It's here! The final, peer-reviewed version of our #openaccess manuscript, Room-level Ventilation in Schools and Universities doi.org/10.1016/j.aeao… (1/) Good ventilation is an important tool for keeping our indoor environments healthy - both to reduce the spread of respiratory diseases like flu and COVID-19, and for indoor air quality. However, we're missing classroom-level data on ventilation in many schools and unis (2/)

A short thread to clear up some questions I'm hearing a lot re: masks:

All masks have 2 functions: (1) catching droplets and particles exiting your mouth & nose and (2) filtering what you breathe in. Cloth masks are pretty good at (1) and just OK at (2). (1/) That point (1) is why even cloth masks help reduce transmission when everyone is wearing one.

Well-fitting masks made of synthetic woven material designed to filter such as KN95, KF94, or N95 (a.k.a. "respirators") are excellent at both (1) and (2). (2/)

Between omicron, test shortages, and policy changes moving in the direction of ¯\_(ツ)_/¯, you may find it reassuring to know that the engineering guidelines for ventilation, filtration, & filtering masks were developed for basically this situation. They're based on tests and calculations assuming there are infected people near you in a space, looking at how much ventilation would be needed, or how air would need to be filtered, in order to prevent them infecting others.

NEW PREPRINT: Room-level Ventilation in Schools and Universities bit.ly/3lUi2FC

This new manuscript came out of a unique collaboration with @ShellyMBoulder @HuffmanLabDU @CorsIAQ @rsegalman @PollittKrystal @polsiewski @doyoung_maeng & many others. (1/ ) We know ventilation is a key part of the layered "Swiss cheese" approach to reducing transmission of airborne diseases including COVID-19. But as schools and universities ramp up to open with increased capacity, many don't have room-level ventilation data for their spaces. (2/)