臺灣西南沿海烏腳病盛行地區自從裝設自來水後，烏腳病新病例已大為減少，但當地之肺癌死亡率，卻比臺灣地區一般人口為高。本研究之目的即在於瞭解烏腳病病人及其健康對照組的肺癌死亡率；並且探討砷暴露與肺癌的關係，以及當地居民罹患肺癌的危險因子。本研究採用世代追蹤研究法，進行研究世代之追蹤研究，其中有257名烏腳病病人，以及753名性別、年齡、居住鄉鎮匹配之健康對照者，追蹤時間為7年。結果發現本世代之肺癌標準化死亡比顯著高於臺灣地區一般人口；罹患烏腳病、砷皮膚癌者，其標準化死亡皆比其健康對照組偏高。與肺癌之相關達統計顯著意義的危險因子，包括年齡、吸菸習慣、砷相關疾病及飲水砷暴露。在經過多變項調整之後，砷暴露量與肺癌相對危險性仍呈顯著的劑量效應關係。砷暴露與吸菸習慣之間，對於肺癌的發生有交互作用存在。

　　　　　Since the tap water system was implemented in the endemic area of Blackfoot disease along the southwest coast of Taiwan Island, the incidence of newly developed cases of Blackfoot disease has been decreasing. However, the mortality from lung cancer in the endemic area remains higher than that of the general population in Taiwan. The purposes of this study includes:(1) To assess the lung cancer mortality of Blackfoot disease patients, and their age-sex-residence-matched healthy controls. (2) To explore the relationship between chronic arsenic exposure and lung cancer. (3) To evaluate the risk factors associated with lung cancer in this area. The subject was followed up in this long--term prospective study, including 257 blackfoot disease patients and 753 age-sex-residence-matched healthy contols. The analysis of mortality from lung cancer found that the lung cancer mortality of this cohort was significantly higher than that of the general population in Taiwan. The standardized mortality ratio (SMR) was 7.39 (95% confidence interval = 3.39-14.05) for blackfoot disease patients. Analysis of multiple risk factors as sociated with lung cancer were carried out using Cox's proportional hazards model. The risk factors significantly associated with lung cancer mortality included age, cigarette smoking, arsenic related disease, and ingested arsenic exposure. After adjusting for multiple risk factors, there was still a significant dose-response relationship between chronic arsenic exposure and lung cancer. There was also an interactive effect on lung cancer between arsenic exposure and cigarette smoking.