Human pharmaceuticals, hormones, and personal care product ingredients in runoff from agricultural fields irrigated with treated wastewater

Irrigation of crops with treated wastewater has the potential to introduce effluent-derived organic microcontaminants into surface waters through agricultural runoff. To determine whether compounds indicative of the presence of treated effluent in irrigation water could be identified in agricultural runoff, surface runoff samples collected from effluent-irrigated and rain-fed cultivated fields were analyzed for a broad spectrum of organic compounds. A variety of compounds was identified that appeared to be associated with irrigation with treated wastewater. These compounds included human pharmaceuticals (e.g., carbamazepine, gemfibrozil, carisoprodol), personal care product ingredients (e.g., insect repellent, polycyclic musks), and alkyl phosphate flame retardant chemicals. Most of these compounds appear not to have been previously reported in agricultural runoff. These compounds were present at concentrations below the few published aquatic toxicology data available; however, their potential to elicit more subtle effects in aquatic organisms cannot be excluded. None of these compounds were detected by broad-spectrum analysis in samples from the same fields during runoff-producing rain events.