In the first national study of human drugs in fish tissue, new research finds that fish caught near wastewater treatment plants serving five major cities had residues of pharmaceuticals in them, including drugs used to treat high blood pressure, cholesterol, allergies, depression and bipolar disorder.
The study has prompted the U.S. Environmental Protection Agency (EPA) to expand similar research to more than 150 locations.
“The average person hopefully will see this type of a study and see the importance of us thinking about water that we use every day, where does it come from, where does it go to? We need to understand this is a limited resource and we need to learn a lot more about our impacts on it,” said Bryan Brooks, the study’s co-author and a Baylor University researcher and professor who has published several studies about environmental pharmaceuticals.
While Brooks and other researchers have found that even small concentrations of pharmaceutical residues can harm frogs, fish and other aquatic species, a human would have to consume hundreds of thousands of fish dinners to get even one therapeutic dose, Brooks told the Associated Press.
Brooks and his colleague Kevin Chambliss tested fish obtained from rivers where wastewater treatment plants release treated sewage in Chicago, Phoenix, Dallas, Philadelphia and Orlando. For comparison, they also tested fish from the pristine Gila River Wilderness Area in New Mexico, an area isolated from human pollution sources.
Previous research has confirmed that fish absorb pharmaceuticals because the rivers in which they live are contaminated with trace amounts of drugs that are not removed in sewage treatment plants. A large portion of this contamination is derived from unmetabolized residues of pharmaceuticals that people have taken and excreted. Unused medications dumped down the drain also contribute to the contamination.
Researchers tested fish for 24 pharmaceuticals and 12 chemicals found in personal care products, and discovered trace concentrations of seven drugs and two soap scent chemicals in fish at all five locations. Although the amounts varied, some of the fish had combinations of many of these compounds in their livers.
In contrast, the researchers did not detect any of these chemicals in the reference fish caught in New Mexico.
A similar investigation by the Associated Press had found trace amounts of pharmaceuticals in drinking water provided to at least 46 million Americans.
The EPA has called for further research on the human impact of long-term consumption of trace amounts of medicines in their drinking water, particularly in unknown combinations. Preliminary laboratory studies have shown that cells in humans failed to grow or became unusually shaped in people exposed to certain pharmaceutical combinations found in drinking water.
“This pilot study is one important way that EPA is increasing its scientific knowledge about the occurrence of pharmaceuticals and personal care products in the environment,” An AP report quoted EPA spokeswoman Suzanne Rudzinski as saying.
The completed and expanded sampling for pharmaceuticals and other chemicals in fish and surface water is part of the agency’s National Rivers and Stream Assessment, she added.
The current study was funded by a $150,000 EPA grant.
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