Assessing Human Nanoparticle Generation During Exercise Using Condensation Particle Counting Technology
Previous research into human-generated aerosols has clearly shown that normal breathing and talking results in exhaled sub-micron particles that can lead to the airborne spread of viruses. However, due to measurement difficulties, there is a critical gap in the literature about which physical activities generate significant levels of nanoparticle emissions, which makes it difficult for public health officials to determine which environments pose the greatest risk for the airborne transmission of viruses. In this study, we use a cutting-edge condensation particle counting device (created by TSI, Inc.) to measure nanoparticle emissions during four exercise activities: cycling, jogging, weight-lifting, and talking. For each experiment, the activity was completed at various levels of exertion, as measured by the device’s differential pressure monitor and various other exertion level measures as dictated by the activity, in order to understand whether there is a correlation between a subject’s exertion level and the rate of nano-particles emitted. The experiments showed that the sub-micron particle generation rate for cycling, lifting, and running at maximum effort was roughly five times greater than the baseline rate (subject at rest), indicating that there is in fact a correlation between exertion level and nano-particle generation. Furthermore, the study showed that the particle generation rate for loud talking was roughly 100x greater than the baseline rate. It is our expectation that this will serve as a basis for further research aimed at identifying the activities that are most likely to lead to high levels of nanoparticle generation in a range of settings.