Have you ever wondered how polluted the air you are breathing in your city is? According to the World Health Organization’s latest report on air quality, 80% of people living in urban areas across the world are exposed to air quality levels that exceed WHO limits. Newly elected London Mayor Sadiq Khan has made a bold decision to keep Londoners informed on exactly that, by setting up over 2500 toxic air monitors that will warn and advise the public on how to respond to local air toxicity. The mayor, who was elected in May, has taken several steps to crackdown on air pollution.

The air monitors will issue alert when pollution level reach “high” or “very high”, something that has happened several times this year in the British capital. The new system will go live by August 15th and will be set up on bus stations and river pier signs as well as 270 tube stations and 140 road signs on the busiest streets of the city.

The alerts will rely on a three-day ahead forecast about air pollution levels provided by airTEXT, an air-quality informative free text service provided to the residents of London.

“More vulnerable Londoners with particular health needs will continue to have access to the airTEXT service enabling them to get regular forecasts via text, voicemail, email, mobile app and online,” an official statement reads.

“We are working with the Mayor to deliver an ambitious and wide-ranging program to improve air quality across the Capital,” Leon Daniels, Transport for London’s managing director of Surface Transport explains, highlighting that “an important part of this work is to raise awareness and provide advice to people on how they can personally contribute to this work.”

In July, Khan proposed a daily GBP £10 (US $13) charge for the most polluting cars, mainly those registered before 2005. If approved, the “T-charge” will be applied next year as well as a diesel scrappage scheme.

“I am doing everything within my power as Mayor to put the health of Londoners first. I hope that these alerts will become less and less frequent as we take steps to make our already great city a cleaner place to live, work and study in,” Khan adds.