STUDIES ON CHANGES OF ELEMENTAL CONCENTRATION IN A HUMAN BODY BY MEANS OF ANALYSES OF LONG HAIRS BASED ON THE STANDARD-FREE METHOD

Abstract

We established and reported two years ago the original methods for evaluating daily changes of elemental concentration in a body by means of a standard-free method for powdered beard samples daily taken with electric shaver. It was found that the method is quite useful for investigating short- and long-term changes of elemental concentration in a body. However, the method for beard analysis is applicable only to men. In order to estimate daily changes of elemental concentration in a body for women and children, a new method which allows us to quantitatively analyze hair samples cut into 1 mm pieces has been developed and applied to three long hair samples taken from three persons. It is found that the method enables us to estimate both long- and short-term changes in elemental concentration in a body as well as beard analysis. It is found that sulfur keeps almost constant over a long period, and arsenic shows very rapid changes with a few days' period, while mercury shows only long-term changes with the period of a few months. These behaviors are almost the same as those observed in beard analyses. On the other hand, bromine shows a certain seasonal changes; its concentration shows a certain trend of increasing in summer and decreasing in winter. Lead and calcium show very long-term changes, and the behavior of strontium is quite similar to that of calcium. The method is expected to give us information about history of changes in elemental concentration in a human body over a few or more years. It is expected that the behavior of arsenic showing rapid elevation within a few days can be explained as a response to intakes of arsenic-rich foods. It is expected that the method gives us a clue to the identification of the main pathways of human exposure to certain toxic elements.