Yifang Zhu in CNN: Los Angeles has notoriously polluted air. But right now it has some of the cleanest of any major city

With the city — and the entire state of California — under stay-at-home orders to stem the deadly outbreak of coronavirus, something dramatic has happened to the air in LA. Beginning in early March of this year, EPA air quality data shows that the city of Angels experienced its longest stretch of “good” air quality since at least 1995.  Dr. Yifang Zhu, a professor of environmental health sciences at UCLA’s Fielding School of Public Health and Institute of Environment and Sustainability, said that she and her colleagues found a 40% drop in levels of PM 2.5, a class of microscopic air pollutants that have been linked to serious cardiovascular and respiratory problems, especially in children and the elderly.