>Different virus sizes, different mask effectiveness. Not necessarily - when speaking and otherwise spreading aerosols they start out much larger than any viru

>Different virus sizes, different mask effectiveness. Not necessarily - when speaking and otherwise spreading aerosols they start out much larger than any virus particles contained within them and quickly dry out and shrink if in air (i.e. not caught in a mask) [1, 1um - 500um, between Table I & Fig 11]. If they were on their own, the small 'nanoparticle' regime (1-100nm) shows fairly good filtration in a variety of media [1st image in 3] thanks at least in part to the diffusion of particles through filter media. It's not the same by size by any means (with smaller often being the most passed particle size) but it varies with filter construction and treatment [3]. [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8061903/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8061903/ [2]: https://www.tandfonline.com/doi/pdf/10.1080/00022470.1980.10464592 https://www.tandfonline.com/doi/pdf/10.1080/00022470.1980.10... [3]: https://academic.oup.com/annweh/article/56/5/568/159920 https://academic.oup.com/annweh/article/56/5/568/159920