Protecting against COVID-19 as we consider when and how to gather in person again

UCUCC COVID-19 Action Team and the Facilities & Equipment Committee

The main infection risk for Covid-19 is proximity and duration: the closer we are to someone else and the longer we are near them, the more likely we are to encounter enough virus particles to become infected. Wearing a mask helps filter the number of aerosols that you emit when talking as well as filtering the number of aerosols from other people that you are breathing in. But physical distancing is also important. The coronavirus particle is tiny: only 0.1 micrometers (a human red blood cell is 7.5 micrometers in diameter), and can remain suspended in the air for hours. The more talking or singing, the more particles are released [see diagram below]. Over time, a cloud of aerosols builds up around each of us. Staying more than six feet apart allows those particles to dissipate and reduces the chance that an infectious dose will get from one person to another. Time is another factor that you can control: the shorter time you are sharing space with someone else, the lower the risk.

If we each utilize these three precautions (mask wearing, physical distance, and a short duration) in an outdoor space, the risk of infection is very low. Indoor spaces are complicated, because more virus particles build up over time and can remain in the air for longer.

Consider how air flows through a building: stale indoor air is pulled out of the room as fresh air from outside is pumped into the building (where it passes through the filtration system before entering each room). Currently, our building recycles a lot of our air, which is more energy efficient and environmentally friendly, but could circulate small virus

particles throughout the building. By increasing our outside ventilation to the maximum and replacing our current air filters with MERV13, we can keep our air as clean as possible. MERV13 filters are rated to capture particles as small as 0.3 micrometers.

“It’s the combination of ventilation and filtration that results in the indoor air quality,” Dr. William P. Bahnfleth, Chair of the ASHRAE Epidemic Task Force said. “So if you’ve got a good level of filtration and a good level of ventilation, that could be sufficient in a lot of environments.” – Washington Post, June 26, 2020

As we consider how and when to re-gather in 2021, the COVID-19 Action Team and the UCUCC Facilities and Equipment Committee is looking at our ventilation and filtration systems, and investing in improvements that will keep us safe. We can improve our ventilation by bringing in as much outside air as possible, and ensure the air in each room is circulated several times an hour. We can improve our filtration by using MERV13 filters for our central recirculating systems, and consider portable HEPA filters for rooms that aren’t connected to our HVAC. The Facilities & Equipment Committee has approved funding for these projects, and implementation will begin in early 2021.

The COVID-19 Action Team is identifying needs, developing policy recommendations and drafting guidelines that are based on our community’s values as well as the best available science and public heath advice. Our building partners CLCC, Teen Feed, and UDYC have their own Covid-19 Safety Plans that follow state and county guidelines for child care organizations and social service agencies.

Diagrams from: https://english.elpais.com/society/2020-10-28/a-room-a-bar-and-a-class-how-the-coronavirus-is-spread-through-the-air.html