Gas sampling installations assembled by ourselves were used to study photocatalytic degradation of polycyclic aromatic hydrocarbons(PAHs) in cigarette smoke.PAHs in the samples were analyzed by gas chromatography with mass selective detection.Results show that the photocatalytic degradation effect of low-ring PAHs was determined by quantity of TiO2,while the photocatalytic degradation effect of high-ring PAHs was determined by intensity of UV-C light.Under weak UV-C light,photocatalytic degradation efficien...