Researchers from the clean-air research firm IQAir had been studying the amount of dangerous particles in the air over the ten cities that have been hardest hit by the coronavirus pandemic. The study compared levels of harmful microscopic particulate matter known as PM 2.5. The pollutant, which is smaller than 2.5 micrometers in diameter, is considered particularly dangerous as it can lodge deep into the lungs and pass into other organs and the bloodstream, with has been linked to serious long-term health risks.
In the three weeks that a major stay at home order has been in place across the world, seven out of the ten cities studies had seen a major reduction in PM 2.5 particles in the atmosphere. New Delhi, Seoul, Wuhan and Mumbai, Los Angeles, and others had seen up to a 60% decrease, which will make their air the cleanest it's been since the 1980s.
The report's authors say that while they do expect air pollution to rise again when economies restart after coronavirus, "out of these extraordinary circumstances, we can see how changes in our society's activities can have a momentous impact on our environment and the air we breathe," said IQAir's marketing specialist Kelsey Duska.
"In our recovery from the pandemic, it's important that we strive to preserve the cleaner environment, which protects our health from another invisible killer, air pollution," she said.
"We hope that the urgency in tackling this global pandemic may be matched in addressing air pollution."
The air in Los Angeles has been within the Environmental Protection Agency's Air Quality Index's standards for good air, the first time it's been within good ratings in years.
“We’re seeing very clean air all around California,” says Bill Magavern, policy director with the Coalition for Clean Air. “This time of year we usually have better air, especially with the rain, but the drop-off in traffic has definitely reduced emissions.”