Cooking with biomass fuels like wood or dried vegetation is hazardous to lung health, according to research presented at the annual meeting of the Radiological Society of North America (RSNA). Advanced imaging with CT scans revealed that breathing the concentrated pollutants released by burning biomass can cause considerable lung damage.
About three billion people all over the world cook with biomass, and pollutants from cooking are linked to an estimated four million deaths a year.
Study co-author Abhilash Kizhakke Puliyakote is a postdoctoral researcher at the UC San Diego School of Medicine.
“It is important to detect, understand and reverse the early alterations that develop in response to chronic exposures to biomass fuel emissions,” said Dr. Puliyakote.
The research was focused on the impact of pollutants among 23 individuals who cook with either liquefied petroleum gas or wood biomass in Thanjavur, India. The experts measured the concentrations of pollutants in the homes, and tested the lung function of the participants.
The analysis showed that individuals who cooked with wood biomass were exposed to higher concentrations of pollutants and bacterial endotoxins compared to liquefied petroleum gas users. The participants who used wood in the kitchen were also found to have a much greater risk of air trapping, an abnormal retention of air in the lungs that 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 Dr. Puliyakote. “That part of the lung has impaired gas exchange.”
The researchers identified a smaller subset of biomass users who had very high levels of air trapping – even compared to other biomass users. Among one-third of the individuals classified in this group, more than half of the air they inhaled ended up trapped in their lungs.
“This increased sensitivity in a subgroup is also seen in other studies on tobacco smokers, and there may be a genetic basis that predisposes some individuals to be more susceptible to their environment,” said Dr. Puliyakote. She noted that the CT scans provided important details about the effects of biomass smoke on the lungs that were underestimated by conventional tests.
“The extent of damage from biomass fuels is not really well captured by traditional tests. 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.”
According to Dr. Puliyakote, the lack of emphysema in the study group suggests that exposure to biomass smoke is affecting the small airways in the lungs, but more research is needed to understand the disease process. “For people exposed to biomass smoke for any extended duration, it is critical to have a complete assessment of lung function by health care professionals to ensure that any potential injury can be resolved with appropriate interventions,” said Dr. Puliyakote.
The findings have important implications for exposure to biomass smoke from other sources, such as wildfires.
“In conjunction with the increasing prevalence of biomass smoke due to wildfires in the U.S., this study can provide valuable insights regarding similar study designs serving to understand what is certain to be a growing assault on lung health.”
The research was presented at RSNA 2020, the 106th Scientific Assembly and Annual Meeting.