Ive recently been thinking of ways to make it more pleasant to ride in the city. Also reading the book "choked" has woken me up to the very real dangers of breathing air polution all the time. Perhaps also recumbents are a little worse off as they are closer to exhaust pipes.

A normal filter mask like respro/ toto bobo  might reduce particulates but is uncomfortable/sweaty/ moist, restricts air flow and hard to get a good seal and can irritate the skin and leave marks. So i was thinking about how to use something like a 3m versaflow (or an ebay china made one for 1/5 the price)  to direct filtered air over the face, but without wearing the full face mask/face shield thing. The bigger  3m filters would more effectively reduce gasses too hopefully.

I hear a significant proportion of profesional cyclists develop asthma due to the vast amount of air they get through and the pollen, dust, fumes etc in that air.

Or how about mounting a battery powered unit in a hard box or tail fairing  on the rear of the seat  on a recumbent bike and then using a snorkel type mouth piece and pipe to suck filtered air from there?

It might be usefull to find somewhere to get a one way vent valve for the pipe for better exhale. Anyone know where to get something like that?

Any other ideas on what might work or how to do this well?