Free lung cell response after combined exposure to cigarette smoke and industrial dusts

Guinea pigs were acutely exposed to different airborne dusts and freshly generated cigarette smoke. The effect was evaluated by counting the number of free lung cells using a lavage method. An exposure to MnO2 and smoke on the same day caused an increase in the number of leukocytes 24 h thereafter. By increasing the time interval between the MnO2 and smoke exposure, the effect gradually disappeared. Al2O2 or SiO2 also caused an increase in the number of leukocytes, whereas TiO2 had no effect. The pathogenesis behind the reaction and the epidemiological implications are discussed.