London broke the annual limit for air pollution just five days into 2017, according to data from the capital’s main monitoring system.

A site on Brixton Road in south London surpassed hourly limits for nitrogen dioxide concentrations 24 times so far this year, breaking the European Union’s annual permitted limit of 18 breaches, according to provisional data on King’s College London’s Air Quality Network website. The pollutant come from diesel engines in cars, trucks and other sources.

“Road traffic is the biggest culprit, and diesel is the worst,” Jenny Bates, a campaigner at the environmental group Friends of the Earth, said in a statement. “This is why the Government must take much bolder and quicker action including planning to phase out diesel by 2025. It’s scandalous that air pollution limits for the entire year have already been breached.”

The data show the UK is still far from complying with EU air quality regulations, which it has broken since 2010. Last year, it took eight days to pass the limit at a different London site on Putney High Street.

The World Heath Organisation estimates air pollution annually costs the UK £62bn pounds, and Mayor Sadiq Khan has made tackling the problem a priority of his administration. His office estimates illnesses stemming from long-term exposure to airborne pollutants cause as many as 9,400 deaths in the capital each year.

Mr Khan on Friday said in a statement he plans eight new low-emissions bus routes that will deploy the “greenest vehicles.” They include a route along Putney High Street and another one starting near Brixton Road. He also announced a £50m programme to give buses priority over other traffic, reducing so-called idling, where they keep their engines running while stopped because of lights or congestion.

ClientEarth, an environmental law firm, has successfully challenged ministers on air quality strategy twice, and the High Court ruled in November that the UK has broken the law by failing to adequately deal with pollutants. It ordered the Government to revise current plans to rein in toxic emissions to comply with EU standards.

The worst countries in the world for air pollution deaths Show all 10 1 /10 The worst countries in the world for air pollution deaths The worst countries in the world for air pollution deaths Ukraine A radioactive sign hangs on barbed wire outside a café in Pripyat. The worst countries in the world for air pollution deaths Bulgaria Mandatory Credit: Photo by NUKARI/REX (407890f) A power plant outside Sofia STOCK OF BULGARIA - FEB 2003 Rex Features The worst countries in the world for air pollution deaths Belarus The worst countries in the world for air pollution deaths Russia The worst countries in the world for air pollution deaths Armenia The worst countries in the world for air pollution deaths Bosnia and Herzegovina Women wearing masks walk in front of academy of fine arts as smog blankets Sarajevo, Bosnia and Herzegovina December 23, 2015. With severe air pollution affecting the city nestled among the mountains, the authorities have declared the first level of preparedness, advising the segment of the population that is at health risk to reduce movement in the mornings and evenings, appealing to drivers to use motor vehicles less and ordering heating utilities to lower the emission of harmful gases. REUTERS/Dado Ruvic REUTERS The worst countries in the world for air pollution deaths Georgia The worst countries in the world for air pollution deaths Hungary TOXIC SPILL, AJKA, HUNGARY-OCTOBER 9, 2010: This is an image of the toxic spill in Ajka, Hungary affecting the villages of Kolontar and Devecsar Hungary. (credit: DigitalGlobe) DigitalGlobe The worst countries in the world for air pollution deaths China The worst countries in the world for air pollution deaths Moldova

Concerns have also been raised by S&P Global Inc in a report that questioned whether Britain’s plan to exit from the EU will result in weakened air quality standards. Inside the 28-nation bloc, the UK is legally bound to comply with the regulatory thresholds. After it leaves, there is no guarantee the limits will still be observed.