the effect of face mask, air temperature, and humidity on covid-19 transmission: a systematic review and meta-analysis

Context: at the beginning of the covid-19 pandemic, the effects of personal protective equipment (ppe) such as face masks, as well as environmental conditions, including temperature and humidity changes, were discussed due to the lack of effective medicine. methods: the preferred reporting items for systematic reviews and meta-analysis (prisma) were implemented to conduct the present systematic review. the articles were selected from papers published by may 2020 in pubmed, web of science, science direct, scopus, and google scholar databases. this meta-analysis estimated relative risk (rr) and pooled mean depicted as effect size (es) using the random or fixed effects methods. results: ten studies met inclusion criteria, four of which addressed the effect of face masks and six of which dealt with temperature and humidity changes. this eta-analysis study showed that wearing face masks against the covid-19 virus had a remarkable safety impact with rr (%95 ci) 8.56 (2.10 - 34.90), (i 2= %0.0 p = 0.999), and the pooled mean changes in temperature and humidity were estimated to be with es (%95 ci) 9.03 (4.32 - 13.74), (i 2= %99.7, p < 0.0001) and with es (%95 ci) 56.82 (46.12 - 67.51), ( i 2= %99.3, p < 0.0001) during the outbreak of the covid-19. conclusions: the findings of this systematic review and meta-analysis illustrate the effectiveness of face masks, in general, in preventing the transmission of the covid-19 virus. according to the findings, temperature and humidity changes do not increase the outbreak of the covid-19 virus.