One in four UK homes are surrounded by air pollution exceeding safety limits set by the World Health Organization, a study has shown following research revealing that road pollution affects virtually every part of Britain. Nearly 8m UK addresses are affected by high levels of particulate matter or nitrogen dioxide, the study commissioned by campaigning group the Central Office of Public Interest (Copi) showed. Researchers at Imperial College London used computer models to produce estimated concentrations of the levels of three toxic pollutants – PM (particulate matter) 2.5, PM10 and NO2 – at each address, accurate to 20 sq metres (24 sq yards). The results have been compiled into a searchable national database, where people can input an address to receive a rating of low, medium, significant, high or very high, with anything above “medium” meaning the address exceeds the limit for a pollutant. The study follows research revealing that 94% of land in Great Britain has some pollution above background levels, despite roads occupying less than 1% of the country. The University of Exeter study found that the most widespread pollutants are tiny particles, mostly from fossil fuel burning, nitrogen dioxide from diesel vehicles, and noise and light. More than 70% of the country is affected by all of these, with the only land to escape road pollution being almost entirely at high altitudes, affecting wildlife as well as seriously harming human health. Research indicates that air pollution at up to 500 metres (547 yards) from roads damages human health. Copi is pushing for legislation to compel estate owners and other property managers to list air pollution levels when advertising properties, having obtained a legal opinion from a QC stating that there is a “strong argument” that estate agents would be in breach of the Consumer Protection from Unfair Trading Regulations 2008 if they failed to inform customers about potential health risks. The Copi founder, Humphrey Milles, called for transparency around the risks of air pollution: “Air pollution affects everyone. It is a dangerous, invisible killer. With this national rollout, it would be shameful for the property industry to not start acting in an honest, transparent way. Lives depend on it. Everyone has a right to know what they’re breathing.” Jemima Hartshorn, the founder of the campaign group Mums for Lungs, described the statistics as “shocking”, but said the group was pleased the data was now publicly available. “We hope it will really help to raise awareness of the high levels of air pollution that are making so many of us sick. We really need to see urgent action on this and foremost we continue to call on the government to commit to reaching WHO levels, at the very latest by 2030 for all major pollutants across the UK,” Hartshorn said. “We also need to see the government committing real funds to addressing this issue, and providing many more cities with progressive clean air zones. We need to finally address the issue of wood burning that has become the major contributor to particulate matter across the country.” The UK government is planning a £27bn expansion of England’s road network, but the Guardian reported in February that the transport secretary, Grant Shapps, had overridden official advice from civil servants to review the policy on environmental grounds. It has been a legal requirement to take into account the environmental impact of such projects since 2014. Dirty air is estimated to cause 40,000 early deaths a year in the UK.