Cerebral and systemic physiological effects of wearing face masks in young adults

Proc Natl Acad Sci U S A. 2021 Oct 12;118(41):e2109111118. doi: 10.1073/pnas.2109111118.


The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.

Keywords: COVID-19; cerebral hemodynamics; face masks; near-infrared spectroscopy; systemic physiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living
  • Adult
  • Brain / blood supply
  • Brain / metabolism
  • Brain / physiology*
  • COVID-19 / prevention & control
  • Female
  • Healthy Volunteers
  • Hemodynamics
  • Humans
  • Male
  • Masks*
  • Microcirculation
  • Monitoring, Physiologic
  • Oxygen / metabolism
  • SARS-CoV-2
  • Spectroscopy, Near-Infrared
  • Young Adult


  • Oxygen