RESUMO
BACKGROUND: To limit the spread of the new coronavirus disease 2019 (COVID-19), the World Health Organization recommends the use of face mask as a part of the pandemic control strategy. It has published also "best practices" in which it advises to avoid touching the mask while wearing it. This might be challenging. The purpose of this study was to investigate the frequency of mask-touching behavior in public transportation. METHODS: Observational study using data collected in real life. This survey was conducted in subways and local trains of the greater Paris region, France, between May 4th and 25th, 2020. Public Transportation users were covertly observed. Demographic characteristics, type of mask and the main activity were collected by the investigator. The duration of observation, the frequency of touching face mask, hair and the uncovered area of the face were also recorded. Frequency of mask-touching per hour was determined. RESULTS: One hundred eighty two persons were observed. The median of estimated age [1st and 3rd interquartile] was 35 [30;45] years and 87 (48%) were women. One hundred forty three (79%) were wearing surgical mask. The median time of observation was 8 [4;12] minutes. During this period, 87 (48%) persons touched their mask 15 [7.5;30] times per hour of whom only two (8%) have used hydroalcoholic solution to disinfect their hands. CONCLUSIONS: Mask touching is frequent and is rarely followed by hand disinfection. Actions regarding mask use should be taken to improve compliance.