▁smoke - free ▁laws ▁have ▁suggested ▁that ▁vent ilation ▁is ▁a ▁means ▁of ▁reducing ▁the ▁harm ful ▁effects ▁of ▁second - hand ▁smoke . ▁A ▁to b acco ▁industry - fund ed ▁study ▁conducted ▁by ▁the ▁School ▁of ▁Technology ▁of ▁the ▁University ▁of ▁G lam organ ▁in ▁Wales , ▁published ▁in ▁the ▁Building ▁Services ▁Journal ▁suggested ▁that ▁" vent ilation ▁is ▁effective ▁in ▁cont rolling ▁the ▁level ▁of ▁cont am ination ", ▁although ▁" vent ilation ▁can ▁only ▁dil ute ▁or ▁partially ▁dis place ▁cont amin ants ▁and ▁occup ational ▁expos ure ▁limits ▁are ▁based ▁on ▁the ▁' as ▁low ▁as ▁reason ably ▁pract ic able ' ▁principle ". C ited ▁at ▁parliament . uk . ▁" CO MM ENT ARY ▁ON ▁ST U DI ES ▁C AR RI ED ▁OUT ▁BY ▁DR ▁AND RE W ▁G E EN S ▁OF ▁THE ▁UN I VER S ITY ▁OF ▁G LA M OR G AN ▁S CH O OL ▁OF ▁TE CH NO LOG Y ". ▁Retrieved ▁ 2 9 ▁December ▁ 2 0 1 1 . ▁ ▁Some ▁hospital ity ▁organis ations ▁have ▁claimed ▁that ▁vent ilation ▁systems ▁could ▁bring ▁ven ues ▁into ▁line ▁with ▁smoke - free ▁restaurant ▁ordin ances . ▁A ▁study ▁published ▁by ▁the ▁American ▁Society ▁of ▁He ating , ▁Re fr iger ating ▁and ▁Air - Condition ing ▁Engine ers ▁and ▁fund ed ▁by ▁the ▁Robert ▁Wood ▁Johnson ▁Foundation ▁found ▁one ▁establishment ▁with ▁lower ▁air ▁quality ▁in ▁the ▁non - sm oking ▁section , ▁due ▁to ▁impro per ly