In-mask temperature and humidity can validate respirator wear-time and indicate lung health status

John W. Cherrie, Shuohui Wang, William Mueller, Charlotte Wendelboe-Nelson, Miranda Loh

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)
45 Downloads (Pure)


The effectiveness of respiratory protection is dependent on many factors, including the duration and times during the day when it is worn. To date, these factors could only be assessed by direct observation of the respirator user. We describe the novel use of a data-logging temperature and humidity sensor (iButton Hygrochron) located inside a facemask to quantify respirator wear-time through supervised experiments (Phase 1) and an unsupervised wearing trial (Phase 2). Additionally, in Phase 1 the in-mask temperature was compared with measurements of exhaled breath temperature. We found humidity responds more rapidly than temperature to donning a mask, so it was considered a more sensitive measure of wear-time, particularly for short durations. Supervised tests showed that this method can provide accurate and precise estimates of wear-time, although the approach may be unsuitable for use in situations where there is high ambient humidity. In-mask temperature is closely associated with exhaled breath temperature, which is linked to lung inflammation. This technique could provide a useful way of evaluating the effectiveness of respirators in protecting health in real-life situations.

Original languageEnglish
Pages (from-to)578–583
Number of pages6
JournalJournal of Exposure Science and Environmental Epidemiology
Early online date31 Oct 2018
Publication statusPublished - Jul 2019


Dive into the research topics of 'In-mask temperature and humidity can validate respirator wear-time and indicate lung health status'. Together they form a unique fingerprint.

Cite this