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 earlier this week, and researchers say that early signs are that the restrictions that have been imposed are likely to bring nitrogen dioxide levels in the capital down.
This charts on this web page will be updated daily with latest data showing NO2 concentrations at some of London's most polluted locations.
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A note of caution: 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. 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.