title: Effects of phenanthrene on the mortality, growth, and anti-oxidant system of earthworms (Eisenia fetida) under laboratory conditions.
abstract: To assess the toxic effects of phenanthrene on earthworms, we exposed Eisenia fetida to artificial soils supplemented with different concentrations (0.5, 2.5, 12.5, mgkg(-1) soil) of phenanthrene. The residual phenanthrene in the soil, the bioaccumulation of phenanthrene in earthworms, and the subsequent effects of phenanthrene on growth, anti-oxidant enzyme activities, and lipid peroxidation (LPO) were determined. The degradation rate of low concentrations of phenanthrene was faster than it was for higher concentrations, and the degradation half-life was 7.3d (0.5 mgkg(-1)). Bioaccumulation of phenanthrene in the earthworms decreased the phenanthrene concentration in soils, and phenanthrene content in the earthworms significantly increased with increasing initial soil concentrations. Phenanthrene had a significant effect on E. fetida growth, and the 14-d LC(50) was calculated as 40.67 mgkg(-1). Statistical analysis of the growth inhibition rate showed that the concentration and duration of exposure had significant effects on growth inhibition (p<0.001). Superoxide dismutase (SOD) activity increased at the beginning (2 and 7d) and decreased in the end (14 and 28 d). Catalase (CAT) activity in all treatments was inhibited from 1 to 14 d of exposure. However, no significant perturbations in malondialdehyde (MDA) content were noted between control and phenanthrene-treated earthworms except after 2d of exposure. These results revealed that bioaccumulation of phenanthrene in E. fetida caused concentration-dependent, sub-lethal toxicity. Growth and superoxide dismutase activity can be regarded as sensitive parameters for evaluating the toxicity of phenanthrene to earthworms.
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
authors.forename: Shijin
authors.initials: S
authors.lastname: Wu
authors.forename: Ermiao
authors.initials: E
authors.lastname: Wu
authors.forename: Lequan
authors.initials: L
authors.lastname: Qiu
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhong
authors.forename: Jianmeng
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D006131:Growth Inhibitors / Q000378:metabolism / Q000633:toxicity; D008315:Malondialdehyde / Q000378:metabolism; D009835:Oligochaeta / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D010616:Phenanthrenes / Q000378:metabolism / Q000633:toxicity*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D006131:Growth Inhibitors; D010616:Phenanthrenes; D012989:Soil Pollutants; C031181:phenanthrene; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase