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Pharmaceuticals in Surface Waters and Potential Transfer to Irrigated Food Crops
Citation:
Sanchez, C. A. AND T. L. JONES-LEPP. Pharmaceuticals in Surface Waters and Potential Transfer to Irrigated Food Crops. Presented at Second International Conference on Occurrence, Fate, Effects, and Analysis of Emerging Contaminants in the Environment, Ft. Collins, CO, August 04 - 07, 2009.
Impact/Purpose:
Presentation
Description:
A number of pharmaceuticals have been detected in surface waters across the United States. The objective of this study was to evaluate the presence of selected pharmaceuticals (macrolidic antibiotics and pseudoephedrine) and illicit drugs (methamphetamine, Ecstasy) in surface waters in the southwestern U.S. and evaluate the potential for food chain trans fer when pharmaceutical containing waters are used for irrigation. Samples were collected spatially and temporally from waste stream tributaries and receiving surface waters in the southwestern US. Studies included greenhouse experiments, where selected food crops were irrigated with water spiked with macrolide antibiotics and field experiments, where selected field crops were irrigated with treated waste water effluent containing one or more macrolide antibiotics, pseudoephedrine, and methamphetamine. Water samples were prepared for analysis using an automated extractor (AutoTrace, Caliper Life Sciences) with Oasis MCX cartridges (Waters Corp.), subsequently extracted with 5-mL of 80:20:1 methyl tertbutyl ether/methanol/acetic acid, and 5 mL 99:1 methanol/acetic acid, and reduced to 0.5 mL using an automated evaporator (TurboVap-Zymark, Caliper Life Sciences). Plant materials were extracted using a modified pressurized liquid extraction (PLE) technique, followed by a rigorous hexane clean-up. Water extracts and plant PLE extracts were analyzed by liquid chromatography-electrospray-ion trap mass spectrometry (LC-ESI-ITMS/MS) in the positive ionization collision induced mode (CID) for greater specificity. One or more of the pharmaceuticals and/or illicit drugs evaluated were found in urban waste streams at concentrations sometimes exceeding 500 ng/L. However, amounts found in the main surface water channels were always below 10 ng/L and most frequently below detection. The results of the greenhouse and field studies indicate the uptake of one or more of the pharmaceuticals evaluated, albeit at very low- levels, into several of the crops species.