In article ,
Harvey Van Sickle wrote:

    > On Wed, 30 Apr 2003 15:11:43 GMT, wrote
    >
    > >
    > > "A.Malhotra" wrote in message
    > > news:[email protected]...
    > > ...
    > >> The funny thing is, wearing a face mask is ABSOLUTELY USELESS as
    > > protection
    > >> against SARS!
    >
    > -snip-
    >
    > > The theory is that the virus is carried in exhaled water droplets,
    > > which are large enough to be trapped by a mask, although it is by
    > > no means clear that exhalation is a mode of transmission, much
    > > less whether it is the primary mode of transmission.
    >
    > Connected with this is that surgical masks are intended to keep
    > infection *in*, not to exclude it: they're worn by those who are at
    > risk of infecting other people rather than by uninfected people as a
    > means of protection. (It's like in an operating theatre: the medical
    > staff wear masks to protect the patient from being infected, not to
    > protect themselves from inhaling stuff.....)



they are also worn by anyone working with people with TB or other
infectious diseases -- for personal protection -- and they tend to work
fairly well for that

In article , [email protected]
wrote:

    > In article ,
    > jem*NO-SPAM*@netspace.net.au (Joan McGalliard) wrote:
    >
    > > A.Malhotra wrote:
    > >
    > > > The funny thing is, wearing a face mask is ABSOLUTELY USELESS as
    > > > protection
    > > > against SARS! Its a virus.... ie VERY VERY small.....I'm really
    > > > amazed that
    > > > I only heard a doctor point this out for the first time on Radio 4's
    > > > pm
    > > > program yesterday!
    > >
    > > I'm not a doctor (as I'm about to prove) but I wonder if this is
    > > correct. The virus is carried in aerosol spray from sneezing and
    > > coughing, the masks block the aerosol spray. Surely that must reduce
    > > viral transmission.
    >
    > Neither am I a doctor, but -- aerosol seems to be, at worst, a minor means
    > of transmission. The danger is that people will think they are safe
    > because they are wearing a mask, and thus ignore other, more likely
    > potential sources of transmission.



most of the major spread has been aerosol specifically medical personal
breathing aerosol from machines designed to help patients breath

Harvey Van Sickle wrote:
    >
    >
    > Connected with this is that surgical masks are intended to keep
    > infection *in*, not to exclude it: they're worn by those who are at
    > risk of infecting other people rather than by uninfected people as a
    > means of protection. (It's like in an operating theatre: the medical
    > staff wear masks to protect the patient from being infected, not to
    > protect themselves from inhaling stuff.....)

But when are mobs logical? (And with something like SARS, people's
reactions to their perceived peril are mob-like.)


    >
    > --
    > Cheers,
    > Harvey
    >
    > For e-mail, harvey becomes whhvs.