Environmental pollution by pharmaceuticals is increasingly recognized as a major threat to aquatic ecosystems worldwide. A variety of pharmaceuticals enter waterways by way of treated wastewater effluents and remain biochemically active in aquatic systems. Several ecotoxicological studies have been done, but generally, little is known about the ecological effects of pharmaceuticals. Here we show that a benzodiazepine anxiolytic drug (oxazepam) alters behavior and feeding rate of wild European perch (Perca fluviatilis) at concentrations encountered in effluent-influenced surface waters. Individ

...I can't help but wonder how much of this "medical residue" finds its way back into drinking water, and what potential effects it may have on humans.

The conventional water treatment plants cannot remove prescription drugs in drinking water supply (See Figure 1). Disinfection with the used of Chlorine is one of the steps in treating raw water. However, chlorination makes most of the prescription drugs more hazardous and it can produce cancer inducing chemical compounds or carcinogens during the treatment procedure as illustrated on Figure 1.