Charlesaf3 said:
I wonder how well surgical masks would work - anyone tried them?
Surgical masks are effective at keeping healthcare staff from spitting into the operating field. They probably catch very large dust particles too, the type that your normal nasal passages would trap anyway. Surgical masks are pretty useless against any type of particle smaller than a fine water mist however.
For user protective purposes (as compared to preventing contamination of the surgical field) surgical masks are helpful only to prevent spread of infectious diseases that are spread by large droplets. Strep, staph and the common cold type pathogens that are most typically spread by contact rather than by air. Essentially, surgical masks are good at stopping spit in both directions. They are very difficult to fit well as they typically have only one elastic and simply cannot be held to your face well enough to create a seal. As such, lots of air you breathe while wearing a surgical mask actually comes around the edges of the mask and is never filtered. Still, to minimize breathing big dust particles and some pollen they would likely be better than nothing.
For infectious agents, fine pollen and potentially toxic dust particles that are spread as very small particles too small to see with the naked eye (droplet nuclei is the technical term), the surgical masks are useless even if they fit properly. The filter media is simply not fine enough to trap tiny particles. Unfortunately, those are exactly the particles that can make it past your bodies own nasal passage filter mechanisms so these are the ones that make it directly to your lung.
Disposable N95s are the next step up in protection and you can get them at Home Depot etc. N95 masks, properly fitted, are appropriate for short term protection against small dust particles and infectious agents that spread through the air (Tuberculosis, chickenpox, measles) but as has been noted previously in this thread, the paper N95s are pretty uncomfortable to wear for long or when you are doing more work than just sitting or standing. If it isn't uncomfortable to wear it probably is not fitted properly and is too loose. The type of exhaust valve Soundguy mentioned helps prevent fogging of glasses and helps exhaling but you still need to draw your breath through the filter media to be effective and that means you are breathing against resistance which is never particularly comfortable. As the masks get saturated with moisture from breathing, they become even more difficult to breath though and paper N95s should usually be changed every 30 minutes or so. (Note: N95s are reusable you just need to let them dry out so you could rotate two or three and they would last many uses).
If someone is really serious about long term (hours) protection you really need to think about either powered respirators (where the motor is pulling air through the filter for you) or at least the multi cartridge passive respirators where you have a larger surface area of filter media. I don't have any experience with the multi cartridge units but the powered respirators are comfortable and very easy to work in so long as you don't mind looking like a space cadet.
