Thread by @CorsIAQ

1/ Important study of over 10,000 classrooms.

Upshot = lowering concentration of virus-laden respiratory aerosol particles in classroom air lowers inhalation dose of these particles and significantly reduces infection. Always been about this, folks.

reuters.com/world/europe/i…

2/ Increasing ACH from lower than 2.4 to 2.4/hr - infections reduced by 40%. To 4 ACH lowered by 66.8%, to 6 ACH lower by 82.5%. With an appropriately-sized portable HEPA system or a #CorsiRosenthalBox we cannot achieve 10 ACH.

3/ "If the most efficient systems were installed "we could pass from 250 cases per 100,000 students (the alert level set by the education ministry) to a rate of 50 per 100,000."

Yep, its about lowering inhalation dose to virus-laden respiratory aerosol particles.

4/ Lower the concentration of virus-laden respiratory aerosol particles in classroom air by increased ventilation or appropriate filtration & you lower inhalation dose to those particles and reduce infections.

5/ Been that way from the start & has never changed. Along w/ many other dedicated colleagues, we've been speaking w/ the media, giving webinars, writing papers, op-eds, letters & more to try to get across importance of airborne respiratory aerosol particles & actions to lower.

6/ It's been so darn obvious (& frustrating) for 2 yrs.
We have had the tools all along to dramatically reduce inhalation of virus-laden aerosol particles in classroom and other building air, but largely failed (miserably) to make use of those tools.

7/ I've written often that to implement exceptionally effective tools in classrooms costs less than 0.03% of the cost of educating 1 student in the US. Perhaps over 2 yrs beyond the obvious we can start prioritizing health of students & their families in an effective way.

8/ And in doing so we can also makes school environments healthier during wildfire season, & for students and teachers with allergies, asthma, and more. None of this is rocket science, folks. Just do it!

Big goof. That should have been we CAN achieve 10 ACH as an equivalent --- ventilation + filtration ACH.