title: Pesticide Uptake Across the Amphibian Dermis Through Soil and Overspray Exposures.
abstract: For terrestrial amphibians, accumulation of pesticides through dermal contact is a primary route of exposure in agricultural landscapes and may be contributing to widespread amphibian declines. To show pesticide transfer across the amphibian dermis at permitted label application rates, our study was designed to measure pesticide body burdens after two simulated exposure scenarios. We compared direct exposures, where amphibians were present when spraying occurred, to indirect exposures, where amphibians were exposed to soils after pesticide application. During summer 2012, we reared barking (Hyla gratiosa) and green treefrogs (H. cinerea) through 60-90 days post-metamorphosis at a United States Environmental Protection Agency research laboratory. We tested exposure for 8 h to five pesticide active ingredients (imidacloprid, atrazine, triadimefon, fipronil, or pendimethalin) in glass aquaria lined with soil in the laboratory. We quantified total pesticide body burden and soil concentrations using liquid chromatography-mass spectrometry. All individuals in both treatments had measurable body burdens at the end of the study. A randomized block design analysis of variance (n = 18) showed that body burdens (p = 0.03) and bioconcentration factors (BCFs) (p = 0.01) were significantly greater in the direct overspray treatment relative to the indirect soil spray treatment for both species and tested pesticides. BCFs ranged from 0.1 to 1.16 and from 0.013 to 0.78 in the direct and indirect treatments, respectively. Our study shows dermal uptake for multiple pesticides from both direct spray and indirect soil exposures and provides empirical support for the degree to which terrestrial phase amphibians have higher body burdens after overspray pesticide exposure.
authors.affiliation: Oak Ridge Institute of Science and Education, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA. rvanmeter2@washcoll.edu.|Washington College, Toll Science Center SG20, Chestertown, MD, 21620, USA. rvanmeter2@washcoll.edu.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Van Meter
authors.affiliation: Student Services Authority Contractor, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA.
authors.forename: Donna A
authors.initials: DA
authors.lastname: Glinski
authors.affiliation: Ecosystems Research Division, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA.
authors.forename: W Matthew
authors.initials: WM
authors.lastname: Henderson
authors.affiliation: Ecosystems Research Division, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA.
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Garrison
authors.affiliation: Ecosystems Research Division, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA.
authors.forename: Mike
authors.initials: M
authors.lastname: Cyterski
authors.affiliation: Ecosystems Research Division, United States Environmental Protection Agency, 960 College Station Road, Athens, GA, 30605, USA.
authors.forename: S Thomas
authors.initials: ST
authors.lastname: Purucker
mesh_terms: D000383:Agriculture / Q000379:methods; D000663:Amphibians / Q000378:metabolism*; D000818:Animals; D020405:Dermis; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D008675:Metamorphosis, Biological; D010575:Pesticides / Q000378:metabolism*; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry
chemical_list: D010575:Pesticides; D012987:Soil