This article is more than 3 years old

This article is more than 3 years old

They take their inspiration from the well-known signs linking people from the past with the buildings they once inhabited, but the symbols now appearing across London are to highlight a different connection.

In the past week, grey plaques – direct copies of the English Heritage blue plaques identifying the homes of the dead and famous – have been put up on buildings across the capital to identify streets and houses in areas where air pollution threatens public health.

Each plaque carries the phrase London’s Choking to point out areas where levels of NO2 – predominantly from diesel traffic – regularly reach levels that are harmful to human health.

Joe Dennett and Rob Donaldson came up with the idea to try to raise awareness of the invisible threat from air pollution to tens of thousands of Londoners.

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“It is an issue which Londoners are becoming more aware of, and which we have become increasingly concerned about. But we realised a lot of people were not aware of where pollution levels are high because you cannot see the pollution, it’s quite nebulous.

“We wanted to try and create awareness and anger about it at grass roots and to come up with something that would identify the air pollution.

“The English Heritage blue plaques highlight the invisible past of a building and this is trying to highlight the invisible danger of the pollution in the areas where the grey plaques are being put up.”

The first plaque – with a skull and crossbones at its base – appeared on Brixton Road, which by 4 January this year had breached annual legal limits for NO2 pollution. Further plaques in Putney High Street, Farringdon Street and Oxford Street have also been erected.

Facebook Twitter Pinterest ‘We realised a lot of people were not aware of where pollution levels are high ... it’s quite nebulous’: Joe Dennett from London’s Choking. Photograph: Linda Nylind/The Guardian

The plaques were put up in the week after the government was forced by the high court to publish its new air quality draft plan to tackle illegal levels of NO2 pollution. Ministers have twice lost in the high court after their original plans were challenged by the environmental law firm Client Earth.

But the government’s latest policy – published on 5 May – has, say campaigners, fallen short again. It contains no commitment to a diesel scrappage scheme to subsidise the public to get rid of their diesel vehicles and also fails to mandate local authorities to impose charges on drivers of diesel cars in clean air zones.

The draft plan has been condemned as “woefully inadequate” by Client Earth. The government has to produce a full plan by 31 July.

While English Heritage has 900 blue plaques across London, Dennett and Donaldson are just beginning to identify air pollution blackspots with their grey plaques.

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As well as on streets and main routes through London, the pair have put up plaques outside schools in areas where air pollution exceeds legal limits. Figures released by the mayor of London, Sadiq Khan, revealed in February that more than 800 schools in London are in areas where NO2 pollution is above legal limits and considered harmful.

Khan said: “Toxic air causes more than 9,000 early deaths every year in London, as well as stunting the growth of children’s lungs, causing dementia and strokes. Londoners are understandably concerned about the possible damage to their health of living in high pollution areas and want to make informed choices.

“That’s why I’m writing a new London plan with policies in place to make sure pollution levels are considered when deciding where to build new homes and schools in London, as well as a whole host of other measures to make our air cleaner.

“The Tories are refusing to take any action to clean up our dangerously polluted air, while Labour is delivering the most ambitious clean-air plans of any city on the planet. The best way to clean up our air is to vote Labour.”

Nationally, a Guardian and Greenpeace investigation revealed that more than 2,000 schools and nurseries are within 150 metres of a road where NO2 exceeds the legal limit for long-term exposure of 40 micrograms per cubic metre.