Levels of pesticides and other toxic chemicals in US coastal waters are generally decreasing, McClatchy reports. A 20-year study by the National Oceanographic and Atmospheric Administration's Mussel Watch looked at levels of 140 chemicals and found decreasing trends. Laws banning many of the chemicals were passed in the 1970s, but the long process of their disappearance from the environment continues.
"Different regions have different stories," says Gunnar Lauenstein, the program's lead scientist. "But when you look at all the numbers and evaluate them statistically, it shows that on a national basis, concentrations are going down."