A new study published in the journal Ecosphere confirms that in urban streams, persistent pharmaceutical pollution can cause aquatic microbial communities to become resistant to drugs. Researchers evaluated the presence of pharmaceuticals, including painkillers, stimulants, antihistamines and antibiotics, in four streams in Baltimore, Maryland. Then they measured the microbial response to drug exposure. Selected study sites represented a gradient of development from suburban to urban.

Emma Rosi, an aquatic ecologist at the Cary Institute of Ecosystem Studies and lead author on the study, explains, “Wastewater treatment facilities are not equipped to remove many pharmaceutical compounds. We were interested in how stream microorganisms, which perform key ecosystem services like removing nutrients and breaking down leaf litter, respond to pharmaceutical pollution. When we expose streams to pharmaceutical pollution, we are unwittingly altering their microbial communities, yet little is known about what this means for ecological function and water quality.”

This article appears in the May 2018 issue of Natural Awakenings.