地熱発電所からのヒ素含有温水による河川汚染および人身影響

抄録

Health examination was carried out on subjects (2 males and 5 females) who used arsenic containing hot water from the geothermal power station in Kyushu, Japan. They used the hot water only to take a bath over 4 years. The arsenic concentration measured by the atomic absorption method after generating AsH₃ was 3.53μg/ml in the hot water. Waste water from the bath drained into a brook at the backyard and arsenic concentration in the brook were 0.54, 0.03 and 0.01μg/ml at the points of 0, 200 and 600m from the outlet, respectively.
A special health examination was carried out on the following items: 1) Physical examination by doctors (dermatologist and general physician) 2) blood examination 3) urine analysis 4) biochemical and enzymological serum examination by SMA-12 5) determination of arsenic in urine and hair.
Arsenic concentration in urine measured 3 times per day for each subject ranged from 58 to 178μg/l and it was within normal range, Arsenic concentration in hair was higher than normal range: the highest was 5.2μg/g, and for 5 of 7 subjects it was over 1μg/g. The result was suspected to be responsible for exogenous contamination such as washing of hair by hot water containing arsenic. There were no particular findings related to the arsenic poisoning.
It must be emphasized that special attention should be paid to prevent the environmental popllution and health hazard caused by the hot water from geothermal power stations.