| Summary: | 碩士 === 中國醫藥學院 === 環境醫學研究所 === 87 === The main purpose of this study is to investigate the relationship between cancer incidence and the selected environmental factors. Besides we discussed the total cancer incidence, we also selected three kinds of the most common cancer incidence in both genders such as hepatoma, lung cancer and colorectal cancer, and three kinds of potentially environmental related cancers such as urinary organs cancer, blood system cancer and leukemia , to further study and compare. For the environmental factors, we included the distributions of administrative district, geographic pattern, degree of urbanization, industrial region, location of electric power station and location of incinerator. The basic unit for the above environmental factors is county and that was also used to link the data with the other data such as cancer data and population data. We mainly used the data of cancer incidence registered by Department of Health and population data registered by Minister of Internal from 1987 to 1996. The standardized incidence ratio was used to analyze the relative risk of cancers among different areas and the variations among administrative districts are displayed in maps. Homogeneity analysis by Chi-square test and proportional odds model were used to analyze the relationship between cancer incidence and environmental factors. And we also tried to establish a geographic information system for the long-term monitoring of the influences of insidious pollutant sources to cancer incidence.
The results show that the incidence of all cancers is higher in northern and middle regions of Taiwan. The occurrences of carcinoma of kidney and urinary organs as well as hepatoma cluster in southern west coast; the lung cancer clusters in northern and southern-west coast; the colorectal cancer forms another pattern of cluster in the urban of middle and northern regions. The cancer of hemopoietic and reticulo-endothelial system and leukemia, both are related to blood, reveal higher risk in areas with higher sea-level. Considering the other environmental factors, for geographic areas, comparing with the plain areas, the odds ratio of cancer incidence in the mountain areas is 0.53（P>0.05）in male and 0.26（P<0.001）in female. In off-shore islands it is 0.06（P<0.01）in male and 0.01（P<0.01）in female. The risk is also higher in the highly urbanized regions than low urbanized ones. Comparing with the low urbanized regions, the odds ratio in highly urbanized regions is 5.67（P<0.001）in male and 14.18（P<0.001）in female. Most of people living near power stations receive higher risk than those living right at the sites of power stations, and both are higher than the areas not near the power station. Comparing with the areas not near the power station, the odds ratio in the regions near power stations is 3.24（P<0.001）in male and 3.54（P<0.001）in female. Comparing with the regions without incinerator, the regions with incinerator being built has showed higher risk, with odds ration of 4.68（P<0.001）in male and 3.7（P<0.01）in female, which can not be attributed to the influence of setting incinerator considering the effect of time.
Key words : cancer incidence, environmental factors, Geographic Information System(GIS)
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