Assessing the risk posed to aquatic organisms by the discharge of certain steroids and pharmaceutical products into waterways is often based on a belief that as the compounds degrade, the ecological risks naturally decline.
But there's growing sentiment that once in the environment, some of these bioactive organic compounds may transform in a way that makes their presumed impact less certain.
A new study led by the University of Iowa and published online Thursday in the journal Science found this was the case with the anabolic steroid trenbolone acetate and two other drugs.
Once popular in the bodybuilding and weightlifting communities,trenbolone acetate is now banned for human use. However, it is federally approved for use by the beef industry to promote weight gain and increase feeding efficiency in cattle.
In lab tests followed by field experiments, the researchers found that trenbolone does not fully break down in water as believed, retaining enough of a chemical residue to regenerate itself in the environment under certain conditions, to an extent that the drugs' lives may be prolonged, even in trace amounts.
Researchers says the study is a first step toward better understanding the environmental role and impact of steroids and pharmaceutical products, all of which have been approved by the federal government for various uses and that have been shown to improve food availability, environmental sustainability and human health.
"We're finding a chemical that is broadly utilized, to behave in a way that is different from all our existing regulatory and risk-assessment paradigms," says David Cwiertny, assistant professor in engineering at the University of Iowa and a co-corresponding author on the paper."What our work hopefully will do is help us better understand and assess the environmental fate of emerging contaminant classes. There are a variety of bioactive pharmaceuticals and personal-care prod
|Contact: Richard Lewis|
University of Iowa