View from the Lawrence Hall of Science on Aug. 10, 2021. Credit: Clara Mokri

Update, Monday, Dec. 19 The Bay Area Air Quality Management District has extended the Spare the Air alert in Berkeley though Tuesday.

Original story, Sunday, Dec. 18 The Bay Area Air Quality Management District is warning of high pollution and hazy skies Monday, issuing its 11th “Spare the Air” alert of the year.

Smoke from fireplaces and wood stoves, combined with stagnant days, are forecast to cause fine particle pollution, also known as PM 2.5, to build up across the Bay Area, including in Berkeley, said Aaron Richardson, spokesperson for BAAQMD. (Per the name, PM 2.5 particles generally have a diameter of around 2.5 micrometers, or about 30 times smaller than the width of a single strand of hair, and can easily be inhaled.) 

It’s illegal to burn wood when a Spare the Air alert is in place.

“We issue Spare the Air Alerts Bay Area-wide, partly because of the potential for transport of pollutants from one part of the region to others,” Richardson said in an email. “In this case, the alert is based on our forecast of above 100 on the AQI scale (above the federal health standard) for the Northern Zone and Santa Clara Valley in the Bay Area.”

In the East Bay, the air quality index is expected to stay in the moderate  “yellow” level Monday, according to the BAAQMD forecast. Those who are “unusually sensitive” to particulate pollution should consider limiting the time they spend exercising outdoors.

Most of the Spare the Air alerts issued by the BAAQMD this year have been due to ozone pollution, or smog, and attributed to the combination of hot days, wildfire smoke and automobile exhaust. 

In 2021, the Bay Area saw 16 Spare the Air days, five of which were attributed to PM 2.5. In 2020, it had 52 total days, 46 of which were attributed to PM 2.5, thanks to a severe wildfire season.

Avatar photo

Iris Kwok covers the environment for Berkeleyside through a partnership with Report for America. A former music journalist, her work has appeared in the San Francisco Chronicle, KQED, San Francisco Examiner...