LONDON: Air pollution from nitrogen dioxide has fallen by an estimated 40 per cent in three European cities, according to new satellite data released by the European Space Agency (ESA), coinciding with a widespread lockdown to curb the spread of the coronavirus.

The space agency's Copernicus Sentinel-5P satellite mission on Friday released three composite images showing nitrogen dioxide concentrations in the period Mar 14-25 over France, Spain and Italy, compared to the monthly average of concentrations from 2019.



A combination image from the ESA shows the average nitrogen dioxide concentrations from air pollution across France

"This is a first level estimate; some of these values have gone down by about 40 per cent of the normal value ... so a very drastic decrease," Josef Aschbacher, ESA Director of Earth Observation Programmes, told Reuters via a video call.

Researchers studying the impact of emissions from industry and transport on climate change and human health are scrambling to understand the possible implications of the coronavirus pandemic as economies slow, flights are disrupted and quarantines imposed.

A combination image from the ESA shows the average nitrogen dioxide concentrations from air pollution across Italy



"What you really see are the centres of this pollution … It is quite a good first level indicator of anthropogenic pollution coming from traffic and industry," added Aschbacher.

Nitrogen dioxide, a noxious gas emitted by cars, power plants and factories, is blamed for some respiratory and heart conditions.

A combination image from the ESA shows the average nitrogen dioxide concentrations from air pollution across Spain

Almost every city-dwelling European is exposed to pollution levels that exceed healthy levels, according to a 2019 report from European Environment Agency (EEA).

