This topic is only tangentially related to climbing Whitney, but I'm starting a fresh thread to present more recent research related to the effectiveness of face masks and the impact mask wearing can have on reducing community spread of COVID. The previous thread on this topic has become contaminated with misinformation from old and misleading studies, and partisan bickering. Let's keep this thread respectful without the conspiracy nonsense. If you think 92,000 Americans dying in a couple months is a conspiracy, please post elsewhere, you're not interested in science.
I spent considerable time on this topic with an engineering perspective and found a lot of irrelevant old research that needs to be called out. For example, one of those links in the other thread referenced a study based on reuse of the same mask for 30 days by hospital workers in a high-risk environment in Asia. Of course even the N95 masks eventually performed poorly under those circumstances. Many of the studies quoted previously are not new research, they summarize a subset of older studies with a variety of results and methods not suited to the COVID virus. Many of these summary reports complain about a lack of research on the topic, and then strongly conclude, "there's no evidence that masks work." Duh, no relevant research, no evidence.
Here are two recent studies demonstrating cloth masks are effective:
1. Argonne National Laboratory, Center for Nanoscale materials. This study looks at a range of particle sizes relevant to this virus using numerous types of masks from N95, surgical, to several homemade types of various fabrics. https://pubs.acs.org/doi/10.1021/acsnano.0c03252?ref=pdf
2. Northeastern University, this one is so recent its still under peer review. Some of the multi-layer homemade masks with the right fabrics are more than 80% effective, better than surgical masks or commercial dust masks.https://www.medrxiv.org/content/10.1101/2020.04.17.20069567v4.full.pdf