2013 Annual Report
Studies investigating chlorine dioxide-related residues on vegetable matter during fumigation were conducted. Effects of gas concentration and exposure to light on chlor-oxyanion levels in rinse fractions and in edible tissues were measured. Chlorate levels were measured in blood, drinking water, and uterine fluid of sheep that had been dosed with single or multiple doses of sodium chlorate. Analytical methods included ion chromatography and LC-MS/MS.
Objective 2. The fate and transport of ractopamine HCl were determined in two soil types using sterile and non-sterile conditions. Soils employed were of relevance to agronomic practices in the Midwest region of North America. Both the sorption and degradation of ractopamine HCl and were measured. Greenhouse studies were also conducted to determine the uptake of ractopamine HCl by alfalfa and wheat from Midwestern soils. The presence of ractopamine in edible plant parts was measured subsequent to plant maturation.
The fate of estradiol-sulfate (E2S) in a soil-water system was studied in sterile and non-sterile soil, and with soils of high and low organic content. The contribution of each soil variable to E2S degradation, sorption, and transport in water was measured.
Background estrogens in ground and surface water samples from sites not impacted by agricultural practices for over a decade have been measured. Additionally, water samples from fields receiving their first application of estrogen-laden manures are being analyzed.
Estrogenic activity in serum from a number of food-animal species including sheep, cattle, swine, and catfish was measured using an in vitro E-screen bioassay. The bioassay was tested for its ability to detect estrogenic activity under normal physiologic conditions and when animals were exposed to natural and man-made dietary estrogens. Estrogenic activity in serum from mares exposed to a fungal estrogen was also evaluated.
In an interagency collaboration, the estrogenic activity in 19 streams distributed across 12 US states was surveyed. The streams were in proximity to dairy, grazing, or feedlot cattle; swine, or poultry operations; and 4 areas without livestock (or livestock manure application). Estrogenic activities of all watersheds were consistently below the United Kingdom's proposed Lowest Observable Effect Concentration for estradiol in fish (10 ng/L), regardless of land use.
Objective 3. Analytical methods based on UPLC-MS or UPLC-MS/MS were developed and/or improved for the detection of chlorate salts in a number of food matrices including vegetables and melons. The methods have been used to support efforts to investigate the fate of chlorate in food animals and to investigate the formation of chloroxyanion byproducts after chlorine dioxide fumigation of vegetables and melons.
Shrestha, S.L., Casey, F.X.M., Hakk, H., Padmanabham, G. 2013. A radioassay-based approach to investigate fate and transformation of conjugated and free estrogens in an agricultural soil. Environmental Engineering Science. 30:89-96.
Smith, D.J., Anderson, R.C. 2013. Toxicity and metabolism of nitroalkanes and substituted nitroalkanes. Journal of Agricultural and Food Chemistry. 61:763-779.
Shelver, W.L., Tell, L.A., Wagner, S., Wetzlich, S.E., Baynes, R.E., Riviere, J.E., Smith, D.J. 2013. Comparison of ELISA and LC-MS/MS for the measurement of flunixin plasma concentrations in beef cattle after intravenous and subcutaneous administration. Journal of Agricultural and Food Chemistry. 61:2679-2686.
Shappell, N.W. 2013. Egg wash wastewater: Estrogenic risk or environmental asset? Integrated Environmental Assessment and Management. 9(3):517-523.
Alvarez, D.A., Shappell, N.W., Billey, L.O., Bermudez, D.S., Wilson, V.S., Kolpin, D.W., Perkins, S.D., Evans, N., Foreman, W.T., Gray, J.L., Shipitalo, M.J., Meyer, M.T. 2013. Bioassay of estrogenicity and chemical analysis of estrogens in streams across the United States associated with livestock operations. Water Research. 47:3347-3363.
Xu, T., Xu, Q.G., Li, H., Wang, J., Li, Q.X., Shelver, W.L., Li, J. 2012. Strip-based immunoassay for the simultaneous detection of the neonicotinoid insecticides imidacloprid and thiamethoxam in agricultural products. Talanta. 101:85-90.
Smith, D.J., Oliver, C.E., Taylor, J.B., Anderson, R.C. 2012. Efficacy, metabolism, and toxic responses to chlorate salts in food and laboratory animals. Journal of Animal Science. 90:4098-4117.
Smith, D.J., Taylor, J.B. 2012. Kinetics and disposition of orally dosed sodium chlorate in sheep. Journal of Animal Science. 90:2026-2034.
Liu, Z., Zhang, Z., Faris, J.D., Oliver, R.P., Syme, R., Mcdonald, M.C., Mcdonald, B.A., Solomon, P.S., Lu, S., Shelver, W.L., Xu, S.S., Friesen, T.L. 2012. The cysteine rich necrotrophic effector SnTox1 produced by Stagonospora nodorum triggers susceptibility of wheat lines harboring Snn1. PLoS Pathogens. 8(1):e1002467.
Varel, V.H., Wells, J., Shelver, W.L., Rice, C., Armstrong, D.L., Parker, D.B. 2012. Effect of anaerobic digestion temperature on odour, coliforms and chlortetracycline in swine manure or monensin in cattle manure. Journal of Applied Microbiology. 112:705-715.
Shrestha, S.L., Casey, F.X.M., Hakk, H., Smith, D.J., Padmanabhan, G. 2012. Fate and transformation of an estrogen conjugate and its metabolites in agricultural soils. Environmental Science and Technology. 46:11047-11053.
Bai, X., Casey, F.X.M., Hakk, H., Desutter, T.M., Oduor, P.G., Khan, E. 2013. Dissipation and transformation of 17B-estradiol-17-sulfate in soil-water systems. Journal of Hazardous Materials. 260:733-739.