[*BCM*] Filter Masks

[Greg Howard]

> A mask like this won't filter out any of the toxic gases that motor vehicles
> produce but it will take care of the particulates.

I don't know the mask details, but I believe that the simpler and
cheaper masks tend to filter the bigger particles -- whereas the
smaller ones are much more toxic.  Filtering dust-sized particles is
not a bad idea, but to be effective against car exhaust I think you'd
want something that filtered small stuff, i.e. PM2.5 (less than 2.5
microns) or even PM1 (under a micron).  I would assume that dust masks
are essentially ineffectual against those.

Ozone is probably as big an issue, and won't be addressed by masks.
All in all, I doubt it's worth it, except in certain conditions (e.g.,
pollen and allergies).


greg


On 6/11/07, Jim Leonard <jim_bcm at xuth.net> wrote:
> On Sun, Jun 10, 2007 at 04:47:43PM -0600, list at moz.geek.nz wrote:
> > Ben said:
> > > I've used HEPA filter masks and they're no fun to wear.  They get sweaty
> > > and you have to exert extra effort to force your incoming air through
> > > the filters.
> >
> > I use the bike shop filter masks most of the time because I notice a
> > difference when I don't - the traffic smells noticably worse and my
> > throat is more aggravated after my commute. That may be a purely
> > cosmetic difference, but it's enough to make me happy. It also means
> > I notice smokers less while I'm riding which is a pleasant benefit.
>
> A mask like this won't filter out any of the toxic gases that motor vehicles
> produce but it will take care of the particulates.  Specifically you will
> be filtering out the soot from the vehicle exhaust along with pollen and
> road dust.  This is also while you're breathing heavily from exertion so
> you'll be pulling more of it into your lungs.
>
> > Of course, while I'm actually wearing the mask all I really notice is
> > that my breathing is obstructed.
>
> I wonder how hard it would be to find a positive pressure filtering system.
> That could be relatively comfortable to wear but I don't know where I'd
> find such a thing.
>
> --jim
>
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