Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers

摘要: The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability pesticide concentrations makes characterization of their exposure organisms challenging. To compensate for the effects variability, we deployed polar organic chemical integrative samplers (POCIS) 100 small across about 5 weeks during summer 2013 and analyzed extracts 227 compounds. Analysis water samples collected weekly POCIS deployment allowed comparison results with periodic water-sampling results. median number detected was 62, 141 compounds were at least once, indicating a high level contamination region. Sixty-five degradates. Mean estimated using published sampling rates strongly correlated means concurrently, however, POCIS-estimated generally lower than measured concentrations. Summed herbicide (units ng/POCIS) greater sites urban summed insecticides fungicides sites. Consistent these differences, herbicides correlate percent cultivated crops watersheds land use. With exception malathion nine sites, aquatic-life benchmarks. provide alternative approach traditional characterizing chronic