A new study claims that leaking pipes from Baltimore’s aging infrastructure is polluting the Chesapeake Bay with thousands of human doses of pharmaceuticals per year. Study lead author Megan Fork is a postdoctoral research associate at Cary Institute of Ecosystem Studies.
“Pharmaceuticals enter freshwaters through multiple pathways, including effluent from wastewater treatment and septic systems, as well as agricultural runoff,” said Fork. “An important, but often overlooked contributor is aging and faulty wastewater infrastructure, which is common in many older cities.”
To understand the amount of pharmaceuticals entering the environment from leaking pipes alone, the scientists chose to research the Gwynns Falls watershed, a location where no wastewater is discharged. The researchers monitored six sites in the watershed, taking samples every week for a year and screening for 92 pharmaceutical compounds.
Across all of the sites, 37 compounds were found. Pain relievers and antibiotics were commonly detected in the water samples. “Establishing the loads of contaminants such as pharmaceuticals is important since low concentrations may mislead regulators and managers into thinking that they are insignificant,” explained Fork.
“In Baltimore we are already seeing that stream-dwelling bacteria are resistant to common antibiotics, suggesting that low chronic exposures can result in significant effects on stream life.”
Study senior co-author Emma Rosi noted that this study can be scaled up to look at an entire region.
“We estimate that nearly 1 percent of raw sewage originating in the Gwynns Falls watershed flows into the environment via leaking infrastructure. If we extrapolate our calculations to the entire Chesapeake Bay watershed, we estimate that approximately 11.7 billion liters of raw sewage may enter the Bay via leaks every year – carrying a range of pharmaceutical compounds that can affect aquatic organisms and disrupt ecosystem processes,” said Rosi.
The scientists point out that the research is important because it highlights the threat of uncommon “pollution pathways” rather than just the usual suspects. We must look at everything if we are aiming to maintain healthy environments.
The study is published in the journal Environmental Science & Technology