Pyrethroids are highly toxic to fish at parts per billion or parts per trillion concentrations. Their intended mechanism is prolonged sodium channel opening, but recent studies reveal that pyrethroids such as permethrin and bifenthrin also have endocrine activity. Additionally, metabolites may have greater endocrine activity than parent compounds. The authors evaluated the in vivo concentration...

Pyrethroids are a class of plant-derived insecticides and their man-made analogues that are increasingly applied in Canada as first choice for pest control in many agricultural and residential settings. Their popularity is partly due to their alleged safety compared to the older organochlorine and organophosphate insecticides. Application of pyrethroids is expanding because of recent increases ...

Pesticides can significantly harm reproduction in animals and people. Pyrethroids are often used as insecticides, and their toxicity for mammals is considered to be low. However, cypermethrin, deltamethrin and fenvalerate - as potent specific inhibitors of protein phosphatase calcineurin - can influence the meiosis of mammalian oocytes. The objective of this study was to evaluate the effects of...

Pyrethroid insecticides are used extensively in agriculture and in homes to control fleas, cockroaches, bedbugs, and other insects. In a new in vitro study researchers tested the hypothesis that mixtures of pyrethroids have a dose-additive effect—that is, that pyrethroids as a chemical group produce toxicity in mammals via a common mode of action and that the combined toxicity of a pyrethroid m...

Pyrethroid insecticides are used extensively in agriculture and in homes to control fleas, cockroaches, bedbugs, and other insects. In a new in vitro study researchers tested the hypothesis that mixtures of pyrethroids have a dose-additive effect—that is, that pyrethroids as a chemical group produce toxicity in mammals via a common mode of action and that the combined toxicity of a pyrethroid m...

Worldwide pesticide usage has increased dramatically during the past two decades, coinciding with changes in farming practices and increasingly intensive agriculture. Environmental pollution caused by pesticides, especially in aquatic ecosystems, has become a serious problem. Contamination of water by pesticides, either directly or indirectly, can lead to fish kills, reduced fish productivity, ...

Pyrethroid chemicals are attractive alternatives to the organophosphates (OPs) because of their selective toxicity against pests rather than mammals. The carboxylesterases (CEs) are hepatic enzymes that metabolize ester-containing xenobiotics such as pyrethroids. The primary aim of this study was to gain insight into the catalytic properties of the CE enzymes in humans that metabolize pyrethroi...

Due to extensive use, human exposure to multiple pyrethroid insecticides occurs frequently. Studies of pyrethroid neurotoxicity suggest a common mode of toxicity and that pyrethroids should be considered cumulatively to model risk. The objective of this work was to use a pyrethroid mixture that reflects human exposure to common pyrethroids to develop comparative toxicokinetic profiles in rats, ...