Plants as modifiers of cadmium bioavailability

Estimating maximum metal concentrations for soils that protect both plant a nd human health is difficult, because plants can influence the amount of me tal that is absorbed from soils or foods. Plant root accumulation of Cd, as well as translocation to shoots, is determined by internal physiological p rocesses, and is not dependent on the free ion concentration of Cd in the g rowing medium. Absorption of Cd from edible plants by the kidney or liver i s proportional to the dose, and is only slightly dependent on the form of C d in the diet. Plants dominate the biomass (and thus the diets) in many eco systems; their physiological processes must be considered in efforts to und erstand the transfer of metals among compartments of the environment.