To investigate the relationships of trace element concentrations vs hematopoiesis and iron parameters, we measured lead, copper, zinc, cadmium, and ferritin levels in 251 healthy adolescents. Concentrations of trace metals were determined by atomic absorption spectrophotometry. There were no significant gender-related differences in serum copper or serum cadmium concentrations. However, blood lead and serum zinc levels were significantly higher in males than females (3.82+/- 1.24 and 118.4 +/- 43.7 microg/dl vs 2.86+/- 1.06 and 83.5+/- 35.2 microg/dl, p<0.05, respectively). Subjects with elevated lead and copper concentrations exhibited significantly higher leukocyte counts and significantly lower serum iron levels than those with decreased lead and copper concentrations, but no significant differences were observed in blood erythrocyte counts or hemoglobin levels between the 2 groups. Blood lead concentrations were 2-fold higher in male adolescents with leukocytes >9.1 x 10(3)/microl than in those with leukocytes <4.3 x 10(3)/microl (5.04+/- 1.67 microg/dl vs 2.51+/- 0.75 microg/dl, p<0.05). Leukocyte counts had significant correlations with blood lead (r=0.39, p<0.05) and serum copper (r=0.26, p<0.05) in males and zinc (r=0.28, p <0.05) in females. Serum iron levels were inversely correlated with blood lead and serum copper concentrations but were not correlated with serum zinc or cadmium levels. In short, blood lead and serum copper concentrations have important relationships to leukocyte counts and iron parameters in adolescents.