| Summary: | 博士 === 國立臺灣大學 === 流行病學研究所 === 87 === In order to elucidate the occupational epidemiologic characteristic of health effects in dyestuff manufacturing workers, this thesis divided to three parts. (1) establishment of a cohort of dyestuff workers in Taiwan, (2) evaluation of health effects in dyestuff manufacturing workers, and (3) the association between susceptible factors and urothelial cell damage in dyestuff manufacturing workers. A cohort of workers from 15 dyestuff manufactories was established. A total of 14789 workers who had been employed before December 31,1998 were included in this cohort. 275 cohort members were identified as having died during 1987-1996 by comparing with Taiwan''s National Mortality Registry and 82 patients. Among them, six bladder cancer patients were under the jobs of middle or high exposure. We conclude that the whole cohort must be completed sequentially and the health surveillance must be performed for dyestuff workers. In order to understand the urothelial cell carcinoma in dye manufacturing workers and find an efficient marker to screen the early stage of bladder cancer, this study was made to take the workers in a benzidine-based dye manufactory. We used the flow cytometry to analysis the urothelial cell cycle. Cytological examination, bladder tumor antigen test and micronucleus assay were used to confirm the suspicious cases screened by cell cycle analysis. The results showed that the abnormality of DNA contents in urothelial cells from the occupational exposure were significant. And by multiple Poisson regression analysis, it is found that micronuclei formation is significantly higher in exposed group than in unexposed worker, and it is positively associated with age, work-years, smoking and drinking. In contrast, it is showed as a protective effect with tea. This study also was designed to investigate the influence of NAT2, GSTM1 and GSTT1 genotype on abnormal DNA ploidy of urothelial cells in dye manufacturing workers. Peripheral blood lymphocytes were collected from each subject and genotyped for NAT2 by PCR-RFLP methods and GST for PCR methods. Mmicronutrients in plasma, such as Vitamin A, Vitamin E, α-carotene, β-carotene and lycopene, were also determinated by HPLC and selenium was detected by GFAAS. This result supports that homozygous NAT2 mutant alleles and β-carotene in plasma modified the effect of occupational exposure which leads to the development DNA ploidy abnormality in urothelial cells among dye workers. Furthermore, it is shown that β-carotene might be more effective than NAT2 in preventing genetic effects on urothelial cells.
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