The death toll from tiny particulate pollution in London is on the brink of hitting 2,500 this year, according to new figures.
At least four boroughs - Barnet, Bromley, Croydon and Ealing - have seen the deadly impact of long-term exposure to human-made PM2.5 pollution rise above 100.
The analysis by Clean Air in London showed the total for the capital reached 2,475 today and is set to climb above 2,500 within days.
Levels of this type of toxic pollution, found by scientists to be particularly dangerous as it can infiltrate deep into the lungs and into the bloodstream, are worse in central London, including Westminster, and Kensington and Chelsea.
But the death toll is higher in several outer boroughs given their large populations.
''Even these shocking numbers understate the dangers we face,'' said Simon Birkett, founder of Clean Air in London.
''They exclude the effects of other air pollutants such as nitrogen dioxide (NO2) and other health effects such as reduced lung function in children for life.''
While new Mayor Sadiq Khan had ''woken up'' to the problem, he added, the government was failing to do enough to tackle it.
Nearly half of Londoners now say filthy air has impacted on their health, according to a new poll.
The TNS survey for London Councils also showed the figure was even higher among cyclists, 59 per cent, parents, 58 per cent, people living in inner London, 51 per cent, and those who had arrived in the capital in the last five years, 56 per cent.
The most common health problem which Londoners blamed on air pollution was breathing difficulties, 16 per cent of those citing symptoms, worsening asthma, 11 per cent, and coughing, nine per cent.
Nearly half of parents in the capital, 48 per cent, now say that the state of the air influenced their decision on picking a school for their children.
Fifty-four per cent of them say it is on their mind when thinking about where they live.
''The fact so many people reported a negative impact on their health, and concerns about the health of their children, is worrying and shows this continues to be an issue of huge significance in our city.''
He urged the government to draw up a new Air Quality Strategy and pass new Clean Air Act legislation so existing air pollution limits and targets are not scrapped due to Brexit.
Environmental lawyers ClientEarth will take the government back to court next week to try to force it to step up action to cut NO2 levels which are above EU legal limits in many parts of the city.
NO2 and PM2.5 are estimated to cause an annual death toll, the combined total of life lost due to these pollutants in London, equivalent to up to 9,400 lives.
ClientEarth chief executive James Thornton said: ''The air we breathe in this city is illegal and it harms the health of Londoners.
''The government needs to get a grip of this public health crisis.''
The government stressed it was ''firmly committed'' to improving air quality and that its latest report to the European Commission showed progress was being made.
A spokesman added, ''We know there is more to do, which is why we have committed more than £2 billion to greener transport schemes since 2011 and we will continue to work closely with the Mayor of London to improve air quality in the capital.''
Khan is proposing introducing a £10-a-day ''T-charge'' on the most polluting vehicles next year and an expanded Ultra Low Emission Zone, possibly a year early in 2019.
TNS interviewed 1,006 Londoners between September 12 and 15. Data are weighted.
(Also see: Schoolkids in Wales hard hit by air pollution: study)