Domestic wood burning has become the single biggest source of small particle air pollution in the UK, producing three times more than road traffic, government data shows. Just 8% of the population cause this pollution by burning wood indoors, according to a separate government-commissioned report. It found almost half of those burning indoors were affluent and many chose a fire for aesthetic reasons, rather than heat. Tiny particle pollution is harmful to health as it can enter the bloodstream, be carried around the body and lodge in organs. The government is not planning a ban on wood burners but a ban on the retail sale of wet wood will come into force on 1 May, as will a ban on bags of house coal, the first such restrictions since the clean air acts of the 1950s. Wet wood has not been seasoned and produces higher levels of pollution. The new government statistics show that domestic wood burning in both closed stoves and open fires was responsible for 38% of the pollution particles under 2.5 microns in size (PM2.5) in 2019, the latest year for which data is available. The report said PM2.5 emissions from this source had more than doubled since 2003, to 41,000 tonnes a year, and increased by 1% between 2018 and 2019. Road traffic caused 12% of PM2.5 in 2019. In the 1970s and 80s, coal fires in homes were the primary source of small particle pollution but these now account for a very small proportion of PM2.5s, the report said. This fall, and cleaner vehicles and industry, mean overall particle pollution levels have fallen significantly since 1970, but they have levelled off in the past decade. “This reflects the increasing popularity of solid fuel appliances in the home such as wood-burning stoves,” the report says. “Due to the small size of [particulate pollution] some of these toxins may enter the bloodstream and be transported around the body, lodging in the heart, brain and other organs. Therefore, exposure to PM can result in serious impacts to health.” Wood burners also triple the level of harmful pollution particles inside homes and should be sold with a health warning, scientists warned in December. In January, experts at Asthma UK and the British Lung Foundation asked people to use wood burners only if they had no alternative source of heat. Prof Jonathan Grigg, of Queen Mary University of London, said: “It is difficult to justify their use in any urban area.” The second report, produced by Kantar for the government, examined who was burning solid fuels at home and why, and included a survey of 46,000 people. It found that just 8% of people in the UK burned fuel indoors, with two-thirds of them living in urban areas where levels of dirty air were worst. Two-thirds of the people burning indoors used a stove, while a third had open fires, and 96% had alternative sources of heating such as gas or electricity. Most of the indoor burners used seasoned wood but 20% were using wet wood, the research found. “The most common reasons they gave for using their indoor burning appliance were to create a homely feel, so they could heat just one room, to save money, and/or because they liked the look of a fire,” the report says. “Habit also seemed important: 79% of indoor burners reported having a fire at home when growing up as opposed to 23% of [those never burning at home].” Almost half the indoor burners (46%) were from the highest AB social grades, which represent about a quarter of the population overall. The researchers identified five types of indoor burners, including people who burned as a “lifestyle choice” for aesthetic reasons (28%) and for reasons of tradition (18%). A small number, who tended to be older, less affluent and more rural, had no other heating (8%). The rest burned at home to save money or supplement other heating. The research also found that less than a third [of indoor burners] said they were concerned about the effects burning might have on their health or those around them. “We have 8% of UK homes that are responsible for about 40% of PM2.5 pollution,” said Gary Fuller of Imperial College London, a member of the government’s air quality expert group. “Wood burning in homes has crept up under the radar while we all focused our attention on diesel traffic.” “We can count cars and lorries on our roads to understand the pollution that comes from traffic. But we have very little idea of what people are doing in their own homes and hence the importance of this [Kantar] survey,” he added. “One of the ways to tackle wood burning is to get more information out to people, as they have in New Zealand, to encourage people to burn their wood better. We have to engage and the starting point is to know who is burning wood and why they are doing so, and that is what this survey does.”