(TMU) — Over the years, air pollution in cities across the world had become the “new normal.” But now, in the midst in the worldwide pandemic, cities have become quiet as they are locked down with businesses closed and citizens forced to self-isolate.
As the streets are emptied of all vehicles except those needed for emergencies and essential services, the sky has started clearing and becoming bluer than it’s been for a very, very long time.
In London, Milan, Rome and Paris air pollution levels dropped drastically since the enforced shut downs in attempts to stop the spread of the highly contagious coronavirus.
Across the city of London, the levels of nitrogen dioxide, mostly emitted by vehicle exhausts, and levels of particulate matter, from road transport and burning fuel, have noticeably been reduced in a relatively short period.
According to scientists, PM2.5, an ultra-fine particulate matter, is down to about half the level it has been during this time of the year based on average measurement taken over the past five years.
Since mid-February, both pollutants have dropped by around half, according to data from the London Air Quality Network and analyzed by The National Centre for Atmospheric Science.
Meanwhile, the European Space Agency’s Sentinel-5P satellite confirmed that nitrogen dioxide levels are considerably lower over London compared to March 2019.
Traffic and pollution levels across Europe have dropped amid the #COVIDoutbreak. @DescartesLabs processed data from #Sentinel5P satellite and compared it to March 10-22 of last year. Here's what they found: pic.twitter.com/YoLx2Cm90p
— Pattrn (@pattrn) March 25, 2020
A similar pattern is seen in other European cities. The air pollutant concentrations in Rome have seen a drop of 50%, and by 30% in Paris, according to data from the European Environment Agency.
The huge reduction of traffic pollution in London follows the restrictions on her citizens from gathering in groups and moving around freely, other than for necessary work, emergencies, shopping for essentials like food and medicines, or one form of daily exercise as part of precautionary measures during the pandemic.
Professor Alastair Lewis, from the National Centre for Atmospheric Science, University of York, told the Daily Mail:
‘’Air quality has started to improve in many UK cities, mirroring what has been seen in other countries that have restricted travel and levels of outdoor activity.
This is primarily a consequence of lower traffic volumes, and some of the most clear reductions have been in nitrogen dioxide, which comes primarily from vehicle exhaust.
However fine particles (PM2.5) have also reduced significantly.
In London for example, PM2.5 is noticeably lower than would be expected for this time of year at the roadside, and these reductions stretch through into the suburbs as well.’’
Professor Lewis emphasized the importance of the change in PM2.5 levels compared to what we would usually observe during this time of year. He explained that ‘’air pollution is noisy and often changes based on the weather, and therefore it’s best to compare where we are now against where we might have expected to be based on previous years’’.
Although the current data seem to show reductions in pollution resulting in improved air quality, it seems fair to assume that once travel restrictions are lifted, pollution levels will probably rise to pre-2020 levels. Unless, of course, seeing the blue sky again inspires us to work towards finding a more permanent solution to reduce traffic in our cities.