Wildfire season complicates efforts to keep Berkeley schools safe from COVID-19

On bad air days, schools are instructed to close windows and doors and let the air purifiers work. But during the pandemic, that solution comes with its own problems.

View of a the San Francisco Bay from the Berkeley Hills on August 10.
At 100 AQI, teachers may elect to close windows. At 151 AQI, windows will be closed and pre-k, elementary, and middle school students will eat and exercise indoors in large rooms to maximize social distancing. Credit: Clara Mokri

Wildfire season could pose a challenge to Berkeley schools as they balance trying to keep students safe from the unhealthy air outdoors with reducing their chances of being exposed indoors to COVID-19.

School and district leaders typically follow guidance from the Bay Area Air Quality Management District and the Alameda County Office of Education for adjusting school activities when wildfire smoke causes poor air quality. But that guidance was established before the pandemic, when there were fewer concerns about keeping people indoors with windows and doors shut. Since COVID-19 spreads mainly through respiratory droplets and aerosols traveling through the air, schools have been encouraged to use air filtration devices and provide more outdoor spaces for students, especially during meal times when students take their masks off.

But wildfire season could necessitate shutting windows and keeping students indoors. The dual threat of polluted air and COVID-19 has left teachers, parents, and school leaders struggling to figure out what to prioritize, how to protect students, and how to make school as safe as it can be.

Promoting air flow in classrooms has been a foundation of COVID-19 mitigation efforts in schools. In the Berkeley Unified School District, all classrooms are equipped with HEPA 17 air purifiers.


California Department of Public Health recommends that ventilation systems be used to safely reopen schools, but emphasizes that they “should not be full replacements for outdoor ventilation.”

In Berkeley schools, windows are kept open to ventilate spaces with fresh air, but the district will have to rely on air filtration systems, along with other measures like universal mask wearing, to mitigate the spread of COVID-19 on especially smoky days.

At 100 AQI, teachers may elect to close windows. At 151 AQI, windows will be closed and pre-k, elementary, and middle school students will eat and exercise indoors in large rooms to maximize social distancing. Berkeley High will not require students to eat lunch indoors due to space constraints.

Research shows that wildfire smoke can exacerbate COVID-19 symptoms and increase the rate of reported COVID-19 cases, making it even more important to stay indoors on smoky days.

Meal times during wildfire season can be tricky for students and teachers, and some parents worry about the spread of COVID-19.

Liza Lutzker, who has a fourth grader at Sylvia Mendez and a sixth grader at Longfellow Middle School, is so worried about her kids eating indoors that she plans to keep her children home on smoky days if the AQI could exceed 151. Lutzker previously worked as an epidemiologist for California Department of Public Health and now works for UC Berkeley’s School of Public Health.

Other parents feel assured by the relatively low case counts coming out of the school’s surveillance testing program. “I’m not all that concerned with covid risk during high AQI days,” wrote Ben Gerhardstein, the parent of a second grader at Washington Elementary. “For me, the rates of covid are low enough that I’m comfortable with a few days here and there with windows closed.”

Berkeley public health officials say the district’s safety protocols will help prevent the spread of coronavirus, even on smoky days. “The combination of smoke and COVID-19 risks while challenging are manageable to address with existing protocols.  The school COVID-19 protocols ensure that schools are safer environments and they can be adjusted during poor AQI,” Berkeley Public Health wrote in a statement to Berkeleyside.

BUSD will consider closing schools if the AQI exceeds 201. “Decisions about school closures for very high AQI level events will take place on a case-by-case basis, given that every situation is unique,” the district’s safety plan reads.

Since schools started this August, AQI levels climbed to 101 only one day. Last fall, during a record-breaking fire season, AQI levels exceeded 150 in Alameda County on 11 days.

Since Aug. 1, BUSD has recorded 63 positive cases among students, out of just over 9,000 students and 1,775 staff. 71% of students are signed up for regular surveillance testing, and staff are required to be vaccinated or get tested weekly for COVID-19.

As of Friday, there were no students quarantining at home due to COVID-19 exposure and 135 individuals attending school in modified quarantine, which requires them to be tested twice weekly and refrain from extracurricular activities. The district has yet to report any outbreaks at a school site. Three cases of the coronavirus that are epidemiologically linked and occur within a 14-day period constitute an outbreak, according to guidelines from the California Department of Public Health.

Ally Markovich covers education for Berkeleyside. Email: ally@berkeleyside.org. Twitter: allymarkovich.