中文摘要：

采用分粒径撞击法监测细菌气溶胶的粒径分布特征，并与沉降法检测结果进行比较．研究结果显示，分粒径撞击法和自然沉降法测得空气细菌总数间存在显著的正相关关系；自然沉降法获得的细菌总数约占撞击法18％，并与撞击法第一级采集的细菌总数基本一致（P〉0．05）．约70％的细菌分布在撞击法3-6级，该粒径范围的细菌与人体下呼吸道疾病密切相关．结果表明，计数空气中细菌数量可能能够反映与细菌性疾病流行的关系，而细菌在不同粒径的气溶胶中分布可能对特定疾病如呼吸道细菌感染更为重要．分粒径进行细菌计数可能对监测空气质量更有意义．

英文摘要：

The distribution of bacteria with different granularity in bacterial aerosols was studied using particle impact collection, and the total number of bacteria collected with this method was compared with the results from a traditional precipitation method. The total number of bacteria colony counts collected by the impact method was significantly correlated with the number measured by the precipitation method. The total number of bacteria colony counts from traditional precipitation was about the same as that of grade 1 level （p 〉 0. 05） of the impact collector, corresponding to 18% of total colony counts. Approximately 70% of the bacteria were distributed in grades 3 - 6 of the impact collector. Since the particle sizes of these grades are closely related with lower respiratory tract diseases, these results implied that compared to the total number of bacteria in the aerosols, differential counts of bacteria granularities may be more relevant to specific respiratory bacterial infections. Thus differential counts of bacteria granularities are recommended as the air quality monitoring protocol.