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Percutaneous malathion absorption by anuran skin in flow-through diffusion cells.
Scott Willens1, Michael K Stoskopf, Ronald E Baynes
1Environmental Medicine Consortium, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Environmental Toxicology and Pharmacology
|July 26, 2011
Summary
Organophosphorus pesticides like malathion pose risks to amphibians. This study found malathion is absorbed more readily through the ventral skin of frogs and toads compared to their dorsal skin.
Area of Science:
- Environmental Toxicology
- Amphibian Physiology
- Pesticide Research
Background:
- Organophosphorus (OP) compounds are linked to adverse health effects in animals.
- Amphibians are particularly vulnerable to environmental contaminants like malathion.
- Cutaneous absorption is a significant exposure route for amphibians in aquatic environments.
Purpose of the Study:
- To determine the cutaneous absorption kinetics of malathion in amphibians.
- To compare malathion absorption rates between dorsal and ventral skin surfaces.
- To assess the role of skin absorption in amphibian exposure to environmental pesticides.
Main Methods:
- Utilized an in vitro flow-through diffusion cell system with amphibian skin samples.
- Applied a radiolabeled malathion dose to full-thickness dorsal and ventral skin of bullfrogs and marine toads.
- Collected and analyzed perfusate over 6 hours to quantify malathion absorption and residues.
Main Results:
- Malathion absorption was significantly greater across the ventral skin compared to the dorsal skin in both species.
- Demonstrated differential absorption rates based on skin location.
- Quantified malathion absorption kinetics through amphibian skin in vitro.
Conclusions:
- Ventral skin presents a more permeable barrier to malathion absorption in anurans.
- Findings highlight the importance of skin location in amphibian pesticide exposure risk assessment.
- Supports the concern for sublethal effects of organophosphorus pesticides on amphibian populations.
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