Comparisons of elemental concentrations in hair of the inhabitants of heavy metal polluted areas with those of normal Japanese, 2

The authors previously discussed the concentration differences and the correlation coefficients among the elements measured in hair samples collected from inhabitants living in areas polluted with mercury, arsenic or cadmium. In the present paper, the factor contributions and the factor loadings of the elements are estimated for each factor by making use of principal component analysis from the correlation coefficient matrix described in the previous paper. In order to examine the somatic effect of the contamination by heavy metals on individuals, the factor score of each sample is also obtained for each factor, where the sum of the multiples of elemental sample concentration and factor loading for the main 12 elements are calculated. For the first factor, the factor loadings of such elements as Ca, Mg, Zn and Cu are large, while those of Cl and Br are large in negative values. For the second factor, the factor loadings of such elements as K and Na are large. For the fifth factor, the factor loading of S is large, and S has little relation to other elements. These results are consistent with experimental results presented elsewhere. Unlike such experimental results, however, the present study suggests that Ca is one of the most correlated elements to the first factor. (Nogami, K.)