A refined aquatic ecological risk assessment for a pyrethroid insecticide used for adult mosquito management

• Published in: Environmental toxicology and chemistry Vol. 32; no. 4; pp. 948 - 953
• Main Authors: Schleier III, Jerome J., Peterson, Robert K.D.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.04.2013; SETAC; Blackwell Publishing Ltd
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Aquatic ecology; Aquatic insects; Aquatic organisms; Bioavailability; Biological and medical sciences; Culicidae; Dissolved organic matter; Ecotoxicology, biological effects of pollution; Fundamental and applied biological sciences. Psychology; General aspects; Insecticides; Insecticides - toxicity; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Models, Chemical; Mosquito Control - methods; Mosquito management; Mosquitoes; Nonnative species; Organic compounds; Organisms; Permethrin; Permethrin - toxicity; Pest control; Pest management; Pyrethrins - toxicity; Pyrethroid; Pyrethroids; Risk analysis; Risk assessment; Risk Assessment - methods; Ultralow volume; Vectors. Intermediate hosts; Water Pollutants, Chemical - toxicity; Pyrethroid; Ultralow volume; Insecticide; Ecotoxicology; Toxicity; Insecta; Pesticides; Parasite; Pyrethroids; Risk analysis; Pest management; Arthropoda; Culicidae; Mosquito management; Ectoparasite; Invertebrata; Diptera
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.2126

The use of pyrethroid insecticides has increased substantially throughout the world over the past few decades as the use of organophorous, carbamate, and organochlorine insecticides is being phased out. Pyrethroids are the most common class of insecticides for ultralow‐volume (ULV) aerosol applications used to manage high densities of adult mosquitoes. Pyrethroids are highly toxic to nontarget organisms such as certain aquatic organisms, and there have been concerns about the effect of applications of ULV insecticides on these organisms. To address the uncertainties associated with the risks of ULV applications and the contradictory findings of other ecological risk assessments, the authors performed a probabilistic aquatic ecological risk assessment for permethrin using actual environmental deposition on surfaces to estimate permethrin concentrations in water. The present study is the first ecological risk assessment for pyrethroids to quantitatively integrate the reduction in bioavailability resulting from the presence of dissolved organic matter. As part of the risk assessment, the authors incorporated a species sensitivity distribution to take into account the differences in toxicity for different species. The 95th percentile estimated concentration would result in less than 0.0001% of the potentially affected fraction of species reaching the lethal concentration that kills 50% of a population. The results of the present study are supported by the weight of evidence that pyrethroids applied by ground‐based ULV equipment will not result in deleterious effects on aquatic organisms. Environ. Toxicol. Chem. 2013;32:948–953. © 2013 SETAC