Mercury in human hair: a study of residents in Madrid, Spain.

The mercury content in hair of the population in Madrid (chosen randomly) was in the range of 1.29-129.47 micrograms/g (geometric mean = 7.96 micrograms/g). The mean mercury content in hair of occupationally exposed workers was 12.70 micrograms/g (range = 2.91-65.43 micrograms/g). The highest means, which were found in two families (i.e., 67.89 micrograms/g and 92.47 micrograms/g, Families A and B, respectively), probably resulted from external factors. No statistically significant variations in the mercury concentrations in hair were found with regard to sex, age, or dental fillings. A significant correlation (r = 0.785; P less than .01) was found between the concentration of the total mercury found in nursing infants and their mothers.