Adding a log to a glowing fireplace on a cold winter night often feels comforting and harmless. However, new research from Northwestern University shows that burning wood inside homes plays a much larger role in winter air pollution across teh United States than many people realize.
The study found that even though only 2% of U.S. households use wood as their main source of heat, residential wood burning is responsible for more than one-fifth of Americans’ winter exposure to outdoor fine particulate matter (PM2.5).
These microscopic particles are small enough to travel deep into the lungs and enter the bloodstream. Long-term exposure has been linked to serious health problems, including heart disease, lung disease, and premature death.Based on their analysis, the researchers estimate that pollution from residential wood burning is associated with about 8,600 premature deaths each year.
Urban communities face the greatest risks
One of the study’s most unexpected findings is where the greatest harm occurs. People living in cities are affected more than those in rural areas. The health impacts also fall disproportionately on people of color, who tend to burn less wood but experience higher exposure levels and greater health risks from wood smoke. The researchers point to higher baseline mortality rates and the lasting effects of past discriminatory policies as key factors behind this disparity.
The findings suggest that reducing wood burning inside homes could considerably lower outdoor air pollution, leading to major public health benefits and potentially saving thousands of lives.
The study was published on Jan. 23 in the journal Science Advances.
“Long-term exposure to fine particulate matter is associated with an increased risk of cardiovascular diseases,” said Northwestern’s Kyan Shlipak, who led the study. “Studies have consistently shown that this exposure leads to a higher risk of death. Our study suggests that one way to substantially reduce this pollution is to reduce residential wood burning. Using choice appliances to heat homes instead of burning wood would have a big impact on fine particulate matter in the air.”
Why home wood burning is frequently enough overlooked
Wildfire smoke often dominates public attention, but pollution from everyday home heating rarely receives the same scrutiny.
“We frequently hear about the negative health impacts of wildfire smoke, but we don’t frequently enough consider the consequences of burning wood for heat in our homes,” said Northwestern’s Daniel Horton, the study’s senior author. “Since only a small number of homes rely on wood burning for heat, helping homes switch to cleaner or non-burning heat sources could lead to significant improvements in air quality.”
horton is an associate professor of Earth, environmental and planetary sciences at Northwestern’s Weinberg College of Arts and sciences, where he directs the Climate Change Research Group (CCRG). shlipak is an undergraduate in mechanical engineering at Northwestern’s McCormick School of Engineering.