They identified a few major areas of accelerated aging in the faces of the smoking twins: The smokers' upper eyelids drooped while the lower lids sagged, and they had more wrinkles around the mouth
The microscopic particles from cigarette smoke cling to the fibers in these materials, embedding themselves far below the surface
Special enzymes actually remove odors form the Air - Not just cover them up
In another recent Criterion reissue, Only Angels Have Wings , one of my favourite minutes in the film (any film, really) features Jean Arthur and Cary Grant leading the cantina band in Some of These Days and The Peanut Vendor Song
Adverse events were graded according to the severity of the symptoms/signs using a 3-point scale, 1 = mild (easily tolerated, causing minimal discomfort), 2 = moderate (discomfort significant enough to interfere with daily activities) and 3 = severe (incapacitating and/or requiring therapeutic intervention)