Arsenic, cadmium, and lead levels were determined simultaneously in multiple environmental media and human tissues in two zinc smelter (Bartlesville, Oklahoma and Palmerton, Pennsylvania) and two copper smelter (Ajo, Arizona and Anaconda, Montana) communities. Environmental media sampled included air, soil, household dust, and tap water; human samples included hair, blood, and urine. Between 200 and 300 residents from various age groups (1-5, 6-18, 20-40, and 60 + yr) were sampled in 1978 and 1979 and completed questionnaires in each of the four communities. Samples for all media were selected under a probability sampling framework at various distances from the smelters. Results of this investigation indicated that increased environmental levels and body burdens were exhibited at distances closest to the smelters. Of the three tissues sampled, hair was the most useful in determining relationships between environmental metal levels, distance, and body burden. Furthermore, while there was evidence that all ages had hair metal levels that were related to environmental levels and distance from the smelter, these relationships were much more pronounced for the 1- to 5-yr-old age group. The 1 to 5 yr olds also had the highest tissue metal levels across age groups. Higher hair metal levels were also found for males; smokers; children who ate paint, dirt, or clay; and for individuals who spent more time out of doors.