广州市秋季室内外空气细菌谱及其气溶胶分布特征

The distributive features of indoor and outdoor bacterium aerosol grain in residential area of Guangzhou City

目的研究广州市普通住宅小区室内外微生物气溶胶细菌谱与粒径分布的特征。方法选择灰霾天气期间，采用分粒径采样对广州市普通住宅小区室内外细菌气溶胶进行连续的种类、粒径、数量检测。结果室内空气中共出现8属18种空气细菌，其中革兰阳性菌4属11种，革兰阴性菌4属7种，革兰阳性菌占79．5％，室外空气中共出现8属15种空气细菌，其中革兰阳性菌4属9种，革兰阴性菌4属6种，革兰阳性菌占82．4％。室内外优势细菌依次为藤黄微球菌（M．luteus）、表皮葡萄球菌（S．epidermidis）、芳香产碱杆菌（A．Odoratum）。室内外空气细菌气溶胶粒径分布基本一致，呈偏态分布，其中69．8％-72．9％的细菌气溶胶颗粒沉降在3—6级。室内外气溶胶中同种细菌粒径分布并非一致，说明细菌形成气．溶胶后粒径发生变化，可能与形成气溶胶的成分有关。结论室内空气细菌总数虽然低于国家标准，但其中约70％的细菌沉降于人体下呼吸道，空气质量不容乐观。

Objective To survey the distributive features of bacterium aerosol in Guangzhou City. Methods During haze weather from October 19 to 28, 2005, the bacterium aerosol was continuously tested indoors and outdoors in ordinary residential district in Guangzhou using samplers of different particle size. Results On different floors, at different periods of a day, the air bacterium aerosol count distribution indoors was almost the same as that of outdoors; the indoor bacterium aerosol count was between 204-2 530cfu·m^-3 （geometry average 2.72 ± 0.32cfu·m^-3 ）, the outdoor bacterium aerosol count was between 95 - 1 717cfu·m^-3 （ geometry average 2. 53 ± 0. 31cfu·m^-3）. Indoor and outdoor distribution of air bacterium aerosol remained consistent, assuming skewed distribution, with 69.8%-72.9% bacterium aerosol settling in the 3 -6 level where this section of particle sizes is similar to the human lower respiratory tract. Conclusion Although indoor air bacterium count is lower than the national standard, approxlmately 70% bacteria subside at the human＇ s lower respiratory tract. This means the air quality is far from being optimistic.