The time-course of metal (Ca, Cd, Cu, Pb, Zn) accumulation from a contaminated soil by three populations of the earthworm, Lumbricus rubellus

Adult earthworms (Lumbricus rubellus), sampled from a metal-contaminated site (Cwmystwyth Cottage) and two reference sites (acidic, Caerffili; calcareous, Dinas Powys), were maintained on metalliferous Cwmystwyth Cottage soil in the laboratory for up to 90 days. All three populations accumulated Cd, Pb and Zn for at least the first 60 days of laboratory exposure, while Cu and Ca concentrations were maintained fairly constant throughout. The experiment did not prove conclusively that the native worms maintained on their own contaminated soil had the capacity to accumulate higher burdens of non-essential toxic metals (Cd and Pb) than the introduced reference worms. Finally, the reference population naturally inhabiting the Ca-poor acidic soil (Caerffili) accumulated or maintained tissue Ca concentrations more efficiently than the second reference population (Dinas Powys) and 'native' population (Cwmystwyth Cottage), both naturally inhabiting relatively Ca-rich soils. (C) 1999 Elsevier Science B.V. All rights reserved.