Leaky sewers are likely responsible for large amounts of medications in streams

Date:
August 18, 2021
Source:
American Chemical Society
Summary:
Pharmaceutical compounds can harm the environment. However, in
waterways that don't receive treated wastewater, these pollutants
aren't expected to be present. Now, researchers have found that
amounts of some medications carried by a stream in Baltimore were
substantial, despite generally low concentrations over the course
of a year. Because wastewater plants don't impact this stream,
the high loads are likely coming from leaking sewer pipes, they say.



FULL STORY ========================================================================== Pharmaceutical compounds can harm the environment. However, in waterways
that don't receive treated wastewater, these pollutants aren't expected
to be present. Now, researchers reporting in ACS' Environmental Science & Technology have found that amounts of some medications carried by a stream
in Baltimore were substantial, despite generally low concentrations over
the course of a year. Because wastewater plants don't impact this stream,
the high loads are likely coming from leaking sewer pipes, they say.


========================================================================== Thousands of medications are approved for human use in the U.S., and
many of them are harmful to microorganisms, algae and insects when
they make their way into lakes and streams through wastewater. The concentrations of pharmaceutical compounds are usually used to determine
their impact on organisms living in streams and rivers. However,
contaminant concentrations may change quickly from one day to the next,
and so singular snapshots do not correctly illustrate their cumulative
effects on aquatic life. Instead, load -- the mass of a pollutant that
passes through a 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 considered for pharmaceuticals. So, Megan Fork
and colleagues wanted to get an idea of the yearly load of medicines transported by an urban stream in Baltimore.

The researchers tested water from an urban stream draining into
Baltimore's Inner Harbor in Maryland on a weekly basis for a year. At
the outflow point, they found 16 pharmaceutical compounds whose
presence and amount varied considerably from week to week, ranging from concentrations of parts per trillion to parts per billion. Trimethoprim
-- an antibiotic -- was found most regularly, but acetaminophen -- a
common pain reliever -- was at the highest concentrations. The team used
their weekly measurements to estimate annual loads of pharmaceuticals, calculating that the equivalent of 30,000 doses of antidepressants,
1,700 doses of antibiotics and 30,000 tablets of acetaminophen entered
the Inner Harbor through the stream. Interestingly, this watershed did
not receive wastewater treatment plant effluent, so it's likely these
compounds are coming from leaky sewer pipes. Improvements to aging infrastructure could reduce this source of harmful compounds to urban
streams and other waterways, the researchers say.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Megan L. Fork, Jerker B. Fick, Alexander J. Reisinger, Emma J. Rosi.

Dosing the Coast: Leaking Sewage Infrastructure Delivers Large
Annual Doses and Dynamic Mixtures of Pharmaceuticals to Urban
Rivers.

Environmental Science & Technology, 2021; DOI:
10.1021/acs.est.1c00379 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/08/210818084007.htm

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