A new study out of Guangzhou, China suggest that people who burn wood or other “biofuels” for heat or cooking may have a heightened risk of emphysema and related lung conditions.
Until now, the role of smoke from biomass fuels – which refer to biological materials including wood, crops and animal dung that are burned for energy – has been unclear. However, the Chinese study’s findings strengthen the evidence that exposure to biomass smoke is a risk factor for COPD.
In an analysis of 15 international studies, researchers found that people exposed to this smoke in their homes generally had a greater risk of chronic obstructive pulmonary disease (COPD) than those who used other sources for cooking and heating.
The study, published in Chest, combined the results of studies out of Asia, South America, Mexico and Spain involving a total of 3,719 adults with COPD and 39,000 healthy individuals who were surveyed regarding past exposure to biomass smoke at home. Though studies cannot prove cause-and-effect, a relationship between biomass smoke exposure and risk of COPD was found.
Researchers found that participants who reported exposure to biomass smoke at home were more than twice as likely to have COPD as those with no exposure. These risks were consistent in men and women across geographical regions, and seemed to affect COPD risk independent of cigarette smoking. However, smokers exposed to biomass smoke had more than four-fold the risk of COPD than non-smokers who did not burn biomass fuels at home.
With biomass fuels thought to be used for cooking and heating in half of homes worldwide, particularly in rural areas of developing countries, the research team concludes that “the public health consequences of biomass smoke with regard to COPD (are) important,” and reducing exposure might help prevent some cases of lung diseases. Click here to access the full story on Medline Plus
New research from the National Institute for Occupational Safety and Health (NIOSH) indicates that exposure to coal dust is directly linked to the severity of emphysema in smokers and nonsmokers alike. These findings highlight a health problem related to a growing number of individuals, as coal production has nearly doubled worldwide in the past 25 years.
Researchers at NIOSH compared lung autopsy results from 722 individuals, including 616 coal miners and 106 non-miners from West Virginia and Vermont between 1957 and 1978. Exposure to coal dust was estimated using work history data and job-specific dust exposure estimates. Sections of the lungs were then examined to determine the presence and extent of emphysema, which was graded for type and severity. Lung tissue from a smaller subset of the study group was also analyzed for dust content.
Researchers found that cumulative exposure to respirable coal mine dust to be a significant predictor of emphysema severity. Cigarette smoking, age at death and race were all accounted for separately, and emphysema in miners was found to be significantly more severe than non-miners in both smokers and non-smokers. However, emphysema was also more severe among smokers than non-smokers in miners and non-miners, demonstrating that cigarette smoking and dust exposure have similar effects on emphysema severity.
It was also found that higher concentrations of coal dust in the lungs negatively affected the severity of emphysema.
Researchers caution that the data was collected from individuals who worked in the mines before enforcement of the federal standard limiting legal coal dust concentrations in 1972. This removes any immediate relevance to current occupational safety standards.
Nonetheless, researchers believe that, even at the current federal standard, a working lifetime of exposure to coal dust will produce a cumulative exposure similar to the levels found in the autopsied miners. Coal dust exposure is now generally accepted as a cause of COPD, but this study will improve the recognition of dust-induced COPD, its relationship to cigarette smoking, and could enhance prevention efforts, diagnosis and medical management of occupational dust-related lung diseases. Click here to read the full story on ScienceDaily.