gap in the market maybe?
by Rhiannon on Jun.20, 2009, under Rhiannon Davies
As I held my breath past the fourth or so bus spewing out grey clouds on my ride to work the other day, I had a flash of inspiration … helmet chinbar vents fitted with miniature air filters (and maybe freshners)! Well why not, if you can have helmets fitted with sunnies? 
1 comment for this entry:
June 22nd, 2009 on 4:06 pm
They already exist. They’re called foggy’s and they help prevent the visor fogging up on the inside but also filter the air coming through the vents:
http://cgi.ebay.co.uk/Respro-Foggy-Anti-Fog-Helmet-Mask-%2f-Breathguard—Black_W0QQitemZ120344650205QQcmdZViewItem