沙尘天气对生物气溶胶中总微生物浓度及粒径分布的影响

发布时间：2019-06-13 06:31

【摘要】：为了解沙尘对生物气溶胶中微生物的影响,于2015年3~4月间分别在兰州和青岛沙尘期间运用分级生物气溶胶采样器连续采集了生物气溶胶样品,并利用DAPI染色-荧光显微镜计数方法测定了总微生物浓度.结果表明,沙尘发生时生物气溶胶中总微生物浓度显著增加(P0.05).兰州和青岛总微生物浓度晴天背景均值分别为5.61×10~5cells·m~(-3)和2.08×10~5cells·m~(-3),沙尘时平均浓度分别是晴天的14.8倍和6.42倍.晴天时兰州和青岛两地样品微生物粒径分布均呈双峰分布,最高峰值均出现在7.0μm的粒径上,最低值均出现在4.7~7.0μm的粒径上,浓度次高峰值分别出现在3.3~4.7μm的粒径上和1.1~2.1μm的粒径上.沙尘时粒径分布均发生明显变化,兰州仍呈现双峰分布,但其中一个峰值从7.0μm移动到1.1~2.1μm;而青岛粒径由双峰分布变为粗粒径偏态分布.兰州和青岛沙尘前微生物负荷的背景值分别是2 224 cells·μg~(-1)和1 550 cells·μg~(-1),而沙尘发生时,颗粒物的微生物负荷均大幅增加,最高值分别达26 442 cells·μg~(-1)和10 250 cells·μg~(-1),这说明沙尘天气发生时,微生物浓度的增加不仅仅是因为空气中颗粒物的增加,而是因为长距离传输的沙尘颗粒携带有大量外源微生物.
[Abstract]:In order to understand the effect of dust on microorganisms in biological aerosols, the samples of biological aerosols were collected continuously by graded biological aerosol samplers during Lanzhou and Qingdao dust from March to April 2015, and the total microbial concentrations were determined by DAPI staining and fluorescence microscope counting method. The results showed that the total microbial concentration in biological aerosols increased significantly (P 0.05). The background mean of total microbial concentration in Lanzhou and Qingdao was 5.61 脳 10 ~ 5cells 路m ~ (- 3) and 2.08 脳 10 ~ 5cells 路m ~ (- 3), respectively. the average concentration of sand and dust was 14.8 times and 6.42 times of that in sunny day, respectively. On sunny days, the microbial particle size distribution of Lanzhou and Qingdao samples showed bimodal distribution, the highest peak appeared on the particle size of 7.0 渭 m, the lowest value appeared on the particle size of 4.7 ~ 7.0 渭 m, and the second peak value of concentration appeared on the particle size of 3.3 ~ 4.7 渭 m and 1.1 ~ 2.1 渭 m, respectively. The particle size distribution of sand and dust changed obviously, Lanzhou still showed bimodal distribution, but one of the peaks moved from 7.0 渭 m to 1.1 ~ 2.1 渭 m, while the particle size of Qingdao changed from bimodal distribution to coarse particle size skewness distribution. The background values of microbial load before sand dust in Lanzhou and Qingdao were 2224 cells 渭 g ~ (- 1) and 1.550 cells 渭 g ~ (- 1), respectively, while the microbial load of particulate matter increased significantly when dust occurred, with the highest values of 26442 cells 渭 g ~ (- 1) and 10.250 cells 渭 g ~ (- 1), respectively, which indicated that the increase of microbial concentration was not only due to the increase of particulate matter in the air. It is because long-distance dust particles carry a large number of exogenous microorganisms.
【作者单位】：中国海洋大学海洋环境与生态教育部重点实验室;
【基金】：国家自然科学基金项目(41375143) 教育部新世纪优秀人才支持计划项目(NCET-13-0531)
【分类号】：X513

【参考文献】