It should come as no surprise that the air quality in Sun Valley as well as other areas throughout Southern California has improved over the last month. Residents have curtailed the vast majority of their travel, limiting it to occasional trips to the grocery store or other necessities.
The decrease in traffic has been felt across the Southland as citizens stay home and off the streets. In an article on the Calmatters website, the amount of traffic on our roads has decreased by 51% according to data from the EPA and UCLA. Particulate matter in the air has dropped by 25% (on average) in Los Angeles and surrounding counties in the period from when the shutdown began to today. Other pollutant levels have also decreased dramatically.
Traffic levels do play a role in pollution levels, however experts also factor in our recent series of rains. Rain itself has a cleansing affect on air quality and with successive storms sweeping through Sun Valley in recent weeks, coinciding with our COVID-19-induced sheltering in place, it too has most likely contributed to cleaner air.
Once the country and state start to open up, coupled with the fact that the rainy season will have ended, we can expect air pollution levels to rise once more.