Improvement in household stoves and risk of chronic obstructive pulmonary disease in Xuanwei, China: Retrospective cohort study

Abstract

Objective To test whether improvement in household coal stoves affected the incidence of chronic obstructive pulmonary disease (COPD) in Xuanwei County, China. Design Retrospective cohort study (follow-up 1976-92) comparing incidence of COPD between groups with and without chimneys. Participants 20 453 people born into homes with unvented coal stoves;16 606 (81.2%) subsequently changed to stoves with chimneys. Intervention Installation of a chimney in households in which unvented stoves had been used previously. Results Installation of a chimney was associated with distinct reduction in the incidence of COPD. Compared with people who did not have chimneys, the Cox-modelled risk ratio (relative risk) was 0.58 (95% confidence interval 0.49 to 0.70, P < 0.001) in men and 0.75 (0.62 to 0.92, P = 0.005) in women. Modelled risk ratios were robust to different Cox model specifications. Relative risks decreased with time since stove improvement. In both sexes, the reduction in risk became unequivocal about 10 years after stove improvement. Conclusions In Xuanwei, incidence of COPD decreased markedly after household coal stoves were improved.

Indoor air pollution from solid fuel use, chronic lung diseases and lung cancer in Harbin, Northeast China

“…These associations may be explained by the fact that COPD causes a long-standing inflammatory reaction in the bronchi and inflammation itself may play a role in the development of lung cancer (Balkwill and Mantovani, 2001;Littman et al, 2004;Mantovani, 2007). As several studies found that the mixture of pollutants from combustion of coal and biomass were associated with lung cancer as well as several other lung diseases, including COPD and PT (Smith et al, 2004;Chapman et al, 2005), all the ORs for lung cancer according to a history of lung diseases were also adjusted for exposure to IAP index, and the results did not substantially change, supporting an independent role of COPD and PT in lung carcinogenesis. Furthermore, the combination of exposure to IAP and COPD/TP led to an approximately sixfold increased cancer risk.…”

Emphysema in the Nonsmoker

“…71 Chronic exposure has been linked with the development of chronic obstructive pulmonary disease 73 and emphysema. 74 …”