Environmental Fate of Pyrethroids

Pyrethroids can also persist in sediments. In one study, alpha-cypermethrin was applied to a pond as an emulsifiable concentrate (Environmental Health Criteria 142). After 16 days of application, 5% of the applied dose was still present in sediment, falling to 3% after a further 17 days. This suggests a half-life of the order of 20-25 days—comparable in magnitude to half-lives measured in temperate soils. 

The general picture, then, is that pyrethroids are reasonably persistent in soils and sediments but not to the same degree as OC compounds such as dieldrin and p,p -DDE. They do undergo bioconcentration from water by fish and other aquatic 

Organic Pollutants An Ecotoxicological Perspective, Second Edition 

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