Household stove improvement and risk of lung cancer in Xuanwei, China

Abstract

Background: Lung cancer rates in rural Xuanwei County, Yunnan Province, are among the highest in China. Residents traditionally burned “smoky ” coal in unvented indoor firepits that generated very high levels of air pollution. Since the 1970s, most residents have changed from firepits to stoves with chimneys. This study assessed whether lung can-cer incidence decreased after this stove improvement. Meth-ods: A cohort of 21 232 farmers, born from 1917 through 1951, was followed retrospectively from 1976 through 1992. All subjects were users of smoky coal who had been born into homes with unvented firepits. During their lifetime, 17 184 subjects (80.9%) changed permanently to stoves with chimneys. A hospital record search detected 1384 cases of lung cancer (6.5%) during follow-up. Associations of stove improvement with lung cancer incidence were analyzed wit