Covid-19 lockdowns have seen air pollution levels plummet across areas that have put restrictions in place, including China, northern Italy and European cities, data shows.
London's own lockdown began in late March, with data showing the controls have had a clear impact on nitrogen dioxide (NO2) levels.
But with evidence that the environmental benefits of lockdown may have been shortlived in European cities as commuters shun public transport and use their cars instead – and air pollution in China back to pre-crisis levels – how will the easing of Covid-19 control measures impact pollution levels in the capital?
This charts on this web page will be updated daily with latest data showing NO2 concentrations at some of London's most polluted locations.
CORONAVIRUS LIVE BLOG: The impact on green policymaking and implementation
A note of caution: 2020 data is provisional and has yet to be ratified. Numerous factors may influence air quality, including weather, human activity and new regulations, and this year's data must be viewed in the context of improvements in air quality in the capital. The charts above show NO2 concentrations at roads which were among London's busiest prior to lockdown - similar trends may not necessary be observed at urban background sites. They do not show trends in PM10 and PM2.5 levels.
While air quality remains a serious problem in London, figures published by the mayor's office in February showed a 97.5% reduction in hourly NO2 exceedances between 2016 and 2019.