Zinc, cadmium, lead and copper in sweat from 24 male and 39 female volunteers were determined by anodic stripping voltammetry. Sweating was induced on the forearms by pilocarpine iontophoresis. Average values found for zinc, cadmium, lead and copper in sweat from males were 181 (range 25-863), 1.4 (less than 0.5-10), 41 (6-87) and 103 (less than 5-673) micrograms l-1, respectively. Zinc in sweat from females was significantly higher than in sweat from males (331 micrograms l-1, range 87-836 micrograms l-1), while sweat copper and sweat lead in females were lower (29 micrograms Cu l-1, range less than 5-146 micrograms Cu l-1 and 24 micrograms Pb l-1, range less than 5-66 micrograms Pb l-1). Those taking oral contraceptives showed increased sweat copper concentrations (94 micrograms Cu l-1, range less than 5-480 micrograms Cu l-1) and sweat lead concentrations (36 micrograms Pb l-1, range less than 5-70 micrograms Pb l-1). There was no sex-based difference for copper in sauna-induced sweat. Metal concentrations in sweat were compared with ceruloplasmin, alkaline phosphatase, and total and mobile copper and zinc concentrations in serum in males and females.