Wood-burning stoves hurt lungs like cigarettes: study

By Stephen Beech

Wood-burning stoves can damage lungs in a "similar way" to cigarette smoke, warns new research.

Using a trendy indoor wood burner at home can lead to a decline in lung function by causing inflammation, say scientists.

The use of solid fuel for domestic heating has soared in the UK and Europe - particularly among wealthy families - due to the marketing of wood as renewable energy and high fossil fuel prices.

In the UK, the proportion of harmful PM2.5 air pollution - known as fine particulate matter - caused by domestic solid fuel is now 20% of the total, compared with 4% for road vehicle exhaust emissions.

Annual emissions, specifically from domestic wood burning, almost doubled from 3,200 tonnes in 2009 to 6,000 tonnes in 2023.

Building on a previous study that mapped the use of solid fuel-burning stoves across the UK, researchers used data from the English Longitudinal Study of Aging (ELSA) to look at the connection between self-reported solid fuel use at home in England and lung function decline.

The team assessed patients’ lung function according to a measure called FEV1, which quantifies the amount of air a person can forcefully exhale in the first second of a breath.

Lower FEV1 values are associated with increased risk of respiratory complications and poorer health, making it a key marker for monitoring diseases such as asthma and chronic obstructive pulmonary disease (COPD).

Study leader Dr. Laura Horsfall said: “We know wood burning at home emits harmful air pollution both indoors and outdoors, including known carcinogens.

"Despite this, air pollution from this source has approximately doubled in the UK since 2009 as more people install and use wood stoves.

"However, the link with health outcomes in high-income countries is not well understood and residential areas with high emissions are hard to identify using existing air quality monitoring networks."

Dr. Horsfall, principal research fellow at the Institute of Health Informatics at University College London (UCL), explained that studying health impacts is "challenging" because wood-burning households tend to be wealthier and healthier overall.

She said: “We found that people using solid fuel had lower rates of smoking and lung disease, which can mask the true effects of solid fuel exposure.

“However, using repeated lung function measurements over an eight-year period, we found that lung function declined faster among solid fuel users compared to non-users, even after adjusting for socio-economic and housing factors.

"This suggests an important link between solid fuel use and respiratory decline, despite the healthier baseline of the exposed group."

Dr. Horsfall added: “Our study suggests that high levels of particulate matter from stoves damage respiratory tissues, causing inflammation in a similar way to cigarette smoke."

Dr. Horsfall and her team now plan to investigate whether people living in or near areas with a high concentration of wood stoves - such as the wealthier parts of London - also show increased rates of respiratory issues, such as inhaler prescriptions and hospital visits for lung conditions.

She is due to present the findings at the European Respiratory Society (ERS) Congress in Amsterdam, Holland.

The ERS says the study suggests that wood burners should be considered a "potential environmental risk factor" in the future.

Professor Ane Johannessen, head of the ERS expert group on epidemiology and environment, said: "In Europe, we are seeing a growing trend for using wood-burning stoves at home.

"Research in other parts of the world, where traditional wood burning is used in the home, has shown that this is harmful and causes asthma, COPD and lung cancer.

"These findings suggest that wood-burners used in European homes may have similar effects and should be considered a potential environmental risk factor when assessing respiratory health, especially in patients with unexplained lung function decline or chronic respiratory symptoms.

"Although new eco-design European wood-burners are generally considered cleaner and safer than more traditional wood stoves, many European homes still employ older wood-burners, and even the newer stoves may not be entirely risk-free."

Johannessen, of the University of Bergen in Norway, added: "This study underscores the need for clearer public health guidance and regulation around domestic wood burning.

"People should be aware that these stoves could be harming them and their families, and doctors should be asking their patients about whether they are using stoves at home.”