The BMJ
“….Moreover the WHO stated in their report of June 5 “At present, there is no direct evidence (from studies on Covid19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including Covid19 [10] Contamination of the upper respiratory tract by viruses and bacteria on the outside of medical face masks has been detected in several hospitals [11]. Another research shows that a moist mask is a breeding ground for (antibiotic resistant) bacteria and fungi, which can undermine mucosal viral immunity. This research advocates the use of medical / surgical masks (instead of homemade cotton masks) that are used once and replaced after a few hours [12]. This means that a family with 2 children and 2 parents who go to work by public transport and do their shopping will consume 20 facemasks per day (€ 25 / day, € 9,000 / year per family).”