Assessment of accumulated body burden of metals.

Knowledge of the body burden of a metal is important for evaluation of exposure and risk. Traditionally, the burden has been estimated through levels in blood, urine, hair, or shed teeth, or by mobilization tests. However, all these methods have limitations. In vivo methods for determination of cadmium in kidney by neutron activation analysis or X-ray fluorescence (XRF) reflect the burden, long-term exposure, and risk of toxic effect. In vivo determination by XRF of lead in fingerbone, tibia, or calcaneus reflect the long-term exposure, and should become a valuable tool in epidemiological studies, especially of chronic effects.