From the ACS Press Room
Leaky Sewers are Likely Responsible for Large Amounts of Medications in Streams “Dosing the Coast: Leaking Sewage Infrastructure Delivers Large Annual Doses and Dynamic Mixtures of Pharmaceuticals to Urban Rivers”
stream or river over time — better represents the risks to downstream environments, where the contaminants end up. While loads are used in regulations for traditional pollutants, such as nutrients, they have not been considEnvironmental Science & Technology ered for pharmaceuticals. So, Megan Fork Pharmaceutical compounds can harm the en- and colleagues wanted to get an idea of the vironment. However, in waterways that don’t yearly load of medicines transported by an receive treated wastewater, these pollutants urban stream in Baltimore. aren’t expected to be present. Now, researchers reporting in ACS’ Environmental Sci- The researchers tested water from an urban ence & Technology have found that amounts stream draining into Baltimore’s Inner Harof some medications carried by a stream in bor in Maryland on a weekly basis for a year. Baltimore were substantial, despite generally At the outflow point, they found 16 pharmalow concentrations over the course of a year. ceutical compounds whose presence and Because wastewater plants don’t impact this amount varied considerably from week to stream, the high loads are likely coming from week, ranging from concentrations of parts per trillion to parts per billion. Trimethoprim leaking sewer pipes, they say. — an antibiotic — was found most regularly, Thousands but acetaminophen — a common pain relievof medica- er — was at the highest concentrations. The tions are team used their weekly measurements to estiapproved mate annual loads of pharmaceuticals, calcufor human lating that the equivalent of 30,000 doses of use in the antidepressants, 1,700 doses of antibiotics U.S., and and 30,000 tablets of acetaminophen entered many of them are harmful to microorgan- the Inner Harbor through the stream. Interestisms, algae and insects when they make their ingly, this watershed did not receive way into lakes and streams through wastewater treatment plant effluent, so it’s wastewater. The concentrations of pharma- likely these compounds are coming from ceutical compounds are usually used to deter- leaky sewer pipes. Improvements to aging mine their impact on organisms living in infrastructure could reduce this source of streams and rivers. However, contaminant harmful compounds to urban streams and concentrations may change quickly from one other waterways, the researchers say. day to the next, and so singular snapshots do not correctly illustrate their cumulative ef- The authors acknowledge funding from the fects on aquatic life. Instead, load — the U.S. National Science Foundation. mass of a pollutant that passes through a Septemeber 2021
The Southwest RETORT
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