Abstract
This paper surveys the published literature on Ca–Pb interactions involving earthworms, and attempts to rationalize the information within a simple hypothetical scheme. The scheme recognises that Ca–Pb interactions operate within at least 3 major ‘compartments’: the geochemical or soil compartment; a metabolic or transport compartment; and in the cumulative or detoxification (chloragosome) compartment. The scheme also recognises that the consequences of Ca–Pb interactions differ under acidic and calcareous soil conditions. Finally, attention is drawn to those biotic and abiotic areas that require further study if earthworms are to be considered seriously for pollution monitoring purposes.