“…They were not, however, able to quantify the results, partly because of the difficulty in determining the mass of the hair being irradiated (effective mass) and of correcting for x-ray attenuation in the sample. In this article we report an extension of a mass determination technique which was previously published (Zeitz 1969, Kubo et a1 1978, Kubo and Smythe 1979 on the quantitative analysis of trace elements in hair.…”