Could Your Medicine and Personal Care Products be Polluting Waterways?

By Duru Cosar

Scientists from Rutgers University have determined that bacteria in sewage treatment plants could be making new contaminants that have not been tested for personal risks, and they may be harming the aquatic environments. The scientists tested how well the bacteria from the sewage treatment plants could break down two common pharmaceutical products, naproxen and guaifenesin. Naproxen is a non-steroidal anti-inflammatory drug and guaifenesin is an expectorant in many cough and cold medicines. They also looked at two common compounds from personal care products, oxybenzone which is found in sunscreen, and methylparaben, a preservative in cosmetics. They found that bacteria that don’t require oxygen to grow in the sewer sludge broke down methylparaben, but they only broke down the three other chemicals partially, creating new contaminants in the process. Abigail W. Porter, an author and teaching instructor in the Department of Environmental sciences at Rutgers University-New Brunswick, claims that the partial breakdown of pharmaceuticals and personal care products is important because it leads to contaminants clogging up the water ways and affecting certain environments.

The scientists also looked at how bacteria that thrive in conditions with no oxygen can break down the chemicals found in pharmaceuticals and personal care products. They studied a sludge bacterial community from a sewage treatment plant and the other in a low oxygen subsurface sediment from a clean environment in Tuckerton, New Jersey. They determined that the communities had different kinds of bacteria, but both communities were able to transform the four chemicals in the same way. In the future, the researchers hope to look at sediment samples from different locations to study the long-term persistence of transformed chemicals.


Rutgers University. "Medicine and personal care products may lead to new pollutants in waterways: Bacteria in wastewater plants transform widely used chemicals." ScienceDaily. ScienceDaily, 21 March 2019. <>.