With the new coronaviruss infection of pneumonia pandemic prevention and control work intensifying, N95 masks, KN95 masks, FFP2 masks, and other professional names have brought mask standards to the public’s attention. Comparing the standards of the United States, China, Europe, Korea, Japan, Australia, etc., this paper focuses on the filtration efficiency of ordinary masks and […]
Tag Archives: health
Some parents believe that compulsory wearing masks in school is harmful to children’s mental health, but according to experts, the evidence is just the opposite. Gilbert said that the most significant negative impact of the epidemic on children’s mental health occurred in the period before the epidemic. At that time, the children who received distance […]