Utilizing information obtained from the X-ray fluores-cence linear scanning along a single strand of hair in a recent fatal exposure to dimethylmercury, it was possible to determine the circumstances leading to the fatal result. When the Dartmouth chemistry professor displayed symptoms of mercury toxicity, samples of her urine and blood were found to have considerable amounts of mercury by a commercial laboratory. The Dartmouth medical people immediately started treatment with a chelator on January 29, 1997 to remove the mercury, and sent the first samples of blood, urine and hair taken on January 31, 1997 to our laboratory. Our X-ray fluorescence analysis of a single strand of hair shown in Figure 1 shows a single large peak of intake of mercury confirming the information revealed by examination of her laboratory notebook that she had spilled some dimethylmercury about 5 months previous to the date the hair sample was taken. Figure 2 shows two peaks, the peak closest to the scalp end of the hair shows the effect of the large amount of mercury released by the chelator, part of which appeared in the blood. Utilizing the start of the first increase in the blood level as August 14, 1996, and the second as caused by the chelator on January 29, 1997, a count of the number of 2-mm points measured between the two dates gives an accurate growth of the hair during that time. A close examination of Figure 1 indicates that it required five points, each of 2 mm, along the hair to reach the maximum. This indicates a time period of 10 mm of growth equal to 23 days during which a large concentration of methylmercury was entering the blood as evidenced by the hair concentration. The professor died on June 11, 1997.
