Persistence of pharmaceuticals in effluent-dominated surface waters.

Pharmaceutical fate in surface water depends on a combination of physical and chemical processes, but currently, little information is available on cumulative dissipation rates in effluent-dominated receiving waters. In this study, dissipation rates were calculated for pharmaceutical compounds in two streams receiving municipal wastewater effluents using results from passive samplers. Seventeen pharmaceuticals were detected at the two sampling locations, and first-order dissipation rates were found to range between 0.03 and -0.02 h, indicating that some compounds were conserved, while others rapidly dissipated over several kilometers downstream of the source.