Toxicity Evaluation of Chlorpyrifos Metabolite 3,5,6-trichloro-2-pyridinol to Eisenia fetida in Different Soils

Abstract

The present study utilized a biomarker response method to evaluate the effect of 3,5,6-trichloro-2-pyridinol (TCP) in artificial and natural soils on Eisenia fetida after 7, 14, 28, 42 and 56 days exposure. Biomarker responses were standardized to calculate the Integrated Biomarker Response (IBR) index. The influence of soil type on TCP toxicity was assessed. Results indicated that TCP induced excessive reactive oxygen species, caused oxidative stress, DNA damage to earthworm, which is similar to its parent chemical chlorpyrifos. The IBR index of three enzymes activities showed that TCP induced the enzymes activities of earthworm in red clay was stronger than the other three soils. Specifically, chlorpyrifos exposure group showed a lower toxicity than TCP exposure group after 28 days exposure but a higher toxicity than TCP exposure group after 56 days exposure. Despite the deficiencies of this study, the above information is of great significance for assessing the risk of chlorpyrifos and its metabolite TCP pollution in soil ecosystems.