Air quality has improved dramatically in nine major cities around the world, as people seek shelter in their homes to prevent the spread of the new corona virus, a new report finds. The report, compiled by the Swiss company IQAir, gathers government data from Delhi, London, Los Angeles, Milan, Mumbai, New York City, São Paulo, Seoul, Wuhan and Rome.
Places typically suffocated by worse air pollution saw the most extreme drops in fine dust or soot. Delhi saw pollution decline by 60 percent in three weeks, while home ordering took effect compared to the same period last year. Seoul, South Korea saw a 54 percent drop. Soot in Wuhan, China, dropped 44 percent.
IQAir produces air purifiers and pollution monitors, but also maintains online air quality maps. A interactive real-time map – a collaboration between IQAir and United Nations environmental and sustainability programs – provides information on the air quality index in major cities, along with a ranking of where air pollution is worst.
The data supports previous observations of how the sky cleared up during the pandemic when non-essential businesses were shut down and planes, trains and cars emptied. In early March, NASA shared maps of a dramatic drop in China of another pollutant emitted from tailpipes that ignite the airways, nitrogen dioxide. NASA also saw one 30 percent discount in nitrogen dioxide emissions in the northeastern United States in March.
Rome was the only one of the 10 cities to actually see an increase in soot over the three-week period. More people using their heating systems at home could be a culprit for poorer air quality, according to the report.
Cleaner air is a welcome respite during a pandemic caused by a virus that attacks the lungs, but it is not predicted to last long. Air pollution is expected to recover after the restrictions identified during the pandemic have broken down. Similar rebounds have been observed with air quality and greenhouse gas emissions after other economic shocks such as the 2008 recession.