Monograph Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating the Impact?
BibTeX
@MISC{Hayes_monographpesticide,
author = {Tyrone B. Hayes and Sarah Chui and Duc Chung and Cathryn Haeffele and Kelly Haston and Melissa Lee and Vien Phoung Mai and Youssra Marjuoa and John Parker and Mable Tsui},
title = {Monograph Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating the Impact?},
year = {}
}
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Abstract
Amphibian populations are declining globally at an alarming rate. Pesticides are among a number of proposed causes for these declines. Although a sizable database examining effects of pesticides on amphibians exists, the vast majority of these studies focus on toxicological effects (lethality, external malformations, etc.) at relatively high doses (parts per million). Very few studies focus on effects such as endocrine disruption at low concentrations. Further, most studies examine exposures to single chemicals only. The present study examined nine pesticides (four herbicides, two fungicides, and three insecticides) used on cornfields in the midwestern United States. Effects of each pesticide alone (0.1 ppb) or in combination were examined. In addition, we also examined atrazine and S-metolachlor combined (0.1 or 10 ppb each) and the commercial formulation Bicep II Magnum, which contains both of these herbicides. These two pesticides were examined in combination because they are persistent throughout the year in the wild. We examined larval growth and development, sex differentiation, and immune function in leopard frogs (Rana pipiens). In a follow-up study, we also examined the effects of the nine-compound mixture on plasma corticosterone levels in male African clawed frogs (Xenopus laevis). Although some of the pesticides individually inhibited larval growth and development, the pesticide mixtures had much greater effects. Larval growth
Keyphrases
endocrine disruption larval growth amphibian decline monograph pesticide mixture low concentration immune function amphibian exists sex differentiation sizable database nine-compound mixture pesticide mixture leopard frog vast majority high dos xenopus laevis amphibian population toxicological effect midwestern united state present study commercial formulation bicep ii magnum proposed cause follow-up study external malformation plasma corticosterone level single chemical
