Abstract: Objective Adverse health effects of indoor air PM₁₀ and air-borne fungi on lung were studied by observation on animals exposed to those air pollutants.Methods SD rats were inoculated via treachea with suspensions of PM₁₀,dominant fungi spores and their mixture for a month.The pulmonary pathological injury and the following indexes in bronchoalveolar lavage fluid were examined,(1)levels of ALB,(2)activities of LDH,ACP,AKP,(3) amount of alveolar macrophage and individual percentages of three kinds of immune cells.Results The levels of ALB and activities of LDH,ACP,AKP in exposed groups were significantly higher than those in control.The amount and percentage of alveolar macrophage in exposed groups were significantly lower than those in control,while the percentage of neutrocyte had a reverse change.Inflammatory pathological changes of lungs were also observed in exposed groups.The dose-response relationships were obseved in the indexes.The statistics analysis showed that PM₁₀ and fungi had a joint additive effect on lungs.Conclusion Indoor air PM₁₀ and air-borne fungi could induce rat pulmonary injury and could have an additive effect on the two pollutants.