西安市典型场所微生物气溶胶的分布特征

Particular features of the microbial aerosols in the typical spaces in Xi' an Municipality

为阐明西安市不同功能区域微生物气溶胶分布特征,采用国际通用的Andersen-6级撞击式空气微生物采样器,于2016年3—5月间对西安市5处典型场所(公园、大学校园、公交车站、医院门诊区、污水处理厂)微生物气溶胶进行采样,利用平皿培养和菌落计数法检测分析细菌和真菌气溶胶的浓度、粒径分布和中值粒径。结果表明:不同场所细菌和真菌气溶胶的浓度存在差异,细菌和真菌气溶胶浓度的最大值分别出现在医院门诊区(3 352 CFU/m3)和污水处理厂(2815 CFU/m3);不同场所微生物气溶胶的粒径分布存在差异,细菌和真菌气溶胶分别主要分布在前4级(>2.1μm)和第3、4、5级(1.1~4.7μm);这5处典型场所的微生物气溶胶中值粒径从大到小依次为公交车站、大学校园、污水处理厂、医院门诊区、公园,其细菌气溶胶中值粒径均大于真菌气溶胶中值粒径。

This paper is aimed to identify and determine the distribution features of the microbial aerosols that have been emitted from the typical areas in Xi＇an Municipality. For this purpose,we have collected and chosen typical microbial aerosols with an Andersen 6-stage Impactor in the five typical places of the city,that is,the park area,the college and university campus,the bus station,the hospital outpatient service area,and the sewage treating plants from March,2016 to May,2016. And,then,we have categorized and determined the content concentration rates,the size distribution rates and the medium sizes of the airborne bacteria with the plate culture and the colony-testing methods. In addition,we have also regulated and classified the data collected with the help of the corresponding public health and medical workers in addition to the data and information of the traffic and transportation sections at the respective sampling sites,including the data on temperature,humidity and wind velocity. Finally,we have worked out the difference and gap between the content concentration rates of the bacterial aerosols and the fungal aerosols,as well as the similar data of the different sampling sites between the bacterial aerosols and those of fungi through the SPSS Statistics17. 0. The results of our investigation indicate that different concentration distribution rates can be found in different sampling spots,with the highest concentration rates of bacteria and fungi aerosols clustered in the medical and hospital quarters（（ 3 352 ±1 053） CFU/m^3） and the sewage-treating plants（（ 2 815 ±1 129） CFU/m^3）. What is more,the college and university campuses,the bus stations,the hospital clinical and patient service areas are mainly places belonging to the first 4 levels（ 2. 1μm）,whereas the sewage treatment plants are mainly suffering from the first 3 level（ 3. 3 μm）. As to the parks and the university campuses alike,they are attributed to level 3-5（ 1. 1-4. 7μm） places. At the same time,the bus stations university campuses sewage treatment plants hospital outpatient service areas the parks can all be categorized into medium sufferers of aforementioned aerosols. In addition,the median sizes of the microbial aerosols we have found in our study are all less than 5.0μm.