Characterizing Particulate Generation During Cardiopulmonary Rehabilitation Classes With Patients Wearing Procedural Masks

Scott A. Helgeson, Bryan J. Taylor, Kaiser G. Lim, Augustine S. Lee, Alexander S. Niven, Neal M. Patel

Research output: Contribution to journalArticlepeer-review


Background: The clinical benefits of cardiopulmonary rehabilitation are extensive, including improvements in health-related quality of life, emotional condition, physical function, and overall mortality. The COVID-19 pandemic continues to have a negative impact on center-based cardiopulmonary rehabilitation. Justifiable concern exists that the exercise-related increase in pulmonary ventilation within the rehabilitation classes may lead to the generation of infectious respiratory particles. Research Question: Is cardiopulmonary rehabilitation while wearing a procedural mask a particle-generating procedure? Study Design and Methods: Data were collected prospectively at a cardiopulmonary rehabilitation facility with all patients wearing a procedural mask. Small (0.3-4.9 μm) and large (5-10 μm) particle generation was quantified using a light-scattering particle counter. Data were analyzed by time, exertion level, and number of participants. Results: A total of 24 distinct patients attended two or more of the cardiopulmonary rehabilitation classes tested. Most of the patients were men (n = 16 [67%]) and were in rehabilitation because of cardiac disease. During the cardiopulmonary rehabilitation class, small and large micrometer-size particles increased with increasing class size. In classes with four patients or more, a significant increase was found from ambient levels in both small (four patients, P < .01; and five patients, P < .01) and large (four patients, P < .01; and five patients, P < .01) particle count that peaked at about 35 to 40 min during each class. Interpretation: Using an airborne particle counter, we found significant exercise-related increases in both small and large micrometer-size particle generation during cardiopulmonary rehabilitation classes, with larger class sizes (ie, more patients), despite participants wearing a procedural mask.

Original languageEnglish (US)
Pages (from-to)633-641
Number of pages9
Issue number2
StatePublished - Aug 2021


  • aerosol
  • cardiopulmonary rehabilitation
  • coronavirus
  • particle generation
  • particle measurement

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine
  • Cardiology and Cardiovascular Medicine


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