Five Key Issues for Assessment of Mass Masking Effects in COVID-19

Covid-19 disease is currently recognized as the most important global crisis. Despite the lack of a definitive treatment for it, it may be possible to prevent its rapid spread by using personal protective equipment. Among of them, the face mask has been introduced more importantly than other ones. Complying with World Health Organization (WHO), the governments follow the mass masking policy. No researches have been comprehensively done about advantages and disadvantages of face mask in various conditions.