London’s air pollution history – the Victorian pea-souper fogs, the deaths of 12,000 people in the 1952 smog and the Clean Air Acts that followed – are well known. Dublin, just 285 miles (460km) away, has a different history. Here it was smog in the 1980s that prompted a ban on the sale of bituminous, or “smoky” coal in 1990. Smoke pollution dropped by 70% and there were 17% fewer deaths from breathing problems. The ban was rolled out to other Irish towns and many of these also recorded a reduction in winter deaths.

A new study has revealed that an old menace has returned to Dublin. Although the coal ban worked in the 1990s, it did not address smokeless coals and solid fuels. Wood and peat are marketed as slow-renewable, green or carbon-neutral biofuels, but their air pollution impacts can be significant. During three weeks in November and December 2016, Dublin breached World Health Organization guidelines for particle pollution on eight days. Chemical analysis of the pollution at these times showed the dominance of peat and wood smoke in the evenings. Overall, the home burning of solid fuel by just 13% of homes was responsible for 70% of the city’s particle pollution.