ZT: which masks are the least effective

https://amp.cnn.com/cnn/2020/08/08/us/duke-university-face-mask-test-trnd/index.html

The most effective mask was the fitted N95. Three-layer surgical masks and cotton masks, which many people have been making at home, also performed well.

Neck fleeces, also called gaiter masks and often used by runners, were the least effective. In fact, wearing a fleece mask resulted in a higher number of respiratory droplets because the material seemed to break down larger droplets into smaller particles that are more easily carried away with air.

Folded bandanas and knitted masks also performed poorly and did not offer much protection.

"We were extremely surprised to find that the number of particles measured with the fleece actually exceeded the number of particles measured without wearing any mask," Fischer said. "We want to emphasize that we really encourage people to wear masks, but we want them to wear masks that actually work."

 

所有跟帖： 

• 感謝總結。這個測驗沒提KN95口罩。另外，N95口罩裏也分工業性的和醫用的。貌似不管三七二十一，隻要是N95就是第一有效。 -香草仙子- ♀ (0 bytes) () 08/09/2020 postreply 20:08:11

• KN95是中國製式口罩，市麵上出售的質量難說。 -pickshell- ♀ (0 bytes) () 08/10/2020 postreply 08:44:39

• 我看到FDA 官網有什麽Appendix A 之類， 不知道這些中國的kn95 口罩靠不靠譜。不知道 FDA 咋個操作法， -Shanghaigirl98- ♀ (449 bytes) () 08/10/2020 postreply 11:39:39

• 看您說，我去FDA網上，有關Appendix A口罩列表有一段說明可看下。。 -pickshell- ♀ (1062 bytes) () 08/10/2020 postreply 13:56:43

• 從四月開始，我們係統醫院裏的一線醫護都一直使用“N-100”Mask，每三十天換Filters（Half face respir -老道- ♂ (0 bytes) () 08/10/2020 postreply 05:54:26

• 效果？ -欲千北- ♂ (0 bytes) () 08/10/2020 postreply 07:25:04

• 無法評價。這種效果隻能通過有對照組的大數據才能評價。我知道的醫護人員的感染率很低，但我這不是 -老道- ♂ (294 bytes) () 08/10/2020 postreply 08:19:22

• 多謝。印象中一線醫護人員帶口罩後感染率很低。 -欲千北- ♂ (0 bytes) () 08/10/2020 postreply 08:33:15

• 和你的感覺一樣。在能保證PPE的前提下，醫護隻要注意保護自己，在工作中感染的機會很小（隻是在目前情況下）。 -老道- ♂ (0 bytes) () 08/10/2020 postreply 08:43:16