Toxic effects of brominated flame retardants and insecticides on Scenedesmus obliquus
In order to clarify the toxic effects of brominated flame retardants and insecticides on microalgae,the present study investigated the single and combined toxicity of three brominated flame retardants(BFRs),three neonicotinoid insecticides(NNIs),and three organophosphorus insecticides(OIs)to microalgae.The results showed that both single and mixed systems of BFRs,NNIs and QIs induced the hormetic effect in the form of promotion at low concentrations and inhibition at high concentrations in S.obliquus.The hormetic effect was closely related to intracellular reactive oxygen species(ROS)levels.A moderate growth in ROS level promoted the growth of microalgae and might even lead to the generation of bloom,while a significant growth in ROS inhibited the growth of microalgae.Predicting no-effect concentrations(PNECs)for all nine pollutants were within the lagged stimulus interval,suggesting that the PNEC values predicted by the dose-effect curves overestimated the risk of the pollutants to aquatic ecosystems.Based on the independent action model(IA),it was found that the combined toxicity of 18 binary mixing systems on S.obliquus had a concentration-dependent effect.
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维普
