WASHINGTON, Sep 10 (PTI) Cloth masks can be effective for up to a year, as repeated washing and drying does not reduce their ability to filter out infection-carrying particles. It is said in one study. The research, published in the journal ‘Aerosol and Air Quality Research’, also confirms previous studies showing that applying a cotton cloth mask over a surgical mask provides greater protection than a cloth mask. The study’s lead author, Marina Vance, an assistant professor at the University of Colorado Boulder in the US, said that in terms of environmental
The researchers said that an estimated 7,200 tonnes of medical waste has been generated every day since the start of the Kovid-19 pandemic, including disposable masks. Vance said, “We were disturbed to see masks thrown around while going out since the start of the epidemic.”
The researchers created two-layers of cotton, tested them through repeated washing and drying for a year, and tested them about every seven cleaning times. Researchers tested the effectiveness of the mask in different ways. The cotton fibers began to break after repeated washing and drying, but the researchers found that this did not significantly affect the fabric’s ability to filter fine particles. However, it was seen in the study that after some time it became difficult to breathe with such masks.
The study found that cotton cloth masks were able to filter out up to 23 percent of the microscopic particulates of 0.3 microns. By applying a cotton cloth mask over the surgical mask, the filtration efficiency increased to 40 percent. The KN-95 and N-95 masks performed best at filtering out 83-99 percent of these fine particles, the researchers said.