title: Joint acute toxicity of the herbicide butachlor and three insecticides to the terrestrial earthworm, Eisenia fetida.
abstract: The herbicide butachlor and three insecticides phoxim, chlorpyrifos, and lambda-cyhalotrhin are widely used pesticides with different modes of action. As most previous laboratory bioassays for these pesticides have been conducted solely based on acute tests with a single compound, only limited information is available on the possible combined toxicity of these common chemicals to soil organisms. In this study, we evaluated their mixture toxicity on the terrestrial earthworm, Eisenia fetida, with binary, ternary, and quaternary mixtures. Two different types of bioassays were employed in our work, including a contact filter paper toxicity test and a soil toxicity test. Mixture toxicity effects were assessed using the additive index method. For all of the tested binary mixtures (butachlor-phoxim, butachlor-chlorpyrifos, and butachlor-lambda-cyhalothrin), significant synergistic interactions were observed after 14 days in the soil toxicity assay. However, greater additive toxicity was found after 48 h in the contact toxicity bioassay. Most of the ternary and quaternary mixtures exhibited significant synergistic effects on the worms in both bioassay systems. Our findings would be helpful in assessing the ecological risk of these pesticide mixtures to soil invertebrates. The observed synergistic interactions underline the necessity to review soil quality guidelines, which are likely underestimating the adverse combined effects of these compounds.
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Cang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Ruixian
authors.initials: R
authors.lastname: Yu
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Shenggan
authors.initials: S
authors.lastname: Wu
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Xinju
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Agro-Product Quality and Safety of Ministry of Agriculture, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control / Key Laboratory for Pesticide Residue Detection of Ministry of Agriculture, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, China. caileiming2009@163.com.
authors.forename: Leiming
authors.initials: L
authors.lastname: Cai
mesh_terms: D000083:Acetanilides / Q000633:toxicity*; D000818:Animals; D004390:Chlorpyrifos / Q000633:toxicity; D004347:Drug Interactions; D006540:Herbicides / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D009570:Nitriles / Q000633:toxicity; D009835:Oligochaeta / Q000187:drug effects*; D009946:Organothiophosphorus Compounds / Q000633:toxicity; D010575:Pesticides / Q000633:toxicity; D011722:Pyrethrins / Q000633:toxicity; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000633:toxicity*; D018675:Toxicity Tests; D023382:Toxicity Tests, Acute
chemical_list: D000083:Acetanilides; D006540:Herbicides; D007306:Insecticides; D009570:Nitriles; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D011722:Pyrethrins; D012987:Soil; D012989:Soil Pollutants; C003135:phoxim; C054409:butachlor; D004390:Chlorpyrifos; C037304:cyhalothrin
keywords: Combined toxicity; Ecotoxicity; Pesticide; Soil organism