01412nam a22001937a 4500 D0001C000048 DOH 20201120141918.0 201120b ||||| |||| 00| 0 eng d Quesnel, Louis B. The efficiency of surgical masks of varying design and composition / Louis B. Quesnel Five different types of surgical mask of varying design and composition of natural and synthetic fibres were tested for their efficiency in vivo by means of a special test chamber. Contaminated particles escaping through or around the mask during speech by the wearer could be collected and sized. Analysis of the data showed that the gross efficiency of all the masks was high, but that some masks were distinctly better at small particle 'filtration' than others. There was a significant difference in efficiency between the best and worst masks. The best masks contained more fabric, were softer and were pleated, while the worst were stiffer, smaller and not pleated. Reusable cotton fabric masks were as effective as synthetic fabric masks when made to a good design. In: British Journal of Surgery 1975 vol. 62 (12) pages: 936–940. Air Microbiology Bacteria isolation and purification Masks standards https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7161878/pdf/BJS-62-936.pdf CV 1782 1782 0 0 0 0 DOHCL DOHCL ElectronicRes 2020-11-20 0 COVID-19-000048 D0001C000048 2020-11-20 00:00:00 2020-11-20 CV