Pharmaceutical Pollution Wreaks Havoc on Nation's Rivers

Pharmaceutical pollution is now being detected in bodies of water throughout the nation and its effects are debilitating for local plant and animal life, according to a paper published in Ecological Applications.

Lead author Emma Rosi-Marhsall is a scientist at the Cary Institute of Ecosystem Studies and the study's lead author. The reasons for the pollution, Phys.org reports her as having said, are widespread.

"Causes include aging infrastructure, sewage overflows, and agricultural runoff," she explained. "Even when waste water makes it to sewage treatment facilities, they aren't equipped to remove pharmaceuticals. As a result, our streams and rivers are exposed to a cocktail of synthetic compounds, from stimulants and antibiotics to analgesics and antihistamines."

Along with her colleagues from Indiana University and Loyola University Chicago, Rosi-Marshall looked at how six widely-used pharmaceuticals impacted streams of similar sizes in New York, Maryland and Indiana.

Included were Caffeine, the antibiotic ciprofloxacin, the antidiabetic netformin, two antihistimines used to treat heartburn and another used to treat allergies.

The group focused on the slippery coating on the rocks in the streams, known as biofilm, because, Rosi-Marshall explained, "they're vital to stream health."

"They may not look like much to the naked eye," she admits, "but biofilms are complex communities composed of algae, fungi, and bacteria all living and working together."

Because of this, if a stream is healthy, its rocks are slippery - and vice versa.

As it turns out, the antihistimine diphenhydramine - used in treating allergic symptoms as well as motion sickness, insomnia and a cold - decreased a biofilm's photosynthesis by 99 percent in addition to drops in respiration. And it didn't stop there. The chemical compound actually caused a change in present bacterial species, including a reduction of a group that digests compounds produced by plants and algae.

Nor was it the only one tested to render similar results; in fact, all the pharmaceuticals involved in the study had a measurable and negative impact on biofilm respiration.

Rosi-Marshall warned that such effects could be wide-sweeping.

"We know that diphenhydramine is commonly found in the environment," she said. "And its effect on biofilms could have repercussions for animals in the environment. And its effects on biofilms could have repercussions for animals in stream food webs, like insects and fish."