A recent study conducted in the United States has found a significant link between indoor wood burning and an increased risk of lung cancer in women. According to the research, women who use indoor wood stoves or fireplaces face a 43% higher risk of developing lung cancer compared to those who do not use wood heating.
Lung cancer is a prevalent and severe health concern, with varying rates of diagnosis worldwide. In the UK, one in 13 men and one in 15 women born after 1960 are expected to be diagnosed with lung cancer during their lifetimes, while in the U.S., the statistics are one in 16 for men and one in 17 for women.
The study, known as the Sister Study, monitored the health of 50,000 U.S. women with sisters diagnosed with breast cancer. Dr. Suril Mehta, from the U.S. National Institute of Environmental Health Sciences and the lead author of the study, explained, “Lung cancer is the leading cause of cancer-related death among U.S. women, accounting for roughly one in five cancer-related deaths in the U.S.”
The research revealed that the frequency of indoor wood heating usage correlated with the level of risk. Those who used wood burners for more than 30 days a year faced a significantly higher risk, with a 68% increase in lung cancer risk compared to non-users.
Globally, tobacco smoking is the most significant risk factor for lung cancer, but this study shows that it is not the only one. After tracking the health of the participants for an average of 11 years, the study found that there were clear differences in lung cancer risk between those who used indoor wood heating and those who did not, regardless of their smoking history.
In the UK, only 4% of homes using solid fuel rely on it as their primary heating source. Similarly, the Sister Study participants primarily used gas or electricity for heating, with wood heating being a secondary or tertiary source.
Dr. Mehta emphasized, “Our study provides evidence that even occasional indoor wood burning from stoves and fireplaces can contribute to lung cancer in populations where indoor wood burning is not the predominant fuel source for cooking or heating inside the home.”
Professor Fay Johnston from the Menzies Institute for Medical Research, Tasmania, who was not involved in the study, stated, “The new results from the Sister Study provide strong evidence of the risk of living in homes heated by wood combustion. Even relatively low usage was associated with an increased risk of lung cancer,” and urged policymakers to prioritize interventions to reduce exposure to wood heater smoke in homes and neighborhoods.
This research adds to a growing body of evidence indicating the cancer risk associated with wood smoke. In 2006, the International Agency for Research on Cancer classified wood smoke as probably carcinogenic to humans. Another international study from 2010 found an increased risk of lung cancer in people using wood and coal heating.
Dr. Mehta explained, “Wood smoke, from using wood-burning appliances indoors, may contain substances such as benzene, 1,3-butadiene, polycyclic aromatic hydrocarbons, and other hazardous air pollutants, which are known or suspected to cause lung cancer.”
While the study also noted a slight increase in lung cancer risk associated with gas or propane heating in stoves and fireplaces, this risk was considerably smaller than that associated with wood burning. A previous report from the Sister Study also identified air pollution from indoor wood burning as a widespread and potentially modifiable risk factor for breast cancer.
