Cherrie, John W. and Apsley, Andrew and Cowie, Hilary and Steinle, Susanne and Mueller, William and Lin, Chun and Horwell, Claire J. and Sleeuwenhoek, Anne and Loh, Miranda (2018) 'Effectiveness of face masks used to protect Beijing residents against particulate air pollution.', Occupational and environmental medicine., 75 (6). pp. 446-452.
Objectives Many residents in Beijing use disposable face masks in an attempt to protect their health from high particulate matter (PM) concentrations. Retail masks may be certified to local or international standards, but their real-life performance may not confer the exposure reduction potential that is marketed. This study aimed to evaluate the effectiveness of a range of face masks that are commercially available in China. Methods Nine masks claiming protection against fine PM (PM2.5) were purchased from consumer outlets in Beijing. The masks’ filtration efficiency was tested by drawing airborne diesel exhaust through a section of the material and measuring the PM2.5 and black carbon (BC) concentrations upstream and downstream of the filtering medium. Four masks were selected for testing on volunteers. Volunteers were exposed to diesel exhaust inside an experimental chamber while performing sedentary tasks and active tasks. BC concentrations were continuously monitored inside and outside the mask. Results The mean per cent penetration for each mask material ranged from 0.26% to 29%, depending on the flow rate and mask material. In the volunteer tests, the average total inward leakage (TIL) of BC ranged from 3% to 68% in the sedentary tests and from 7% to 66% in the active tests. Only one mask type tested showed an average TIL of less than 10%, under both test conditions. Conclusions Many commercially available face masks may not provide adequate protection, primarily due to poor facial fit. Our results indicate that further attention should be given to mask design and providing evidence-based guidance to consumers.
|Full text:||(VoR) Version of Record|
Available under License - Creative Commons Attribution.
Download PDF (1055Kb)
|Publisher Web site:||https://doi.org/10.1136/oemed-2017-104765|
|Publisher statement:||This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/|
|Date accepted:||12 March 2018|
|Date deposited:||14 June 2018|
|Date of first online publication:||09 April 2018|
|Date first made open access:||14 June 2018|
Save or Share this output
|Look up in GoogleScholar|