The coronavirus lockdown across Europe has seen air pollution drop by as much as 50% in some cities.

The latest monitor from the European Space Agency (ESA) shows a continued fall in nitrogen dioxide levels across March and April.

The biggest drop was recorded in Paris, where levels fell by 54% between March 13th and April 13th compared to the same period last year.

Meanwhile, monitor shows a drop of 45% in Madrid, Milan and Rome.

A 54% drop in nitrogen dioxide levels was recorded over Paris. Image: ESA

The monitor was compiled by the Royal Netherlands Meteorological Institute using data from the EU’s Copernicus Sentinel-5P satellite.

The ESA said nitrogen dioxide has significant impacts on human health and comes from vehicles, power plants and industrial facilities.

A 45% drop in nitrogen dioxide levels was recorded over Madrid. Image: ESA

Henk Eskes, from the Royal Netherlands Meteorological Institute (KNMI) said levels have to monitored over months rather than days.

“There are considerable variations of weather in every country from one day to the next, creating a large impact on the dispersion of nitrogen dioxide,” he said.

“Averaging data over longer periods of time allows us to see clearer changes in concentrations owing to human activity.

“For this reason, the maps show concentrations over a monthly period and are provided with an uncertainty of 15% which reflects weather variability not accounted for in the monthly averages used.”

A 45% drop in nitrogen dioxide levels was recorded over Milan. Image: ESA

The Copernicus Sentinels are a fleet of EU-owned satellites that play a key role I the bloc’s environmental programme.

The ESA is in charge of the space component of the project.