A woman who monitored indoor air pollution levels after using a wood-burner has revealed the concerning results – and says it has changed how her family will use it in the future.
Concerns have been growing around the trendy stoves after a study last year linked them to thousands of deaths every year in Britain. They were subsequently hit with cigarette-style health warnings in January.
The burners – popular in urban areas outside major cities – work by scorching dry firewood in a sealed box before a blower fan distributes the hot air around the room.
But major research has found this to be a source of air pollution known as particulate matter (PM) – linked to dementia, heart and lung disease.
A report last October by climate charity Global Action Plan and Hertfordshire County Council connected the pollution to an average of more than 3,700 cases of diabetes and nearly 1,500 cases of asthma in the country each year.
Just months later, the government unveiled proposals in January for the burners to to carry a label outlining the harms pollution can cause including lung cancer.
In recent months, there has been a shift towards ‘healthier’ ceramic stoves, but many are refusing to give up their prized wood-burners.
Hannah Healey’s parents, who live in rural Cornwall, are among those who have kept their stove, typically using it during the winter months to keep cosy.
A woman who monitored pollution levels in her parents’ home after using her wood-burner has revealed the concerning results (stock image)
But as a health investigations writer for Which?, Ms Healey is aware of the risks wood-burners can pose.
With that in mind, she set out to track just how many potentially harmful particles her parents are regularly being exposed to.
To investigate, Ms Healey used an air quality monitor in the living room for five days, measuring levels of PM2.5 and PM10 – pollution particles in the air – in micrograms per cubic metre (µg/m3).
For example, a result of 1µg/m3 would mean that every one cubic metre of air contains one microgram of PM.
PM2.5 has been linked to a range of serious health problems, including stroke, cardiovascular disease, lung cancer and chronic respiratory infections.
Short-term effects can also include coughing, breathing difficulties, headaches, infections of the eyes, nose and throat, as well as skin irritation, allergies and acute lower respiratory infections.
After analysing the air in her parents’ house for five days, Ms Healey found that PM2.5 levels were far higher when the wood burner was in use compared to when it was not.
During burning periods, PM2.5 readings ranged from 4.91µg/m3 on day one to 11.94µg/m3 on day five. It exceeded 11µg/m3 on three of the five days.
By contrast, pollution levels were below 1µg/m3 on four out of five days when the wood burner was not in use, hitting a high of 1.74µg/m3 on day five.
She also found air pollution spiked sharply after the stove was lit.
On one evening, levels of PM2.5 were between 0µg/m3 and 1µg/m3 before she used the wood burner.
After lighting it at 7.10pm levels of the pollutant averaged at 16.24µg/m3, before tapering down to 10.07µg/m3 between 9pm and 10pm.
The highest pollution level recorded during Ms Healey’s study was 24.46µg/m3.
Official guidance by the World Health Organisation states that the recommended limit for average PM2.5 exposure over a 24-hour period is 15µg/m3, meaning Ms Healey’s average results sat below that threshold.
However, Professor James Allan, professor of air pollution measurement at the University of Manchester warned that ‘even studies of relatively low levels of air pollution have found adverse health effects.’
He told Which?: ‘In addition, it seems that particulate matter from wood burning is a particularly harmful form of pollutant.’
Dr James Heydon, associate professor at the school of sociology and social policy at the University of Nottingham, added: ‘Research suggests that PM2.5 is especially damaging to your health because it can enter your bloodstream, which means it can cause inflammatory responses throughout the body.’
Ms Healey concluded that while she remains unsure exactly how harmful her parents’ wood-burner is, it has made them reconsider how often they use it.
She said: ‘We’ve decided we won’t continue to use it every single night, as we don’t feel it’s worth the potential health risks of even low levels of daily PM exposure.
‘We won’t stop using it altogether, but will consider it to be a treat for special occasions rather than something to do every day.’
Her findings come just months after tighter restrictions and guidelines were introduced for wood-burners in Britain.
As well as announcing that stoves would carry warning labels, ministers also proposed cutting the limit on smoke emitted from wood-burners by 80 per cent, to one gram per hour.
However, the long-awaited measure would apply only to new wood burners, many of which already meet the stricter limits.
Emma Hardy, the air quality minister, said: ‘Dirty air robs people of their health and costs our NHS millions each year to treat lung conditions and asthma.
‘We are determined to clean up our air. By limiting emission levels and introducing new labels as outlined in our consultation, families will be able to make better, healthier choices when heating their homes.’
The restrictions are predicted to cut annual toxic emissions from wood burning in the UK by just 10 per cent over the next decade, but campaigners said the measures ‘don’t go far enough.’