| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Mercury contents of samples of sea water, and sediments and shellfish at seashores from Sakurajima Island and Minamata-Fukuro Bay were measured to find mercury levels in their environments. Mercury contents of sea water samples at 26 stations in Kagoshima Bay were also analyzed for their seasonal and local variations. Moreover, contents of either serum eicosapentaenic acid (EPA) or hair mercury of the habitants of Sakurajima, Iou and Takara Is. were measured. Furthermore, several methods of the quantitative analyzes of both total and methylmercury in sea water were examined for certifying the reproducibility of mercury contents and simplifing their procedures. Mercury contents of sea water at 26 stations from Kagoshima Bay were 0.1-3.2 ng/L, and lower than the values reported before. There was a significant correlation between mercury contents and the values of either temperature or pH of sea water and mercury contents of those in winter were higher than those in summer. Twenty six stations were classified into four areas, the entrance, the middle and the interior of the Bay, and the water around the Sakurajima area mercury contents of the samples from the last area and the interior were higher than either at the entrance or in the interior of the Bay only in winter. At Minamata-Fukuro Bay, mercury contents of sea water from the surface and depths in low and high tides were 1.2-5.0 and 1.2-1.7, and 1.8-5.4 and 1.6-4.2ng/L, respectivery. Mercury contents of a blue mussel, from Minamata-Fukuro Bay were 23-67ng/g, were significantly higher than those from Sakurajima, were 4-14 ng/g. The highest contents of either hair mercury (11.4 mu g/g) or serum EPA (90mg/L) were found in habitants of Sakurajima.
The effective methods of the quantitative analyzes of total and methylmercury from sea water, reported by Akagi and Nishimura (1991) were changed for the easier partly in the procedures of extraction and concentration of mercury compounds.
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