazine appeared 30 years after the celebration of the first Earth Day. Ronald Bailey argued that the doomsday scenario many predicted had not come true, and, in fact, the “planet’s future has never looked better.” Bailey credits technology for much of the success, and 30 years from now, a “richer world will be much better able to cope with any environmental problems that might crop up.”
Source: Reason Magazine
Related Topics: Penguins, sea lions and fish
Although the United States banned the use of DDT in 1973, the levels of the pesticide found in Antarctic penguins remains the same. Penguins in the Arctic appear to have benefited from the ban, but in the Antarctic penguins, “Scientists blame the continued presence of DDT on the melting of glacial ice.”
Source: findingDulcinea
A Feb. 28 article from findingDulcinea reported on a study demonstrating the long-term adverse effects estrogen from pollutants can have on fish populations. “The pollution killed many fish and disrupted reproduction in others. The sperm count of male minnows fell, with some even beginning to produce eggs in their testes,” according to Science Daily.
Source: findingDulcinea
Six sea lions found dead in the northwest United States highlighted the controversial federal policy that permitted the killing of sea lions to protect the dwindling Pacific salmon populations.
Source: findingDulcinea
Reference: A long-term look at U.S. ocean waters, DDT in the environment
The Mussel Watch program of the National Oceanographic and Atmospheric Administration released the study, available in PDF format, covering the years 1986 through 2005. It is “the longest running estuarine and coastal pollutant monitoring effort conducted in the United States that is national in scope each year.”
Source: Center for Coastal Monitoring and Assessment
3D-Chem.com offers an interactive, three-dimensional model of the DDT molecule and facts about its environmental impact. The use of DDT was banned in the United States in 1973, although it is still in use in some other parts of the world. “The biological half-life of DDT is about eight years; that is, it takes about eight years for an animal to metabolize half of the amount it assimilates,” the site explains. But the buildup of DDT in waters is reversible process. The EPA reported a 90 percent reduction of DDT in Lake Michigan fish by 1978 as a result of the U.S. ban.
Source: 3D Chem.com
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