FDA approved steroids used to boost growth in cattle remain in the environment especially in water bodies longer than expected. This increases the level of chemicals in rivers and streams, in turn affecting its aquatic life.

Certain steroids like trenbolone have been approved by the U.S. Food and Drugs Administration and are fed to livestock to boost their growth. Trenbolone steroids are still banned for human use and are also known to damage reproductive organs of marine life. However, the drug is believed to degrade rapidly when discharged into waterways, thus decreasing the threat they may pose to the environment.

Now researchers of a new study found that this may not be entirely true. The scientists from the University of Iowa found that the drug remains in the environment for longer than previously believed. They found that at night, when the sun goes down and the pH level of water bodies is correct, the molecules of trenbolone reassemble. This means the amount of the chemical in water sources, which has likely been sampled and tested during the day, may actually be higher than previously believed.

"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," study corresponding author David Cwiertny, an assistant professor in engineering at the University of Iowa, said in a news release.

"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 products that we know are present in trace amounts in our water supply. We should use what we're learning about trenbolone to more closely scrutinize the fate and better mitigate the impact of these products in the environment," he explained.

Researchers made similar observations when they tested dienogest and dienedone. Dienogest is a hormone used in Natazia, a birth control pill and Dienedone is a banned anabolic steroid that had been sold as a body-building supplement.

Over 20 million cattle in the United States have trenbolone implanted in their ears. The drug is  finally excreted by the cattle.  If consumed by humans, it may cause many health problems.

The authors of the study have called on drug manufacturers to come up with more eco-friendly steroids for cattle, which are not only environment-friendly but also decompose easily, posing less of a threat to both humans and other species.