Indoor burning coal air pollution and lung cancer--a case-control study in Fuzhou, China.

A case-control study on risk factors for lung cancer was carried out in Fuzhou, China. One-hundred and two newly-diagnosed primary lung cancer cases in urban Fuzhou (78 male and 24 female cases) were matched with 306 population-based controls. The primary histological types were adenocarcinomas (57 cases, 55.9%) and squamous cell carcinomas (39 cases, 38.2%). Controls were obtained from the general population by random, stratified sampling and consisted of noncancer cases matched for sex, ethnicity and age. Cases and controls were interviewed by trained professionals using a standardized questionnaire. Information was obtained on: smoking habits, living conditions, history of respiratory diseases, air pollution, and 40 other variables. The data were evaluated by conditional logistic regression analysis. The major risk factors for lung adenocarcinoma were: indoor air pollution from burning coal, chronic bronchitis, and high economic income. The risk factors for lung squamous cell carcinoma were: amount of cigarettes smoked per day, "deep inhalation", a history of exposure to environmental tobacco smoke (ETS) before 20 years of age, burning coal indoors, and high economic income. The results showed that the major risk factors for lung cancer in Fuzhou were: burning coal indoors, smoking, exposure to ETS before 20 years of age, chronic bronchitis, and high economic income. Cigarette smoking significantly increased the risk of lung squamous cell carcinoma, but had no significant association with the risk of lung adenocarcinoma. In summary, our research supports the hypothesis that smoking and indoor air pollution are the major risk factors for lung cancer in Fuzhou. Burning coal indoors and smoking were associated with lung cancer mortality in a major city in southern China.