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Emily E Woodward

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Neonicotinoids have become the most widely used insecticides in world with rapid growth in applications as seed coatings. Nontarget organisms are exposed to concentrated levels of pesticidal active ingredients through ingestion of treated seeds. To better understand pesticide fate, analytical methods are necessary to rapidly screen and accurately quantitate contaminants in environmental and biological matrices. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is commonly employed for neonicotinoid analyses but requires expensive analytical instrumentation and potentially laborious sample preparation. Enzyme-linked immunosorbent assays (ELISAs) are efficient and sensitive alternative methods for neonicotinoid...
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One phenomenon that has been shown to concentrate and release per- and polyfluoroalkyl substances (PFAS) in surface water is the formation of natural foams. For surface water foams to form, surface active compounds or surfactants must be present in the water along with a source of gas bubbles. Some examples of surface-active compounds include humic and fulvic acids, colloidal particles, and lipids and proteins. The relationship between PFAS and dissolved organic matter (DOM) is important because studies have shown that DOM can affect PFAS fate and bioavailability in aquatic systems and treatment processes. The results from this assessment will improve our understanding of PFAS fate and transport in the environment....
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Irrigation runoff and soil samples were collected from a lettuce field located at the USDA-ARS Spence Research farm in the Salinas Valley, California to measure neonicotinoid insecticides (clothianidin and imidacloprid) and a fungicide (azoxystrobin) applied via coated seed and drench treatments. The field trial was designed to evaluate four treatments with replication: 1) control, untreated seed, 2) imidacloprid treated seed, 3) clothianidin treated seed, and 4) azoxystrobin treated seed with an imidacloprid drench. Samples were collected from each treatment over two lettuce growing seasons: August to October 2019 and September to October 2020. Runoff samples were collected over both growing seasons during 6 irrigation...
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Here we report optical data collected as part of a collaborative study between USGS Pennsylvania Water Science Center, Pennsylvania Department of Environmental Protection and Water Mission Area Proxies Project. The optical measurements reported here were collected to aide in the characterization of water sources and mixtures and establish proxies (surrogates) for per- and poly-fluorinated alkyl substances within the Neshaminy Creek basin. Data are compiled into three tables: 1) full fluorescence spectra in vectorized format, 2) full absorbance spectra, and 3) summary file of commonly extracted optical indicators and field-based sensor arrays.
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Nitrapyrin, 6-CPA, and herbicide concentrations in agricultural soils, subsurface drains, and corresponding streams in the Midwestern US
Nitrapyrin is a nitrification inhibitor that is co-applied with N-fertilizer in agroecosystems. Over the course of one year (March 2016 to June 2017), 192 water samples from seven streams across Iowa and Illinois were analyzed for nitrapyrin, its degradate 6-chloropicolinic acid (6-CPA), and three widely used herbicides acetochlor, atrazine, and metolachlor. Additional environmental samples were collected and analyzed in spring 2017: 63 water samples from eight subsurface drains, and 33 soil samples from a field in Iowa that received direct application of nitrapyrin (only for nitrapyrin and herbicides). Nitrapyrin was detected in all seven streams (56% detection) with concentrations ranging from 4 to 1,200 ng/L;...
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