Accumulation and sublethal effects of triclosan and its transformation product methyl-triclosan in the earthworm Eisenia andrei exposed to environmental concentrations in an artificial soil

作者：Chevillot Fanny; Guyot Melanie; Desrosiers Melanie; Cadoret Nicole; Veilleux Eloise; Cabana Hubert; Bellenger Jean Philippe

来源：Environmental Toxicology and Chemistry, 2018, 37(7): 1940-1948.

DOI：10.1002/etc.4156

• Triclosan
• Methyl-triclosan
• Earthworms
• Reproduction assay
• Bioaccumulation

Municipal biosolids are increasingly used as a low-cost fertilizer in agricultural soil. Biosolids are contaminated by low concentrations (nanograms per gram dry wt range) of a large variety of organic contaminants, such as triclosan. The effect of exposure to low concentrations of organic contaminants on soil biota remains largely undocumented. We evaluated the sublethal effects of triclosan on the earthworm Eisenia andrei using an artificial soil amended with a nominal concentration of triclosan of 50ngg(-1) dry weight soil. Using a 56-d reproduction test, we monitored the effect of triclosan exposure on adult earthworm survival, growth, and reproduction. The bioaccumulation of triclosan in earthworm tissue (adults and juveniles) and degradation of triclosan were monitored. The genotoxicity of triclosan was evaluated using a comet assay (DNA damage) on adult earthworm coelomocytes. Exposure to a low concentration of triclosan had no significant effects on adult earthworm survival and DNA damage but significantly stimulated growth (p<0.05) by 2-fold compared with controls. It also significantly affected E. andrei reproduction parameters (p<0.05), as evidenced by an increase in the number of cocoons and juveniles and a decrease in the mean dry weight of juveniles. The bioaccumulation of triclosan in earthworms was moderate (bioaccumulation factor approximate to 2). In biosolid-borne trials, the bioaccumulation of methyl-triclosan in earthworm tissues was higher than that of the parent compound triclosan. We conclude that exposure to low concentrations of triclosan in artificial soil can significantly affect the growth and reproductive performance of earthworms (i.e., E. andrei). More research is required with natural soils to assess triclosan bioavailability for earthworms. Environ Toxicol Chem 2018;37:1940-1948.

• 出版日期2018-7