Steroids given to livestock can stay in the water for a long time and don't always break-down, a new study has found. Researchers said that regulatory agencies might have to closely monitor some "safe" livestock steroids to prevent damage to the aquatic ecosystem.
Anabolic steroids are usually given to livestock to boost their growth and are generally believed to be harmless. But, researchers at the University of Nevada, Reno and colleagues found that certain steroids such as trenbolone might not breakdown completely as previously thought.
"Our team found that these substances, after a rapid breakdown in sunlight, are capable of a unique transformation in aquatic environments under various temperature and light-cycle scenarios where the process is reversed," said Ed Kolodziej, co-author of the paper and environmental engineering associate professor at the University of Nevada, Reno.
According to Kolodziej and his team, the study findings might also help understand why certain fishes and other marine organisms have now started showing changes in reproductive cycles. Trenbolone works by binding with androgen, hormones that increase muscle build-up. The steroids works more efficiently than testosterone and is even used by male athletes to increase muscle mass. The steroid is banned for use in humans in many countries, including the United States. Even in small doses, the steroid could disrupt the reproductive cycle in women and can lead to virilization.
The present research was based on both lab and field studies. The scientists found that the steroid broke down in the presence of sunlight, but never fully disappeared. The study even found that under surface water conditions, the steroid persisted. Interestingly, the remains of the steroid got together at night and regenerated the initial steroid.
"We knew something unique was going on," David Cwiertny, Kolodziej's research partner from the University of Iowa, said in a news release. "In daylight, it essentially hides in another form, to evade analysis and detection, and then at nighttime it readily transforms back to a state that we can detect."
"Right now, I'm not alarmed, just concerned and interested in defining the real ecological risks associated with the widespread use of potent steroidal pharmaceuticals," Kolodziej added. He has been studying the effects of these substances on aquatic ecosystems for 12 years.
The study is published in the journal Science.