2-Layer Cotton Masks Better than Surgical!
Scientists at the National Institute of Standards and Technology (NIST) and the Smithsonian's Museum Conservation Institute conducted research to mimic real-world conditions when we breathe into our masks, as opposed to previous experiments that were conducted in dry air.(1) They found that when cotton was humidified, like when we breathe into our masks, the filtration efficiency of 100 percent woven cotton increased from 12 percent to 45 percent. Christopher Zangmeister, the scientist at NIST who led the study, said that the scientists were surprised. Synthetic fabrics, and even poly-cotton blends, repel water and don't absorb as well as cotton, so their filtration properties did not rise with humidity.
“When you exhale into a simple cotton mask, one that’s two layers, it works at least as well as a single-layer surgical mask,” he says. “It may even be better.” says Zangmeister.
Surgical masks are made of plastic and are becoming a huge nuisance to our environment, polluting our streets and oceans, filling up landfills, and injuring and killing wildlife animals. Researchers estimate that at the height of the pandemic, nearly 200 billion masks were being used across the globe each month. (2) And they cannot be recycled or re-used.
Environmentalists are pushing that people use reusable fabric masks as everyday masks. Now there is no excuse not to.
(1) The Washington Post, Science section "What's Inside All Those Masks?", March 27, 2021
(2) CBS8, "Environmental concerns rise over impact of single-use disposable masks during pandemic" March 26, 2021