The proper use of masks in the COVID-19 pandemic era: an experimental pilot study

Community mask wearing and personal hand hygiene behaviors are emphasized as among the primary ways to impede the transmission of the coronavirus disease 2019 (COVID-19). However, there is a lack of studies on the efficacy of masks in ensuring safety. This pilot study was designed to investigate the proper use of masks by estimating the changes in temperature and humidity inside masks and examining the bacterial culture of used masks. Two points were set 100 m apart. Two masked participants were made to stand side by side then walk from the first to the second point. When the subjects arrived at the designated destination, we measured the temperature and humidity of each mask and recorded the subjective degree of discomfort on a scale of 10 points. This experiment use the same mask (cotton mask, KF94, anti-droplet mask, dental mask) was repeated ten times. Our results showed that irrespective of the mask used, the inside temperature of a mask was at an average of 2 to 3 degrees higher than the atmospheric temperature, and the humidity inside the mask was twice that on the outside. In all four types of masks investigated, bacterial culture experiments detected similar bacteria found mainly on the skin and mouth for that of the participant. For the walking test, the subjective discomfort was the highest 7.8 ± 1.2 with the anti-droplet mask (p = 0.005). Power walking test, the subjective discomfort was the highest 9.4 ± 0.5 with the KF94 (p = 0.063). Proper mask ventilation is advised, especially in case of subjective discomfort, but only when there is no other person within social distance or while outdoors. For hygienic reasons, discarding a used mask is recommended.

COVID-19; KF94; Mask; Ventilation

[1] Coronaviridae Study Group of the International Committee on Taxonomy of Viruses. The species severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2. Nature Microbiology. 2020; 5: 536–544.

[2] Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, et al. A novel coronavirus from patients with pneumonia in China, 2019. The New England Journal of Medicine. 2020; 382: 727–733.

[3] Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. The Lancet. 2020; 395: 497–506.

[4] Lee S, Kim JM. Coronavirus disease 2019 (COVID-19): pandemic and the challenge of public health. Korean Journal of Family Practice. 2020; 10: 87–95.

[5] Offeddu V, Yung CF, Low MSF, Tam CC. Effectiveness of masks and respirators against respiratory infections in healthcare workers: a systematic review and meta-analysis. Clinical Infectious Diseases. 2017; 65: 1934–1942.

[6] Veronica Dudarev, Miki Kamatani, Yuki Miyazaki, James T Enns, Jun I Kawahara. The attractiveness of masked faces is influenced by race and mask attitudes. Frontiers in Psychology. 2022; 13: 864936.

[7] Desai AN, Mehrotra P. Medical masks. JAMA. 2020; 323: 1517.

[8] Seale H, Dwyer DE, Cowling BJ, Wang Q, Yang P, MacIntyre CR. A review of medical masks and respirators for use during an influenza pandemic. Influenza and other Respiratory Viruses. 2009; 3: 205–206.

[9] Zhou SS, Lukula S, Chiossone C, Nims RW, Suchmann DB, Ijaz MK. Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses. Journal of Thoracic Disease. 2018; 10: 2059–2069.

[10] Rewar S, Mirdha D, Rewar P. Treatment and prevention of pandemic H1N1 influenza. Annals of Global Health. 2015; 81: 645–653.

[11] Wang W, Tang J, Wei F. Updated understanding of the outbreak of 2019 novel coronavirus (2019-nCoV) in Wuhan, China. Journal of Medical Virology. 2020; 92: 441–447.

[12] Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, et al. Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia. The New England Journal of Medicine. 2020; 382: 1199–1207.

[13] Torri E, Sbrogio LG, Rosa ED, Cinquetti S, Francia F, Ferro A. Italian public health response to the COVID-19 pandemic: case report from the field, insights and challenges for the department of prevention. International Journal of Environmental Research and Public Health. 2020; 17: 3666.

[14] Wang F, Zhang C. What to do next to control the 2019-nCoV epidemic? The Lancet. 2020; 395: 391–393.

[15] Hui DS, I Azhar E, Madani TA, Ntoumi F, Kock R, Dar O, et al. The continuing 2019-nCoV epidemic threat of novel coronaviruses to global health—the latest 2019 novel coronavirus outbreak in Wuhan, China. International Journal of Infectious Diseases. 2020; 91: 264–266.

[16] Li G, De Clercq E. Therapeutic options for the 2019 novel coronavirus (2019-nCoV). Nature Reviews Drug Discovery. 2020; 19: 149–150.

[17] Menendez R. Risk factors of treatment failure in community acquired pneumonia: implications for disease outcome. Thorax. 2004; 59: 960–965.

[18] Jayaweera M, Perera H, Gunawardana B, Manatunge J. Transmission of COVID-19 virus by droplets and aerosols: a critical review on the unresolved dichotomy. Environmental Research. 2020; 188: 109819.

[19] Cork R, Isaac I, Elsharydah A, Saleemi S, Zavisca F, Alexander L. A comparison of the verbal rating scale and the visual analog scale for pain assessment. The Internet Journal of Anesthesiology. 2003; 8.

[20] Ko JY, Yoon SH, Kim BS. Influence of long-term power walking on obese people’s cardioactive capacity and blood lipids. Journal of Sport and Leisure Studies. 2007; 31: 843–852.