| Summary: | 碩士 === 國立成功大學 === 環境醫學研究所 === 94 === Owing to the unique physical and chemical properties of mercury, it has been exploited for a variety of uses in industry, agriculture, and supplies. Fish consumption was the main pathway for human exposure to mercury. An-Shun chlor-alkali plant, located in western Tainan, had operated for tens of years and lots of sludge contained mercury produced from the process was dumped in/around the factory. According to previous environmental surveillance, the sediment of seawater reservoir in the plant were highly contaminated with mercury. Local residents used to catch aquatics from the reservoir for consumption. The measured data provided evidence that the residents had high exposure risk of mercury. The aim of this study was to investigate the mercury distribution and biota-sediment availability factors(BSAFs) between sediment and aquatics in the seawater reservoir. Furthermore, to discuss the relationship between seafood consumption, blood total mercury, and results of health examination, respectively. The mean mercury concentration of sediment samples was 25.5±23.6 mg/kg(d.w.). Forty-four percent of sediment samples exceeded the limit of soil total mercury. Only one crab of all aquatic samples which total mercury level exceeded the protective standard of Taiwan, and the average mercury concentration of aquatic samples was slightly higher than those from twelve major rivers in Taiwan. Therefore, compared with former data, the BSAFs calculated in this study was considerably low. 494 residents living near the seawater reservoir were recruited in this study, the average of their blood total mercury was 15.4±10.3 μg/L. There was 21.7% of the subjects whose blood total mercury were higher than general population(20 μg/L). The subjects were grouped by 75 percentile of total mercury levels. Their blood total mercury was significantly correlated with age(p=0.0172) and seafood consumption (p=0.0505). Male ratio of high level group was significantly higher than low level group(p<0.0001). But the male consumed more seafood than the female in this study(p=0.0009). Creatinine and BUN concentrations of high blood mercury level group was higher than low level group, but their blood cell number and Hgb was lower, comparatively. Other items of health examination were no significant differences between two groups.
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