title: Lethal and sub-lethal effects of five pesticides used in rice farming on the earthworm Eisenia fetida.
abstract: The toxicity of five pesticides typically used in rice farming (trichlorfon, dimethoate, carbendazim, tebuconazole and prochloraz) was evaluated on different lethal and sub-lethal endpoints of the earthworm Eisenia fetida. The evaluated endpoints included: avoidance behaviour after an exposure period of 2 days; and mortality, weight loss, enzymatic activities (cholinesterase, lactate dehydrogenase and alkaline phosphatase) and histopathological effects after an exposure period of 14 days. Carbendazim was found to be highly toxic to E. fetida (LC50=2mg/kg d.w.), significantly reducing earthworm weight and showing an avoidance response at soil concentrations that are close to those predicted in rice-fields and in surrounding ecosystems. The insecticide dimethoate showed a moderate acute toxicity (LC50=28mg/kg d.w.), whereas the rest of tested pesticides showed low toxicity potential (LC50 values above 100mg/kg d.w.). For these pesticides, however, weight loss was identified as a sensitive endpoint, with NOEC values approximately 2 times or lower than the calculated LC10 values. The investigated effects on the enzymatic activities of E. fetida and the observed histopathological alterations (longitudinal and circular muscle lesions, edematous tissues, endothelial degeneration and necrosis) proved to be sensitive biomarkers to monitor pesticide contamination and are proposed as alternative measures to evaluate pesticide risks on agro-ecosystems.
authors.affiliation: IMDEA Water Institute, Science and Technology Campus of the University of Alcalá, Avenida Punto Com 2, P.O. Box 28805, Alcalá de Henares, Madrid, Spain; Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, The Netherlands. Electronic address: andreu.rico@imdea.org.
authors.forename: Andreu
authors.initials: A
authors.lastname: Rico
authors.affiliation: Departament de Biotecnologia, Universitat Politècnica de València, Camino de Vera, 14, 46022 Valencia, Spain.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Sabater
authors.affiliation: Departament de Biotecnologia, Universitat Politècnica de València, Camino de Vera, 14, 46022 Valencia, Spain.
authors.forename: María-Ángeles
authors.initials: MÁ
authors.lastname: Castillo
mesh_terms: D000383:Agriculture; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002802:Cholinesterases / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology / Q000633:toxicity*; D045022:Lactate Dehydrogenases / Q000378:metabolism; D009835:Oligochaeta / Q000187:drug effects*; D010575:Pesticides / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D007306:Insecticides; D010575:Pesticides; D012989:Soil Pollutants; D045022:Lactate Dehydrogenases; D002802:Cholinesterases; D000469:Alkaline Phosphatase
keywords: Biomarkers; Eisenia fetida; Histological examination; Pesticides; Terrestrial ecotoxicology