Acute Toxicity and Tissue Distributions of Malathion in Ambystoma tigrinum

• Published in: Archives of environmental contamination and toxicology Vol. 55; no. 3; pp. 481 - 487
• Main Authors: Henson-Ramsey, H., Kennedy-Stoskopf, S., Levine, J. F., Taylor, S. K., Shea, D., Stoskopf, M. K.
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01-10-2008; Springer Nature B.V
• Subjects: Acute toxicity; Ambystoma - growth & development; Ambystoma - metabolism; Ambystoma tigrinum; Animal, plant and microbial ecology; Animals; Applied ecology; Bioaccumulation; Biological and medical sciences; Biological magnification; Body Burden; Brain - drug effects; Brain - enzymology; Brain - metabolism; Caudata; Cholinesterase; Cholinesterases - metabolism; Chromatography; Earth and Environmental Science; Ecotoxicology; Ecotoxicology, biological effects of pollution; Environment; Environmental Chemistry; Environmental Health; Exposure; Food Chain; Food contamination & poisoning; Fundamental and applied biological sciences. Psychology; Gas chromatography; General aspects; Ingestion; Malathion; Malathion - pharmacokinetics; Malathion - toxicity; Monitoring/Environmental Analysis; Oligochaeta - metabolism; Pesticides; Pollution; Polyethylene; Reptiles & amphibians; Soil contaminants; Soil contamination; Soil Pollutants - pharmacokinetics; Soil Pollutants - toxicity; Soil Science & Conservation; Soil surfaces; Studies; Tissue Distribution; Toxicity; Worms; Malathion; Bioaccumulation; Cholinesterase; Bioaccumulation Factor; Unexposed Control; Insecticide; Ecotoxicology; Toxicity; Caudata; Acute; Pesticides; Amphibia; Vertebrata; Pollution; Environment; Organophosphorus compounds; Ambystoma tigrinum
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-007-9091-4

The kinetics of the bioaccumulation of malathion (
O,O
-dimethyl phosphorodithioate of diethyl mercaptosuccinate) and the biological impact of exposure for tiger salamanders,
Ambystoma
tigrinum
, were assessed through exposure to soil surface contaminated with 50 μg/cm
2
or 100 μg/cm
2
malathion and ingestion of an earthworm exposed to soil contaminated with 200 μg/cm
2
malathion. Malathion and malaoxon burdens in salamanders sampled at different times after exposure(s) were measured by gas chromatography in four tissue/organ subgroups: liver, epaxial muscle, pooled viscera (except the liver and brain), and pooled avisceral carcass (muscle, skin, and bone). The total tiger salamander xenobiotic burdens were calculated from these data. The malathion/malaoxon burden 1 day after exposure was greatest in the avisceral carcass and 2 days after exposure was greatest in the viscera. Bioconcentration and bioaccumulation factors remained less than unity throughout the experiment and did not support the hypothesis of bioaccumulation of malathion in the tiger salamander. Biological impact was assessed with a colorimetric brain cholinesterase microassay. Brain cholinesterase activities in salamanders exposed to malathion-contaminated soil (50 μg/cm
2
or 100 μg/cm
2
malathion) were suppressed ∼50–65% and 90%, respectively, compared to unexposed controls. The exposed animals did not exhibit overt clinical signs of malathion toxicosis.