The human body is near 37C / 99F and ambient room temperature is typically kept near 22 C / 70 F. Humans are constantly shedding skin dust, which due to their higher temperature are always floating around rooms. Additionally, people are constantly spreading tiny aerosolized particles from their lungs, even without coughing, simply by talking and breathing. For example:

https://www.science.org/doi/10.1126/science.abd9149

"Airborne transmission of respiratory viruses" (2021) Science

> "Advances in aerosol measurement techniques, such as aerodynamic and scanning mobility particle sizing, have shown that the majority of exhaled aerosols are smaller than 5 μm, and a large fraction are <1 μm for most respiratory activities, including those produced during breathing, talking, and coughing."

Such droplets can likely pass through cloth masks with little difficulty, and 6 feet of distance is probably irrelevant. The only thing that prevents transmission and infection between nearby people is containment efforts such as BSL-3/4 laboratory precautions and even there, accidental transmission has been documented.

Without highly strict quarantine and isolation protocols, we're really all just swimming in the same petri dish when it comes to respiratory transmission.