While many of us are enjoying clearer skies and fresh-smelling air, new research shows it’s not all good news when it comes to improved air quality.
There’s no doubt that a reduction in air pollution has been one of the silver linings of Covid-19. Research by the American Geophysical Union have shown that levels of nitrogen dioxide pollution over northern China, Western Europe and the US have decreased by as much as 60 percent in early 2020 compared to the same time last year. Nitrogen dioxide is particularly harmful to the lungs. It typically enters the air through emissions from vehicles, power plants and industrial activities. Likewise particulate matter pollution – which is also damaging to the lungs – has also decreased.
Time for new pollution regulations
The improvements in air quality will likely be temporary, but the findings give scientists a glimpse into what air quality could be like in the future as emissions regulations become more stringent, according to the researchers.
“Maybe this unintended experiment could be used to understand better the emission regulations,” said Jenny Stavrakou, an atmospheric scientist at the Royal Belgian Institute for Space Aeronomy in Brussels and co-author of the research. “It is some positive news among a very tragic situation.”
The downside of the drop in nitrogen dioxide pollution is an increase in surface ozone levels in China. Ozone is a secondary pollutant formed when sunlight and high temperature catalyse chemical reactions in the lower atmosphere. Ozone is harmful to humans at ground-level, causing pulmonary and heart disease.
Although air quality has largely improved in many regions, surface ozone can still be a problem, according to Guy Brasseur, an atmospheric scientist at the Max Planck Institute for Meteorology in Hamburg, Germany, and lead author of one of the new studies. “It means that by just reducing the [nitrogen dioxide] and the particles, you won’t solve the ozone problem,” Brasseur said.