In this one image (@LakeyPascale et al) we can learn a lot about how to manage airborne pathogens: mask up, filter, and ventilate...
But also heed a cautionary tale about the known (and yet unknown) hazards of using chemical reactions to "clean" our indoor air. 🧵1/
But also heed a cautionary tale about the known (and yet unknown) hazards of using chemical reactions to "clean" our indoor air. 🧵1/
How long and how far do gas molecules and airborne particles travel through indoor air?
It depends on the fundamentals of physics and chemistry, combined with the complexity of buildings. Let's explore a bit... 2/
Inspo from this very nice paper:
nature.com/articles/s4200…
It depends on the fundamentals of physics and chemistry, combined with the complexity of buildings. Let's explore a bit... 2/
Inspo from this very nice paper:
nature.com/articles/s4200…
Some indoor chemicals (like hydroxyl radical) go away really fast - they are doing very rapid transformations to our indoor air quality... not always for the better.
When we "clean" air with reactive chemicals, we unleash a wide range of outcomes to occur 3/
When we "clean" air with reactive chemicals, we unleash a wide range of outcomes to occur 3/
Oxidizers (like hydroxyl) commonly do not improve air quality overall - the chemical transformations due to oxidation often end with making *huge* amounts of airborne particles. The same airborne particles that air cleaners generally seek to remove! 4/ pubs.acs.org/doi/10.1021/ac…
At meter-scale travel distances (seconds-minutes lifetime), particles and gases will float around in a single room. This includes particles up to 10 microns in size, which can harbor viruses and bacteria. This is why we need to #MaskUp, use air #filtration & #ventilation 5/
And with even longer travel distances and lifetimes, there are airborne particles in the "sweet spot" -- these particles around 0.1-1 micron stay airborne for a long time and can work their way between rooms. Particles around 1 micron may also contain virus. 6/
Engineers, chemists, physicists, toxicologists, and building HVAC practitioners (and more!) need to work together, listen to one another, and help people make safe and reliable decisions on how to maintain healthy air indoors. 7/end
If you want to read a bit more about chemically-reactive air cleaners, I wrote a (free to read) scientific article on the subject...
https://twitter.com/EarthMechanic/status/1432821553171947528?s=20
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