Antibiotics in wastewater is a problem, one that scientists have known about for years. But according to a recent study by Olya Keen, assistant professor of civil and environmental engineering at UNC Charlotte, attempts to break down organic matter in wastewater is actually making those antibiotics stronger.
Chlorine is often added to wastewater in order to remove potentially dangerous organic matter within it. The chlorine is filtered out before that water is allowed to pass through to later stages. Unfortunately, chlorine isn’t able to destroy antibiotics, which pass through without a problem and can end up in streams and other water sources. Once there, these antibiotics interact with bacteria in those water sources, which can eventually develop immunity to those antibiotics.
Keen and her students isolated doxycycline, which is one of the more commonly used classes of antibiotic, for the study. They found that not only does chlorine not kill the antibiotic, it actually makes it stronger by changing its chemical makeup and creating new antibiotics.
As more antibiotics get out into the wild, bacteria will have the time and the room to adapt to them and become immune, resulting in bacteria that humans and other animals cannot fight off. This doesn’t normally happen with patients taking antibiotics, as the bacteria don’t have time to create enough generations to adapt and end up dying off.
The antibiotics in wastewater get there in a variety of ways. Any not broken down in the human body can end up being released through bodily waste, but many individuals and even hospitals dump old or expired antibiotics down the toilet, which is part of the problem. Runoff from factories and labs producing antibiotics contributes to the problem as well.
Keen’s research will give us more insight into the problem, and she hopes that it will lead to better solutions for removing antibiotics from wastewater or preventing them from entering it in the first place.