Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for household heating and cooking. This review focuses on several decades of research carried out in Xuanwei County, Yunnan Province, where household coal use is a major source of household air pollution and where studies have linked household air pollution exposure to high rates of lung cancer. We conducted a series of case-control and cohort studies in Xuanwei to characterize the lung cancer risk in this population and the factors associated with it. We found lung cancer risk to vary substantially between different coal types, with a higher risk associated with smoky (i.e., bituminous) coal use compared to smokeless (i.e., anthracite) coal use. The installation of a chimney in homes resulted in a substantial reduction in lung cancer incidence and mortality. Overall, our research underscores the need among existing coal users to improve ventilation, use the least toxic fuel, and eventually move toward the use of cleaner fuels, such as gas and electricity.
Air Pollution, Indoor ; adverse effects ; China ; Coal ; adverse effects ; classification ; Cohort Studies ; Cooking ; Fossil Fuels ; Heating ; Humans ; Incidence ; Lung Neoplasms ; etiology ; mortality ; Risk Factors ; Smoke ; adverse effects ; Smoking

China ; epidemiology ; Cohort Studies ; Female ; Humans ; Lung Neoplasms ; epidemiology ; mortality ; Male ; Metallurgy ; Nickel ; toxicity ; Occupational Exposure ; adverse effects ; Pulmonary Heart Disease ; epidemiology ; mortality ; Retrospective Studies ; Silicosis ; epidemiology ; mortality

OBJECTIVETo study the association between metal exposure and risk of diabetes and prediabetes among Chinese workers exposed to metals.

METHODSWe used data obtained from the baseline survey of the Jinchang Cohort Study of workers in Jinchang Industry, the largest nickel production company in China. A total of 42,122 workers ⋝20 years of age were included in the study. A standardized, structured questionnaire was used to collect epidemiological information. Physical examinations and laboratory tests were conducted to evaluate the health status of the participants and to measure various biomarkers including blood sugar, lipids, and urinary metal concentrations. Logistic regression was used to study the association between occupational groups categorized according to the measured metal levels (office workers, low-level; mining/production workers, mid-level; and smelting/refining workers, high-level) and risk of diabetes and prediabetes.

RESULTSThe overall prevalence of diabetes and prediabetes was 7.5% and 16.8%, respectively. The adjusted odds ratios for diabetes among mining/production workers and smelting/refining workers compared to office workers were 1.5 (95% CI: 1.3, 1.7) and 3.8 (95% CI: 3.4, 4.3), respectively. No association was observed between these occupational groups and prediabetes in this study.

CONCLUSIONOccupations associated with higher levels of metal exposure were associated with an increased risk of diabetes in this cohort. More studies are needed to confirm this observed association.

Adult ; China ; epidemiology ; Cohort Studies ; Female ; Humans ; Male ; Metals, Heavy ; toxicity ; urine ; Middle Aged ; Occupational Exposure ; adverse effects ; Prediabetic State ; chemically induced ; epidemiology