Originally Posted by
tpelle
Good discussion.
Someone mention SCBA earlier.
I'm retired from the fire department, and so have a lot of experience with SCBA (Self Contained Breathing Apparatus). These are the units that are somewhat similar to the scuba gear that divers wear. Basically there are two types found in general use - demand units (no longer sold), and pressure-demand units...
Look at the pictures of the Chinese riding around on their cruisers, though, wearing those paper surgical masks.
tpelle,
SCBAs are for environments "Immediately Dangerous to Life and Health," also known as IDLH. They really are not appropriate for bicycle use, as you probably know.
Concerning surgical masks, they are actually not respiratory protection. Their function is to keep surgeons and other medical personnel from contaminating a surgical site (keeping contamination in, rather than pollution out). They may make some feel good about wearing them for pollution, but because they don't make a seal around the face, they really do not work well for things like diesel exhaust nanoparticles.
John