It turns out the medicine and personal care products we use may be having some quite detrimental effects in our sewage treatment plants, streams, rivers, lakes, bays and the ocean.
Testing sludge bacteria
Rutgers scientists tested the ability of bacteria in sludge from a sewage treatment plant to break down pharmaceutical products and compounds in personal care products.
What they found was that the bacteria only broke down one of the compounds completely. The three other chemicals were only partially broken down and even worse the bacteria created new contaminants in the breakdown process.
"The partial breakdown of pharmaceuticals and personal care products is important because it results in a stream of possible contaminants in waterways that may have biological effects on impacted environments," said Abigail W. Porter, corresponding author and teaching instructor in the Department of Environmental Sciences at Rutgers University-New Brunswick. "These contaminants and their potential risks have yet to be studied."
These contaminants are increasingly found at low levels in surface water, according to the U.S. Environmental Protection Agency. This has led to growing concerns that the contaminants may soon affect aquatic life and even impact human health.
"Our findings can help us assess other widely used pharmaceutical and personal care products with similar chemical structures," said co-author Lily Young, Distinguished Professor in the Department of Environmental Sciences. "By predicting or assessing the chemicals that might form during the breakdown process, we can identify and quantify them in the environment."
Two bacterial communities
For this study, the Rutgers scientists looked at how anaerobic microorganisms break down the chemicals in pharmaceuticals and personal care products. The researchers explored two bacterial communities.
One was in sludge from a sewage treatment plant and the other in a clean marine environment off Tuckerton, New Jersey. They looked at the way these bacteria transformed four components: naproxen, an anti-inflammatory drug, guaifenesin, an expectorant, oxybenzone, a key ingredient in sunscreens, and methylparaben, a preservative.
The first two were found in medicine and the other two in personal care products. What they found was that both types of bacteria could transform the anti-inflammatory drug naproxen. However, both also struggled to transform the other three chemicals and worse created further contaminants during the breakdown process.
The study is published in the journal Environmental Toxicology and Chemistry.