Cattle Growth Steroids May Impact Water Supply, Aquatic Life: Study

An anabolic steroid once thought to completely breakdown in sunlight is now believed to regenerate at night, and may pose a threat to aquatic life and water supplies, according to a new study. 

Trenbolone acetate is an anabolic steroid often given to cattle to increase weight gain and promote feeding efficiency. While it has been widely thought that it poses no threat to the environment or to humans after being broken down, a study published last week in the journal Science raises serious questions about the safety of the cattle growth steroid.

Researchers from the University of Iowa and the University of Nevada, Reno, have found that trenbolone does not degrade completely. A small portion of the chemical’s structure remains and can be regenerated at night under optimal conditions, prompting scientists to dub trenbolone the ‘vampire steroid.’

The process occurs after cattle is fed trenbolone. The cattle excrete the steroid in their feces which is broken down, entering the environment through waterways and water runoff.

Typically, trenbolone breaks down through photo-transformation, or exposure to sunlight. However, under certain conditions the steroid retains enough of its chemical residue to regenerate.

When surface waters reach 25 degrees Celsius and have a pH level of 7, trenbolone can regenerate in the water after the sun sets.

This same phenomena was also observed in two other chemicals. Dienedone, another anabolic steroid, and lenogest, a hormone used in the Natazia birth control pill.

Both dienedone and trenbolone are banned from use in humans because of endocrine disruption. Once popular among bodybuilders and weightlifters, the chemical is now a schedule III controlled substance but was approved by the FDA for use in cattle.

David Cwierny, co-author of the paper and Assistant Professor of Engineering at the University of Iowa, and his team of researchers are concerned about the implications of their findings. With trenbolone metabolites readily available to reenter the environment, the steroid is also readily available to affect aquatic life.

Because Trenbolone easily enters the environment through cattle excretion, it becomes a major threat to water safety near agricultural sites. Researchers say there will be little direct effect on humans, however a major impact to aquatic life may result, considering more than 20 million cattle have been implanted with trenbolone steroids in the U.S.

Researchers say the results of this study call for further research on the effects of photo-transformation of certain chemicals. Many of these chemicals, like trenbolone, were only tested during daytime situations. Further nighttime testing should be conducted to determine the effects of the drug on surface waters and its larger role in effecting the environment.

“There are a variety of bioactive pharmaceuticals and personal-care products that we know are present in trace amounts in our water supply,” said Cwierny. “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.”

Photo Courtesy of Steve A Johnson via Flickr CC 2.0