The effects of earthworm maturity on arsenic accumulation and growth after exposure to OECD Soils containing mine tailings

Abstract

Earthworm, Eisenia fetida, was exposed for 14 days to OECD soils mixed with As-contaminated mine tailings. Prior to exposure, earthworms were divided into three growth states (mature, formative, and immature) with both the development of clittellum and body weight. Toxic effects on growth of immature earthworms were caused by 5 and 10% proportions of mine tailings in OECD soils, while mature or formative ones did not show any adverse effects on growth. Moreover, only immature worms exposed to OECD soils with 10% mine tailings resulted in the loss of body weight, which was contrast to the result that body weights of immature worms increased mostly when exposed to the control. Arsenic concentrations in earthworms increased for 14-day exposure. Arsenic uptake patterns did not show any difference with the initial earthworm maturity. Arsenic accumulations were dependent on not the maturity but the proportion of mine tailings in OECD soils. The results implied that earthworm has an ability to resist As toxicity, and the degree of tolerance to As may differ with maturity. Young earthworms were more easily affected by As than mature worms. © 2009 Springer Netherlands.