No, but the reality of 1-way masking is exactly why Iβve always incorporated other viral load-lowering mitigations into my precautions: routine Nuvaxovid, nasal sprays and oral products like lozenges/mouthwash, and support of the innate immune system through diet and supplementation.
Of course, I wasnβt doing all of that until 2022/2023, but cases were lower before then and other people were largely still masking.
Since starting, however, I took dozens of greyhound bus trips, all ~6-8 hours, in 2022-2024 (long distance relationship), and never ended up with an infection. Never any masks on anybody else. Thatβs one of the absolute worst one-way masking situations that I can think of, since thereβa no ventilation or air filtration whatsoever, unlike a plane or most trains. I never even bothered to test the CO2 levels despite owning a monitor, because I really didnβt want to see the number and itβs not like I was going to be able to do anything about it anyway. I assume it was always many thousands, though