The excretion of trace metals in human sweat.

The concentrations of zinc, copper, iron, nickel, cadmium, lead, manganese, sodium and chloride in the sweat of six males and three females were determined after collections utilizing a total body washdown technique. From our results, sweat appears to be an important excretory pathway for zinc and copper. The mean concentrations of nickel and cadmium in sweat were higher than those reported for urine, that of lead was similar to urine. The loss of manganese in sweat is significant. Levels of zinc and iron were lower in sweat from females, possibly reflecting compensation for menstrual and other losses. Collections were made in six subjects simultaneously utilizing a total body washdown method and collections from one arm in an occlusive arm-bag. The arm-bag collection method gave higher and more variable results and is not recommended as an indicator of loss from the entire skin surface.