Author Comment Last activity Moderation
BostonFern "On the net, I've seen studies about using different material to filter air. Based on my impression, cotton is not an effective media to filter v..." | Read more » about 4 years ago
BostonFern "I have a few scientific paper to share with you. This paper says that salt can be used to inactivate virus on surgical mask." | Read more » about 4 years ago