Difference of Mercury Contents of Divided Hair Fragments by Eating Food Contaminated with Organic Mercury Compounds

The Minamata disease is known since 1953 as an organic mercury intoxication, mainly among fishermen along the Minamata Bay, Kumamoto Prefecture, by eating seafoods contaminated with organic mercury compounds. In connection with the disease the mercury content in hair of the coastal residents of the Shiranui Sea was determined. By using the samples in which high contents were noted, the critical determinations were made by cutting the hair in 3 cm portions from the base and consequently remarkably uneven distributions of the mercury along the length were observed. The portions of hair with unusually high contents of mercury were presumed to grow during the uptake of the contaminated food. The application of this method to the residents of the contaminated area will be useful for better speculation of the period of contamination.