Exposure to wood smoke from home heating or cooking or from outdoor sources can increase a cigarette smoker’s risk of developing chronic obstructive pulmonary disease (COPD) up to fourfold.

As reported online ahead of print in American Journal of Respiratory and Critical Care Medicine, a team led by Yohannes Tesfaigzi, PhD, analyzed self-reported wood-smoke exposure, post-bronchodilator spirometry results, and COPD outcomes among 1,827 persons aged 40 to 75 years in the predominantly female Lovelace Smokers’ Cohort. Researchers learned that wood-smoke exposure was independently associated with reduced lung function—lower percent predicted FEV1 and higher prevalence of airflow obstruction and chronic bronchitis. This relationship was strongest in current cigarette smokers, non-Hispanic whites, and men. Furthermore, wood-smoke exposure was associated with specific COPD outcomes and related pulmonary problems in people with certain changes in genes known to be associated with lung cancer.

“These studies identify a novel link between wood smoke exposure and gene promoter methylation that synergistically increases the risk for reduced lung function in cigarette smokers,” the study’s authors noted.