ICMGP 2022 – On-Demand / Poster Presentation

Abstract Information :

From the medical records of two medical institutions in Niigata, we counted the number of people who had ingested fish contaminated with methylmercury and had sensory disturbances of peripheral predominance in the extremities, and counted them in each village where they lived in 1965 when Niigata Minamata disease was confirmed. In the villages where the population in 1965 was known, those with sensory disturbances of peripheral predominance in the extremities were considered to be prevalent, and the remaining population was assumed to be free of sensory disturbances of peripheral limb predominance. As a result, it was found that the target villages existed in the entire area from the mouth of the Agano River to Kanose Town, where the Showa Denko Kanose Plant, which emits methyl mercury, is located 64 km upstream. In one study, 1270 elderly people aged 60 years or older were examined for sensory disturbances in the peripheral extremities. Three of the subjects showed sensory disturbances in the peripheral predominance of the extremities. Comparing those with symptoms (2,381) and without symptoms (42,992) in the exposed area, and those with symptoms (3) and without symptoms (1267) in the unexposed area, the odds ratio was 23.4 (95% confidence interval 7.5-72.7), and the exposed group contributing risk percentage was 95.7%. It was found that those who had peripheral predominant sensory disturbances in this area were mostly affected by methylmercury. Niigata Minamata disease is methylmercury poisoning. Many of the victims had been eating fish contaminated with methyl mercury for more than a year. At present, there are more than 70,000 people who have been found to have sensory disturbances with peripheral limb dominance, but only about 3,000 have been recognized by the Japanese government as victims of methylmercury poisoning (Minamata disease patients).