trace metal levels and environmental exposure

environmental exposure in a study of fourth-grade boys in cities representing exposure dose gradients for arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn). Hair samples were carefully and stringently washed before analysis for As by spectrophotometry and for Cd, Cu, Pb, and Zn by atomic ab-sorption spectroscopy. Hair trace metal distributions for As, Cd, Cu, and Pb were positively skewed while those for Zn were symmetrical. Means were in accord with exposure rankings for As, Cd, and Pb but not for Cu and Zn. When grouped across a ranking gradient, differences among the means for As, Cd, and Pb were statis-tically significant while those of Cu and Zn were not. The present study minimized possible effects of age, sex, hair color, varying hair length, and chemical treat-ments. Despite the problems of exogenous deposition, endogenous absorption routes, and relationships of hair metal to body burden, mean hair metals levels for As, Cd, and Pb accurately reflected community exposures. air pollution; arsenic; cadmium; copper; environmental exposure; hair; lead; zinc INTRODUCTION for metallic environmental pollutants (1)