One in four of London’s green spaces breaches air quality safety limits

More than one quarter of London’s parks, playground, and open spaces exceed international safety limits for air quality.

The researchers warn this could potentially put thousands of children and vulnerable Londoners at risk.

In an analysis of the annual air quality levels in green spaces across the capital’s 33 boroughs, researchers from Imperial College London and the University of Leicester used nitrogen dioxide (NO2) estimates, comparing them against safety limits set by the European Union and World Health Organisation. They found that 24% of play spaces and 27% of public parks had NO2 limits exceeding safety standards, with 67% of private parks failing to keep within safe levels. The closest play space for 250,000 children under the age of 16 (14% of the city’s children) had NO2 concentration averages exceeding European Union limits, with the majority of children affected living in the most deprived areas of the city.

The findings, published recently in the International Journal of Environmental Research and Public Health, used data (breaking London into a grid of 20 metres squares) from the London Atmospheric Emissions Inventory (LAEI), developed by King’s College London.

Using data from 2016, the latest estimates available, the Imperial team applied measures from the closest grid squares to green spaces to give an NO2 average for the year for 4,470 parks, gardens and open spaces. Census data from 2011 provided information on number of children under the age of 16 in close proximity to green spaces.

The European Union safe limit for NO2, in accordance with the World Health Organisation, is set at an average of 40 µg/m3 per year.

The highest average annual levels of NO2 in green spaces were found in inner London boroughs, with City of London, Westminster, Camden, Kensington and Chelsea and Islington having the highest levels of all London boroughs. Five of the 10 most polluted parks in London were found in Westminster, and the worst air quality was found to be Victoria Embankment Gardens (annual average NO2 59.7 µg/m3) and Parliament Square Gardens (58.7 µg/m3). The researchers will unveil an online platform that allows people to explore air pollution levels in their local parks and playgrounds at an event hosted at Imperial this week. The full report can be access on the Imperial College news page