| Summary: | 碩士 === 國立臺灣大學 === 流行病學研究所 === 87 === The objectives of this project are to conduct a MOR (mortality odds ratio) study and determine if there is increased cancer frequency among residents who have lived in a community where the groundwater was contaminated with wastes of chlorinated organic solvents disposed by an electronic manufacturing factory. Death certificate data of two villages at Taoyuan were collected for the period 1966-1997. Cancers at different organ systems were considered as the diseases of interest, while cardiovascular-cerebrovascular (CV-CB) diseases as the reference disease. After studying the groundwater hydrogeology, residents were classified as exposed and non-exposed groups according to villages where they once lived were either downstream or upstream of the contaminated factory. MORs were calculated for various kinds of cancers after stratified by sex, age, and latency period. Multiple logistic regression adjusting for age and period were performed to evaluate the exposure effect.
The results showed that there was no increase of MOR for all sites of cancers during the period 1966-1975. The MORs for stomach and liver cancers during 1976-1997 for men aged 50-69 were significantly increased with ORs (95% confidence interval) of 4.28 (1.29, 16.40) and 2.89 (1.06, 8.19). After adjustment for age and period, MORs for stomach and liver cancer in men were 2.02 (0.90, 4.52) and 2.27 (1.09, 4.75). Gas chromatography showed the contaminated compounds and their individual concentrations in wells of downstream village were tetrachloroethylene (<0.5~4800μg/L), trichloroethylene (<0.5~930μg/L), vinyl chloride (<0.5~25μg/L), 1,1-dichloroethylene (<0.5~1418μg/L), and 1,1,1-trichloroethane (<0.5~1121μg/L). Since there was a temporal trend i.e., the factory established in early 1970''s, and age, sex were under control in the analysis, we tentatively concluded that the causal association can not be ruled out.
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