Legal air pollution limits for the whole year have been breached within a month in London, figures show.
On January 31, Brixton Road, Lambeth, broke the rules on nitrogen dioxide, which say concentrations of the pollutant should not exceed maximum permitted levels for more than 18 hours a year.
But experts monitoring pollution in the capital said the date marked “an important departure” from a trend which had seen the limit breached in the first week of the year since 2004 in the capital.
Data from London Air Quality Network at King’s College London shows decreases in nitrogen dioxide concentrations along Putney High Street, Brixton Road and Oxford Street over the last two years.
This is probably due to better real-world emissions performance of the latest heavy goods vehicles and upgrades to London’s bus fleet, with Putney High Street and Brixton Road both becoming “low emissions bus zones” in 2017, the experts said.
But annual averages of nitrogen dioxide for both roads are well above legal limits, the data show.
Air pollution is linked to the early deaths of about 40,000 people a year in the UK and causes problems such as heart and lung disease and asthma.
Gary Fuller, from the Environmental Research Group at King’s College London, said: “Since 2010, nitrogen dioxide alongside most of London’s roads has started to improve and it is good news to see that this trend is continuing at some of London’s most polluted locations.
“However, while press and public attention will focus on today’s measurements at Brixton Road, it is important to note that the majority of main roads in London regularly breach legal values for nitrogen dioxide.”
Environmental groups have called for the Government to take urgent steps to tackle illegally dirty air, including creating and funding clean air zones in pollution hotspots across the UK where 85% of areas still break rules which should have been achieved in 2010.
Government estimates suggest compliance for levels of nitrogen dioxide, much of which comes from road transport, particularly diesel, will not be met until 2026.