Aerosols. Masks are an efficient and low cost intervention for limiting such transmissions. Here's a review of 67 randomised controlled studies concluding that.

Aerosols. Masks are an efficient and low cost intervention for limiting such transmissions. Here's a review of 67 randomised controlled studies concluding that. https://www.cochrane.org/CD006207/ARI_physical-interventions-to-interrupt-or-reduce-the-spread-of-respiratory-viruses https://www.cochrane.org/CD006207/ARI_physical-interventions... Is it ok to close the barn door now?