# 2129
Our understanding of how well different types of masks might work in a pandemic is incomplete, although evolving. Frankly, this has been an area of research where, up until recently, not a lot of work has been done.
While I've long opined that `any mask has to beat no mask at all' (see Any Mask In A Viral Storm), up until now, there really hasn't been a lot of solid scientific research to support that notion.
In fact, some scientists have felt that anything less than a fit tested N95 (or equivalent) mask was pretty much a waste of time against a viral pathogen like influenza.
Today, in a study published in PLoS ONE (Public Library of Science), we get research that indicates that even home-made masks can help reduce exposure to respiratory infections.
A Hat tip to Nimbus on the Wiki for posting this link.
Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population
Marianne van der Sande1*, Peter Teunis1,2, Rob Sabel3
1 National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands2 Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America3 Netherlands Organisation for Applied Scientific Research (TNO), Rijswijk, Netherlands
Citation: van der Sande M, Teunis P, Sabel R (2008) Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population. PLoS ONE 3(7): e2618. doi:10.1371/journal.pone.0002618
Abstract
Background
Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances.
Methodology
We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient.
Principal Findings
All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers).
Conclusions/Significance
Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission.
Figure 1. Protection factor of home-made mask being measured by Portacount in volunteer.
Volunteer with home-made mask made of tea cloth. Note the candles in the foreground and the other mask types in the background.
The methodology of this study is interesting, and is well described in the article. Those interested will probably want to read the entire study.
While surgical and home made masks afforded some level of protection in these experiments, they did so at much lower levels than the N95 or (FFP)-2 masks.
Health Care workers, or anyone in close, direct contact with infected individuals will certainly want the protection of an N95 (or equivalent) mask.
For `casual wear' for the general public during a pandemic, however, this study provides some evidence that surgical and home-made masks would be at least partially protective against infection.
No one is suggesting that any type of mask will make it absolutely `safe' to go out in a pandemic. But a mask can make it `safer'.
It can help reduce the risks.
And during a pandemic, when the supply of N95 and surgical masks may not be enough to meet the demand, the news that home-made masks can afford at least some protection is welcome, indeed.
An example of one type of home-made mask (not the one tested above, however) appeared in the CDC's Journal of Emerging Infectious Diseases in 2006.
Suggested citation for this article:
Dato VM, Hostler D, Hahn ME. Simple respiratory mask [letter]. Emerg Infect Dis [serial on the Internet]. 2006 Jun [date cited]. Available from http://www.cdc.gov/ncidod/EID/vol12no06/05-1468.htm
