David Mikeska comments

Those masks are useless for the application of biological protection. Only a full face mask that covers and protects the eyes and the airspace between the mask and the person isolated with a canister type filter is the only type that works. The best filter is an nbc-77. But the bio load of pathogens in the air will be mostly from those ear loop mask propagating them after the moisture level in the mask achieves a certain level. Causing the mask to culture new pathogen growth and releases in the air as the person moves. I am the pandemic response expert in the United States up to 2005, and this and other issues I must address, in the US with my former colleagues. But Dr. Fukushima over there should have insisted on wearing visors. Which would be a minimum protection for about an hour, but a sealed full face mask with a filter air supply is optimal for hours of use. The ear loop mak is only a dust mask and its only valid for that application for 30 minutes. Any longer, can cause respiratory illnesses. This is why I am pushing for a ban in them in the US for anything other than using it as a dust mask.