Cloth (e.g. cotton or gauze) masks are not recommended
under any circumstances.
クロス(例えば綿やガーゼ)マスクはお勧めしません。
どんな状況でも。
出典:Advice on the use of masks in the community, during home care and in healthcare settings in the context of the novel coronavirus (COVID-19) outbreak
https://www.who.int/publications-detail/advice-on-the-use-of-masks-the-community-during-home-care-and-in-health-care-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak