The influence of zinc on the uptake and loss of cadmium and lead in the woodlouse, Porcellio scaber (Isopoda, Oniscidea)

Uptake of cadmium, lead, and zinc was studied in juvenile Porcellio scaber in feeding experiments over 5 months. The metals mere offered separately an d in different combinations and concentrations in the food. The ability of P. scaber to eliminate the accumulated metals was studied subsequently for 3 months on uncontaminated food. Characteristic patterns of accumulation ar e described for the three metals. The combination of lead and zinc resulted in only minor differences in these patterns. On the other hand, the combin ation of zinc and cadmium at high concentrations completely changed the acc umulation patterns for both metals. Not only cadmium but also zinc was excr eted by P. scaber exclusively when the animals had been contaminated with b oth metals. In contrast both metals were stored permanently when offered se parately. Possible reasons for the interactions of cadmium and zinc are dis cussed. (C) 2000 Academic Press.