There is one positive impact of the tragic coronavirus pandemic — Los Angeles is experiencing its longest stretch of good air quality since 1995. On April 7, Swiss air quality technology company IQAir cited LA as one of the cities with the cleanest air in the world. While the notoriously smoggy city is on lockdown, highway traffic has dropped 80% throughout the entire state of California, which probably accounts for much of the improvement.
“With less cars on the road and less emissions coming from those tailpipes, it’s not surprising to see improvements in the air quality overall,” Yifang Zhu, professor of environmental health science at UCLA, told CNN. Zhu and her team of scientists measured a 20% overall improvement in southern California’s air quality between March 16 and April 6. They also recorded a 40% drop in PM 2.5 levels. This microscopic air pollutant is linked to both respiratory and cardiovascular problems, especially in the very young and very old. A recently released Harvard study linked PM 2.5 exposure to an increased likelihood of dying from COVID-19.
All over the world, scientists are noting that cleaner air is a side effect of the pandemic. Satellite images have revealed much lower concentrations of nitrogen dioxide over industrial areas of Europe and Asia in the past six weeks. The drops in nitrogen dioxide levels over Wuhan — a city of 11 million — and the factory-filled Po Valley of northern Italy are especially striking.
“It’s quite unprecedented,” Vincent-Henri Peuch, director of the Copernicus Atmosphere Service, told the Guardian. “In the past, we have seen big variations for a day or so because of weather. But no signal on emissions that has lasted so long.”
Alas, when lockdowns lift and Angelenos return to the highways, the pollution will likely return. Zhu hopes that this glimpse of clear, blue skies will inspire people to work for better air quality post-pandemic.
“From the society level, I think we need to think really hard about how to bring about a more sustainable world, where technologies and policies come together to bring us cleaner energy,” she said. “So that the air that we’re breathing will stay as clean as what we’re breathing today.”
Image by Joseph Ngabo