Washington: If you are a smoker and regularly exposed to wood smoke then you are four times higher at risk of chronic obstructive pulmonary disease (COPD) and other pulmonary problems, say scientists.
The exposure to wood smoke through home heating and cooking or through ambient neighborhood pollution may result inepigenetic changes in the DNA that further increase their risk of COPD and related pulmonary problems.
"When cigarette smokers are exposed to wood smoke their risk of having reduced lung function increases," explained Yohannes Tesfaigzi of Lovelace Respiratory Research Institute.
"Cigarette smokers who have both changes in sputum DNA and are exposed to wood smoke have a synergistically increased risk of having reduced lung function and other indicators of COPD such as chronic mucous hypersecretion," he added.
Tesfaigzi and colleagues administered questionnaires to more than 1800 current and former smokers between 40 and 75 years old.
They found that wood smoke exposure was significantly and independently associated with an increased risk of respiratory disease, especially among current smokers, non-Hispanic whites and men.
Furthermore, wood smoke exposure was associated with specific COPD outcomes in people who had aberrantly methylated p16 or GATA4 genes, and both factors together increased the risk more than the additive of the two risk factors together.
"Because exposure to wood smoke appears to increase the risk of reducing lung function, cigarette smokers should try to avoid heating their homes or cooking with wood stoves and try to avoid environments where wood smoke is likely," said Tesfaigzi.
"Because the same gene changes were associated with increased risk for lung cancer one would assume that wood smoke exposure also increases the risk of developing lung cancer,” he added.
Based on these findings, the researchers established an animal model that will be able to further test whether both wood and tobacco smoke exposure cause more damage to the lung than either one of the exposures alone.
"We observed increased inflammatory response in mice that were exposed to both cigarette smoke and low concentrations of wood smoke compared to those exposed to cigarette smoke only," said Tesfaigzi.
The research was published on the American Journal of Respiratory and Critical Care Medicine.