Sacramento region’s air quality expected to improve as coronavirus order cuts traffic
One bright spot amid the coronavirus pandemic: The Sacramento region has been experiencing relatively clean air this spring.
While it’s still too early to tell, local air quality experts say they expect reduced pollution levels in the coming weeks as thousands of cars and trucks are kept off the road following California Gov. Gavin Newsom’s order last week for all residents to stay at home except for essential chores or jobs.
For the last three weeks, the region’s air for particulate matter (PM2.5) on the Air Quality Index has been rated “good” except for two days, which were “moderate.” It’s an improvement from the air quality in January and February, according to data from Sacramento Region Spare The Air.
Jamie Arno of the Sacramento Metropolitan Air Quality Management District said 70 percent of ground-level ozone air pollution is caused by cars and trucks. With fewer vehicles on the road, “it makes sense that air quality has improved.”
The Bay Area has also seen drops in smog levels, as motor activity and industrial work has been slashed in recent weeks to rein in the spread of the coronavirus.
“Some of it is too early to tell,” said Paul Hensleigh, deputy air pollution control officer for Yolo and Solano counties. ”We’d certainly expect that to help.”
Erik White, Placer County’s air pollution control officer, asked his monitoring staff Monday to investigate the connection between better air quality and the stay-at-home order.
“We’re going to start taking a look at that to try to understand, ‘Is there a silver lining to everything going on?’” he said.
But Arno said air quality in the spring is generally pretty good, so it’s hard to draw the conclusion that the stay-at-home order is the cause of cleaner air in Sacramento.
“I’d expect to see the levels in good to healthy and maybe some levels in low to moderate, and that’s exactly what I’m seeing,” Arno said. “Even if the normal amount of trucks and cars were on the road.”
It might be a very different story in the summer, Arno said, when high temperatures and strong pressure systems would exacerbate ground-level ozone air pollution.
“Let’s hope we’re not talking about this in the summer,” Arno said.
One unexpected way the coronavirus is impacting air quality — with more people at home during the weekdays, more residents in rural parts of the region may limb the trees, thin the bushes and cut the grass of their properties to burn the excessive vegetation and create defensible space around their homes in preparation for wildfire season.
“Now is the time of year a lot of people are doing burning,” said Dave Johnston, El Dorado County’s air pollution control officer. “We issue a lot of burn permits (and) we anticipate that activity increasing.”
Burning has a significant impact on air quality, Johnston said, but not nearly as much as massive wildfires that might otherwise rip through the populated rural landscape.
With more people working from home given the stay-at-home order, “hopefully they are using that time to make their homes more defensible,” Johnston said.
Under the order, residents can still go out for bike rides, walks and hikes to enjoy the fresh air, so long as 6 feet of distance between each other is maintained.
This story was originally published March 23, 2020 at 2:02 PM.