Dataset Information

The fungicide chlorothalonil is nonlinearly associated with corticosterone levels, immunity, and mortality in amphibians.

ABSTRACT:

Background

Contaminants have been implicated in declines of amphibians, a taxon with vital systems similar to those of humans. However, many chemicals have not been thoroughly tested on amphibians or do not directly kill them.

Objective

Our goal in this study was to quantify amphibian responses to chlorothalonil, the most commonly used synthetic fungicide in the United States.

Methods

We reared Rana sphenocephala (southern leopard frog) and Osteopilus septentrionalis (Cuban treefrog) in outdoor mesocosms with or without 1 time (1×) and 2 times (2×) the expected environmental concentration (EEC) of chlorothalonil (~ 164 ?g/L). We also conducted two dose-response experiments on O. septentrionalis, Hyla squirella (squirrel treefrog), Hyla cinerea (green treefrog), and R. sphenocephala and evaluated the effects of chlorothalonil on the stress hormone corticosterone.

Results

For both species in the mesocosm experiment, the 1× and 2× EEC treatments were associated with > 87% and 100% mortality, respectively. In the laboratory experiments, the approximate EEC caused 100% mortality of all species within 24 hr; 82 ?g/L killed 100% of R. sphenocephala, and 0.0164 ?g/L caused significant tadpole mortality of R. sphenocephala and H. cinerea. Three species showed a nonmonotonic dose response, with low and high concentrations causing significantly greater mortality than did intermediate concentrations or control treatments. For O. septentrionalis, corticosterone exhibited a similar nonmonotonic dose response and chlorothalonil concentration was inversely associated with liver tissue and immune cell densities (< 16.4 ?g/L).

Conclusions

Chlorothalonil killed nearly every amphibian at the approximate EEC; at concentrations to which humans are commonly exposed, it increased mortality and was associated with elevated corticosterone levels and changes in immune cells. Future studies should directly quantify the effects of chlorothalonil on amphibian populations and human health.

SUBMITTER: McMahon TA

PROVIDER: S-EPMC3237349 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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Publications

The fungicide chlorothalonil is nonlinearly associated with corticosterone levels, immunity, and mortality in amphibians.

McMahon Taegan A TA Halstead Neal T NT Johnson Steve S Raffel Thomas R TR Romansic John M JM Crumrine Patrick W PW Boughton Raoul K RK Martin Lynn B LB Rohr Jason R JR

Environmental health perspectives 20110404 8

<h4>Background</h4>Contaminants have been implicated in declines of amphibians, a taxon with vital systems similar to those of humans. However, many chemicals have not been thoroughly tested on amphibians or do not directly kill them.<h4>Objective</h4>Our goal in this study was to quantify amphibian responses to chlorothalonil, the most commonly used synthetic fungicide in the United States.<h4>Methods</h4>We reared Rana sphenocephala (southern leopard frog) and Osteopilus septentrionalis (Cuban ...[more]

PMID: 21463979

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Dataset Information

The fungicide chlorothalonil is nonlinearly associated with corticosterone levels, immunity, and mortality in amphibians.

Background

Objective

Methods

Results

Conclusions

Publications

The fungicide chlorothalonil is nonlinearly associated with corticosterone levels, immunity, and mortality in amphibians.

Similar Datasets

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