Models with a noise level as low as 20 to 30 dB are often made for bathrooms, small bedrooms, or even traveling as they emit very little sound (as much as a muffled hum)
Equipped with a range of features that make it uniquely portable, its hard to find a better enthusiast-grade portable air quality monitor than this
Reference Sources Research on the Design of Automation System of Distribution and Packaging of Cigarettes: Explores the design and automation of cigarette packaging systems, including plastic-envelope machines
Colorado tells a similar story in slower motion
Overall, the results, even if only acute effects after a single use were investigated in this work, point in a comparable direction, as preliminary studies have already shown 65,65,67