Activation analysis of mercury in head hair of dentists

Mercury contents in head hair of 58 dentists, working at the hospital of Nihon University School of Dentistry, were determined using neutron activation analysis. The values ranged from 2.47 ppm to 13.7 ppm. The frequency distribution of the mercury contents increased steeply at about 2 ppm to the maximum of 4 -- 5 ppm, and decreased to about 11 ppm, its distribution pattern followed a log-normal one with a median of 5.46 ppm. The dentists were divided into two groups and the mercury contents in head hair of them were compared with each other. The arithmetic and geometric means of the values for dentists who handled amalgam in dental practice were 5.66 ppm (SD +- 1.80) and 5.40 ppm (SD x/ 1.36), while those for the dentists who did not handle amalgam in dental practice were 5.96 ppm (SD +- 2.82) and 5.38 ppm (SD x/ 1.59). The values of them agreed well with each other. The arithmetic mean for all dentists was 5.79 ppm (SD +- 2.28) and the geometric mean of them was 5.40 ppm (SD x/ 1.46). They were much lower than the values reported by Suzuki, Miyazawa or Sairenji, et al. in the past year, and they agreed well to those for normal Japanese men with the same age. Therefore it is concluded that proper mercury handling might be established in the dental office. (author)