Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington--Part II: controlled exposure studies.
Environ Toxicol Chem
; 34(11): 2542-8, 2015 Nov.
Article
em En
| MEDLINE
| ID: mdl-26351255
ABSTRACT
The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L(-1) , and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L(-1) . No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
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Crustáceos
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Imidazóis
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Inseticidas
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Nitrocompostos
Tipo de estudo:
Etiology_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Environ Toxicol Chem
Ano de publicação:
2015
Tipo de documento:
Article