Wood burners should have health warning, scientists say

Pollution caused is linked to lung cancer, strokes, Parkinson’s disease and dementia

The stoves can triple harmful particulate pollution inside homes (AFP via Getty Images)

Wood-burning stoves should be sold with a health warning because of the potentially lethal pollution particles they emit into homes, scientists have concluded.

The burners can triple the number of damaging particles in a room, and should not be used around children or the elderly people, researchers say.

The pollution they cause is understood to be linked to lung cancer, bronchitis and other respiratory infections, strokes, Parkinson’s disease and dementia.

Opening the stove door to add more wood floods a room with the damaging particles, according to the study, which was carried out in 20 homes in Sheffield at the start of the year.  

The wood-burners used were all certified by the government as “smoke-exempt”, which means they were designed to limit the smoke produced from burning.

When wood is burnt, it releases harmful pollutants, including tiny particles known as PM2.5, which are easily inhaled. Of all pollutants, this particulate matter has the greatest effect on health.

The scientists analysed data collected every few minutes from monitors in the study participants’ homes. While the stoves were lit, the harmful particles level was three times higher than when they were out, and average particle levels rose to between 27 and 195mcg per cubic metre of air. The World Health Organisation limit is 25mcg over 24 hours.

“As these particulates can move into every organ in the body, the illnesses that are associated with their presence range from lung cancer, bronchitis, and other respiratory infections, through to strokes, dementia, and Parkinson’s disease,” the study said.

“Effects such as these are particularly pronounced for children, pregnancies, and the elderly.”

People who put in more wood twice or more in an evening were exposed to pollution spikes two to four times higher than those who refuel once or not at all, said the researchers.

The Department for Environment, Food and Rural Affairs (Defra) estimates suggest that one in 12 UK homes is using a stove of this kind and, in doing so, causing 38 per cent of the nation’s PM2.5 emissions.

Figures suggest wood stoves are growing in popularity, with up to 200,000 sold every year.  

“Our findings are a cause for concern,” Rohit Chakraborty, of the University of Sheffield, who led the study, told The Guardian.  

“It is recommended that people living with those particularly susceptible to air pollution, such as children, the elderly or vulnerable, avoid using wood-burning stoves. If people want to use them, we recommend minimising the time the stove is open during lighting or refuelling.”

The study, published in the journal Atmosphere, concluded: “The particulate matter that is released into the home is not an aberration from normal use, but results directly from it. This is because real-world operation cannot occur without opening the stove door.  

“It may be that with regulatory encouragement stove designs can be modified in a way that limits such instances. In the meantime, or in the event that appropriate modification cannot be achieved, it is also recommended that new residential stoves be accompanied by a health warning at the point of sale in order to indicate the normative health risks posed to users.”

Gary Fuller, of the London Air Quality Network at King’s College London, previously told the Evening Standard: “Globally, breathing PM2.5 is one of the largest risk factors for an early death.”

A Defra spokesperson said: “Air pollution has reduced significantly in recent years, with emissions of fine particulate matter falling 9 per cent in the last decade. But we know there is more to do, and domestic burning is a major contributor.”