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David A Alvarez

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This dataset includes pesticides and pesticide transformation products in 15 tributaries of the Great Lakes. Pesticides were monitored using polar organic chemical integrative samplers (POCIS) to estimate concentrations in water following standard protocols (Alvarez, 2010) in June and July 2016. POCIS extracts were analyzed for 225 chemicals (USGS National Water Quality Laboratory schedule 5437, Sandstrom and others, 2016), for which 129 chemicals also have POCIS uptake rates, allowing calculations of time-weighted mean concentration over the approximately 30 day deployment (Alvarez and others, 2008). Collectively, there were 97 chemicals detected, and time-weighted mean concentrations could be calculated for 95...
Two types of passive samplers for polychlorinated biphenyl (PCB) analysis were deployed in the Clinton River Area of Concern in 2019: semipermeable membrane devices for water and in-stream sediment samplers. Samplers were deployed in July 2019 and retrieved in August 2019. Additionally, bank sediment samples for PCB analysis were collected by the U.S. Geological Survey (USGS) in August 2019 and catch basin bottom material samples for PCB analysis were collected by LimnoTech in November 2019 under contract with the U.S. Army Corps of Engineers. These data are a part of a larger study and associated USGS report (https://doi.org/TBD).
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In 2013, the U.S. Geological Survey and the U.S. Environmental Protection Agency characterized water-quality stressors and ecological conditions in 100 wadeable streams across the Midwestern United States. The goal of the study was to determine the relative effects of multiple ecological stressors – contaminants, nutrients, sediment, and habitat – on ecological communities in the streams. The Midwest is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers...
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