Metallothionein responses in the earthworm Lampito mauritii (Kinberg) following lead and zinc exposure: A promising tool for monitoring metal contamination

Biomarkers allow the evaluation of possible biochemical effects under various metal contaminations in the terrestrial environment. In order to attain this objective adult, sexually mature Lampito mauritii were exposed to different concentrations of lead (Pb) and zinc (Zn) separately for 28 days and concentrations of metallothionein were assessed by radioassay method using Hg-203. A significant increase in tissue metallothionein level was recorded in L. mauritii exposed to Pb and Zn contaminated soil. Thus it may be surmised that metallothioneins are directly involved in metal ion detoxification and helps L. mauritii to survive in metal contaminated soil. Moreover the sensitivity of this biochemical parameter observed in L. mauritii exposed to Pb and Zn can be used as reliable biomarker in monitoring metal pollution. (C) 2010 Elsevier Masson SAS. All rights reserved.