Metformin and Other Pharmaceuticals Widespread in Wadeable Streams of the Southeastern United States

Pharmaceutical contaminants are growing
aquatic-health concerns
and largely attributed to wastewater treatment facility (WWTF) discharges.
Five biweekly water samples from 59 small Piedmont (United States)
streams were analyzed for 108 pharmaceuticals and degradates using
high-performance liquid chromatography and tandem mass spectrometry.
The antidiabetic metformin was detected in 89% of samples and at 97%
of sites. At least one pharmaceutical was detected at every site (median
of 6, maximum of 45), and several were detected at ≥10% of
sites at concentrations reported to affect multiple aquatic end points.
Maximal cumulative (all detected compounds) concentrations per site
ranged from 17 to 16000 ng L–1. Watershed urbanization,
water table depth, soil thickness, and WWTF metrics correlated significantly
with in-stream pharmaceutical contamination. Comparable pharmaceutical
concentrations and detections at sites with and without permitted
wastewater discharges demonstrate the importance of non-WWTF sources
and the need for broad-scale mitigation. The results highlight a fundamental
biochemical link between global human-health crises like diabetes
and aquatic ecosystem health.