Exposure to coal and/or biomass smoke is a major risk
factor for developing COPD in non-smokers in China.
People exposed to biomass smoke have an odds ratio of 2.44 (95% CI 1.9 –3.3) for developing COPD relative to those not exposed to biomass smoke.34 In our study, 38.7% of subjects were exposed to biomass smoke. Among nonsmokers, 67.5% (1,395/2,067) of subjects were exposed to biomass smoke. After a 4-y health management program, the rate of exposure to coal and/or biomass smoke was reduced by 14.0% in the management group compared with the control group. This result shows that the health management program was effective in reducing exposure to biomass smoke.