Effectiveness of face masks used to protect Beijing residents against particulate air pollution
John W Cherrie, Andrew Apsley, Hilary Cowie, Susanne Steinle, William Mueller, Chun Lin, Claire J Horwell, Anne Sleeuwenhoek, Miranda Loh
Occupational and Environmental Medicine Jun 2018, 75 (6) 446-452; DOI: 10.1136/oemed-2017-104765