Abstract: ObjectiveTo study the effects of air pollutants on pulmonary inflammatory cytokines in rats,and to explore the mechanism of air pollution on inflammatory injury of respiratory system.MethodFourty-eight Wistar rats(200~240 g)were randomly divided into treated groups(1 d,7 d,and 30 d groups)and control group.The tested rats were respectively exposed to PM 10 of 15 mg in 1 ml saline by intratracheal instillation,and then were exposed to mixed gases of SO₂,NO₂,and CO(15,12,and 400 mg/m³ respectively)by static inhalation 2 h per day for 1 d,7 d and 30 d respectively.One ml saline was instilled and general air was inhaled by rats of the control group.ResultsThe counts of white blood cell(WBC)and the percentages of neutrophil(Neu)in treated groups were significantly higher than those in the control group(P<0.05 or P<0.01).The levels of TNF-A,IL-6,IL-8,and IL-10 in rats of one-day group were significantly higher than those in the control group(P<0.05).There were positive relationships among cytokines.ConclusionAir pollutants can induce the imbalance on the expression of pro-and anti-inflammatory cytokines and resultin inflammatory injury of respiratory system.