|Abstract Title:||Health Impairment in the Opposite Coastal Area of Yatsushiro Sea|
|Presenter Name:||Shigeru Takaoka|
|Company/Institution:||Kyoritsu Neurology & Rehabilitation Clinic|
|Session:||Human Exposure and Risk Assessment of Hg|
Abstract Information :
The health effects caused by methylmercury pollution have been supposed to spread throughout Yatsushiro Sea. This paper aims to grasp the actual condition and degree of the health impairments in the opposite coastal region from Minamata in the coastal region of Yatsushiro Sea. We performed research on residential history, occupational history, family history, and eating habit, inquiry of the subjective symptom, neurological examination of the tactile and pain sensation, and quantitative sensory examination by von Frey monofilaments and C tuning fork in residents who were born by December 1968. The surveyed contaminated areas were Miyanokawachi, Amakusa City (2015, western part of Yatsushiro Sea), Himedo, Kami-Amakusa City (2016, northern part), Nagashima Town (2017, southern part). Control area was Yamato Town in Amami Islands. Excluding those who had no history of residence in the area or who had a history of residence in the nearer and more contaminated area from Minamata in the period from 1953 to 1968, examined residents were 70 (M/F=35/35, Average Age 69.9ñ10.8) in Miyanokawachi, 89 (M/F=45/44, 71.4ñ11.4) in Himedo, 45(M/F=29/16, 68.3ñ10.3) in Nagashima, and 70 (M/F=21/49, 71.9ñ9.9) in Amami, respectively. The prevalence of people with four-limb dominant somatosensory disturbance was 58.8% in Miyanokawachi, 53.9% in Himedo 37.8% in Nagashima, and 1.4% in Amami. The prevalence was 24.4%, 26.7%, 16.7% among whole population, respectively in the polluted areas. Observing four-limb dominant sensory disturbance in these areas, attributable fractions of pollution in the polluted areas were, 94.1% in Miyanokawachi, 94.6% in Himado, and 91.4% in Nagashima. When we use whole body sensory disturbance, the attributable fractions were also high. In the quantitative sensory examination, the sensory acuities were disturbed in the whole body in the almost similar order, and the significant difference were recognized from Amami. The health impairment by methylmercury in Yatsushiro Sea spread over the entire coastal area.