Author Comment Last activity Moderation
BostonFern "I also wonder about the material in a HEPA filter. It's supposed to be even more efficient than a surgical mask. But I don't know how breathable ..." | Read more » 5 months ago
BostonFern "I've learned a few more things from my online activities. It was paper towel that the Hong Kong University found to be effective. They took diffe..." | Read more » 5 months ago
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 » 6 months 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 » 6 months ago