Abstract: An air filtration unit of the type having a liquid filtration medium in a canister with air entering below the level of the liquid, bubbling up into an upper air chamber and thence conducted to a face mask, is simplified for use not only in sedentary occupations but so that it can be used by workmen in strenuous occupations requiring leaning over, lying down, etc. One way valves assure that only scrubbed air enters the face mask, the mask is peripherally sealed and float, or gravity, valves prevent leakage into the mask, or out of the canister, when the unit is in abnormal position. In non-portable form, air filtration masks, peripherally sealed on the wearer's face have a common air chamber with air drawn thereinto from outisde the pollution environment.