Just when you thought it was safe to go back into the water.
We all know that endocrine disruptors like those found in disposable water bottles are bad news, which is why we’ve been changing the way we use containers and other products in our lives. Until recently, though, researchers thought that these chemicals broke down naturally and eventually became inert. That’s why a new discovery is causing such alarm: apparently, endocrine disruptors are capable of reassembling themselves, returning “from the dead like zombies” to cause continuing health problems.
These chemicals can come from steroids and other drugs given to cattle, human medications that end up in the water supply, additives put in plastic products, and a variety of industrial sources. While theoretical pollution controls should keep them out of the water supply in the first place, carelessness and accidents happen, leading to the distribution of hormone disruptors through lakes, rivers and streams. That’s bad for fish, plants and other organisms relying on that water to survive.
Scientists knew that was bad enough, but they believed hormone disruptors broke down in exposure to sunlight. Thus, with every UV cycle, more of the chemicals would be broken down into components that wouldn’t be harmful; nature’s way of addressing the problem, as it were. However, researcher Edward Kolodziej took these chemicals into a lab to see if this was actually the case. He and his team took 17α-trenbolone into their lab and monitored levels through dark and light cycles.
What they found was disturbing. In the light, the chemical broke down, with levels declining. But at night, the level built back up. This explained why testing results could show low levels of endocrine disruptors in a waterway, but animals relying on the water could still show signs of illness and health problems related to excessively high exposure. Depending on when water samples were drawn, scientists would naturally have received radically different readings on chemical concentration, and thus might have drawn false conclusions.
Finally, we have an explanation for why fish and other animals can show signs of hormone disruption even when the concentration of harmful chemicals in their water appears low: because in reality, it isn’t. Every night, these chemicals reform, damaging organisms living in the water and then breaking down again the next day, right in time for a researcher to dip a sampling tube into the water to check on its quality.
Solving a frustrating mystery is great news, but the solution to the mystery is grim. This information indicates that the situation with pollution in lakes and streams is an even bigger problem than previously believed, and that new methods are necessary to tackle the issue. It’s not enough for chemicals to break down once if they’ll just be back the next night, and that makes it even more critical to control them at their source. Without that, their levels will keep building up in our waterways, causing a growing number of health problems for aquatic animals and plants.
Photo credit: epSos.de.