Wood-Fired Cooking a Cause of Lung Illness in Developing World
People who cook with wood instead of other fuels may be at risk of lung damage because of the pollutants and bacterial toxins they're breathing, a small study suggests.
Researchers studied the impact of cookstove pollutants on 23 people in Thanjavur, India, who use liquefied petroleum gas or wood biomass (wood, crop waste or wood brush) to cook.
They measured concentrations of pollutants in participants' homes and used tests, including spirometry and advanced CT scans, to study individuals' lung function. For example, they acquired one scan when a person inhaled and another after he or she exhaled, then measured the difference to see how the lungs were functioning.
The researchers found that people who cooked with wood had greater exposure to pollutants and bacterial endotoxins and a higher level of air trapping in their lungs, which is associated with lung diseases.
"Air trapping happens when a part of the lung is unable to efficiently exchange air with the environment, so the next time you breathe in, you're not getting enough oxygen into that region and eliminating carbon dioxide," said study co-author Abhilash Kizhakke Puliyakote, a postdoctoral researcher at the University of California, San Diego School of Medicine. "That part of the lung has impaired gas exchange."
A smaller subset of those who cooked with wood had very high levels of air trapping and other lung problems. In about a third, more than 50% of the air they inhaled was trapped in their lungs. There may be a genetic predisposition for some individuals to be more susceptible to their environment, Kizhakke Puliyakote said.
"The extent of damage from biomass fuels is not really well-captured by traditional tests," he said. "You need more advanced, sensitive techniques like CT imaging. The key advantage to using imaging is that it's so sensitive that you can detect subtle, regional changes before they progress to full-blown disease, and you can follow disease progression over short periods of time."
The findings are scheduled for presentation at the annual meeting of the Radiological Society of North America, being held online Nov. 29-Dec. 5.
Worldwide, about 3 billion people cook with wood. This type of burning is a major contributor to the estimated 4 million deaths annually from air pollution-related illness.
Public health initiatives have tried to help people make the switch to cleaner-burning liquefied petroleum gas.
"It is important to detect, understand and reverse the early alterations that develop in response to chronic exposures to biomass fuel emissions," Kizhakke Puliyakote said in a meeting news release.
The research was led by Eric Hoffman, a professor of radiology at the University of Iowa in Iowa City, in collaboration with Periyar Maniammai Institute of Science and Technology in Vallam, India.
The lack of emphysema in study participants suggests that wood biomass affects the small airways, Kizhakke Puliyakote said. The lungs may have injury and inflammation that goes undetected and unresolved even in those who don't have obvious breathing difficulties.
While the study focused on cooking with wood, the findings have important implications for exposure to wood-burning smoke from other sources, including U.S. wildfires.
Research presented at meetings is typically considered preliminary until published in a peer-reviewed journal.
The World Health Organization offers a fact sheet on household air pollution.
SOURCE: Radiological Society of North America, news release, Nov. 25, 2020