|
Birth control may be harming state's salmon - Synthetic estrogen in water seems to affect reproduction By
LISA STIFFLER 5/6/03 Birth-control pills can curb the reproduction of more than just the women taking them. Western Washington scientists have found that synthetic estrogen -- a common ingredient in oral contraceptives -- can drastically reduce the fertility of male rainbow trout. The man-made compounds are showing up in waterways around the nation -- pumped into rivers, lakes and Puget Sound with water from sewage-treatment plants. And they're being found at levels that can harm fish, possibly even this region's struggling salmon populations. "It is disturbing in the extreme," said Kaitlin Lovell, salmon-policy coordinator for Trout Unlimited in Portland. The research by scientists at the Battelle Marine Sciences Laboratory in Sequim is unique for its focus on trout, which is related to salmon, and for looking at reproductive effects on adult fish rather than juveniles. How fish are affected by such chemicals in the wild remains unclear. "It's something we're concerned about," said Irvin Schultz, a senior research scientist at the lab. In the experiment, adult trout in caged pens were exposed to ethynylestradiol, a synthetic estrogen. After two months of exposure, the fish were spawned with a healthy female. Researchers discovered that the exposed trout were half as fertile as fish kept in clean water. The research by the government-funded lab is outlined in this month's issue of the journal Environmental Toxicology and Chemistry. The findings are likely to fuel concerns about the environmental
effects of chemicals that aren't being filtered out by sewage plants,
including pharmaceuticals and pesticides that can mimic hormones.
There are no standards for how much synthetic estrogen and other hormones can be released in sewage and wastewater, and treatment plants generally do not monitor for it. The Environmental Protection Agency is studying which of these compounds have harmful effects. Then the next step will be testing for their presence in waste water. New regulations could follow. Although trout don't have the ability to rid themselves of the synthetic hormones, Schultz doesn't think it poses a serious threat to people eating the fish because the levels in the environment are low. There are some concerns about wastewater that is being recycled back into the environment, particularly in desert areas, where it might mix with groundwater that could be used for drinking. An official with King County said there is little cause for concern about human risks locally. New sewage-treatment facilities are looking into special membranes that will help pull some of these contaminants out, said John Smyth, an official with King County's technology-assessment program. It's currently being considered for the planned Brightwater treatment plant that will serve King and Snohomish counties. "Agencies like us all over the country are trying to figure out ways to tackle this thing," Smyth said. The researchers in Sequim tested the effects of synthetic estrogen at three different levels. The scientists were surprised that even the lowest level -- 80 times lower than levels measured in the wild -- had an effect on fertility. The scientists would like to do more tests to identify the smallest concentrations that can harm fish. They were unable to figure out how the estrogen was causing the reduction in fertility. It appears not to affect the swimming ability of sperm. With so many unanswered questions about what compounds are getting into the environment, their effects and how to get them out of the wastewater, environmentalists and scientists are concerned. Said Trout Unlimited's Lovell, "If anything, these problems are only going to get worse before they get better." |