沙尘天气对近海大气中生物气溶胶粒径分布和微生物活性及群落结构的影响

Bioaerosols are important subgroup of atmospheric environment. And bioaerosols affects the environmental quality, human health and climate variation. The dust events inject a large pulse of microorganisms into the atmosphere and can therefore have a role in transporting bioaerosols or expanding the biogeographical range of some organisms by facilitating long-distance dispersal events. Microbiota contained within dust could impact downwind distribution and transportation of bioaerosols. This project will collect the bioaerosols samples under the dust and non-dust weather in the coastal region of the Yellow Sea, and investigate the size distribution of bioaerosols. The microbial community and predominant species of microorganism in bioaerosols will be analyzed in the dust events. The level and distribution of microorganism activity of bioaerosols will be studied. The microorganism activity and community of inhalable particulates will be evaluated. The impact of weather parameters and chemical substances on the concentration and size distribution of different kinds of bioaerosols (including bacteria, fungi and total microbes) will be analyzed. The results will be contributed to reveal the impact mechanism of the dust event on the property, distribution and transportation of bioaerosols and evaluate the environmental and climatic effect of bioaerosols thoroughly.

生物气溶胶是大气气溶胶的重要组成部分，对环境质量、人体健康和气候变化具有重要影响。生物气溶胶可借助沙尘暴进行长距离输运，影响空气中微生物的分布和传输，并会扩大一些有机体的生物地理范围。本项目拟采集沙尘和非沙尘天气下黄海近海生物气溶胶样品，阐明沙尘天气下生物气溶胶微生物粒径谱特征，解析沙尘天气下生物气溶胶中微生物群落结构和优势微生物，认识沙尘天气下生物气溶胶中微生物活性水平和分布特征，评价可吸入粒子的微生物活性和群落结构特征，分析沙尘天气条件和颗粒物化学组分对生物气溶胶中不同种类微生物(细菌,真菌,总微生物)浓度和粒径谱的影响。研究结果将为揭示沙尘事件对生物气溶胶的性质、分布和传输的影响机制提供科学依据，将为深入研究生物气溶胶的环境和气候效应提供重要参考。

沙尘等特殊天气对生物气溶胶的性质、分布、环境效应和健康效应具有很大影响。本项目建立了生物气溶胶中微生物活性分析的FDA（荧光素双醋酸酯）水解法，分析了沙尘、霾等天气下黄海近海以及海洋生物气溶胶中的微生物浓度、微生物活性及群落结构。结果显示，生物气溶胶中99.5%以上的微生物为不可培养类，沙尘天气下可培养类微生物的贡献略有下降。非沙尘天气下，总微生物、可培养微生物浓度和粒径没有显著的月季变化。沙尘天气下，生物气溶胶中总微生物、可培养细菌和真菌及四类优势真菌属浓度比晴天增加了0.3- 123倍，总微生物和可培养微生物粒径分布中粗粒子比例显著增加。生物气溶胶中的微生物活性在沙尘天明显高于晴天，粒径分布随沙尘强度有所差异。沙尘发生时，生物气溶胶中的细菌丰度明显增加，真菌群落结构和优势菌属比例发生了改变。海上生物气溶胶样品中总微生物浓度呈现青岛近海>西北太平洋>南海>黄渤海的空间分布特征，粒径分布与青岛近岸存在较大差别。生物气溶胶中的微生物活性低于青岛近岸，表现为西北太平洋>南海>黄渤海，不同海域微生物活性的粒径分布不同。海洋气溶胶中细菌群落结构复杂多样，黄海和西太气溶胶中细菌群落丰富度和多样性均是粗粒径高于细粒径。雾、霾天对微生物浓度、活性和群落结构亦有很大影响。研究结果可为深入研究生物气溶胶的环境和气候效应提供重要参考。