典型海滨城市大气中高毒性有机物的环境行为研究

Particulate matter poses a serious threat to the ecosystem and human health, characterized by the sequent occurrence of lasting haze events. The toxic effects of particulate matter are usually related to the organic part. However, there is still a lack of systematic understanding of the mechanism underlying how haze weather drives the evolution of atmospheric organic compound, especially organic substances with high toxicity and posed high risk of exposure through respiratory. This project intends to reconstruct the major reaction of the organic compound with high-activity and high-toxicity, combining the laboratory experiment and field observation, based on use a technology platform using chromatography with mass spectrometry. The influence of different levels of gaseous pollutants, particulate matter and the coastal environment on the atmospheric oxidation of organic compounds was detailedly studied; Simultaneous observation of highly toxic organic substances with different activity and different geographic origin and their oxidation product will be conducted. By the combination of statistical analysis and model construction, every environmental processes compartment will be studied to determine the influence of occurrence of haze weather on the evolution process of the typical organic pollutants with high toxicity. This project provides basic data for the mechanism underlying how haze weather drive the evolution of majority organic compound.

颗粒物污染是目前最突出的环境问题，它的毒性主要与其中的有机物相关，然而对雾霾天气如何驱动有机物尤其是高毒性有机物的大气环境行为变化并影响其呼吸暴露风险尚缺乏系统深入的认知。本项目拟以色质联用为平台，结合实验室模拟以及外场观测，对高活性有机物大气转化通路进行构建，探究气态污染物、颗粒物以及海滨环境对其影响；对不同活性、不同地理源高毒性有机物及其产物进行持续监测，以统计分析及模型构建为手段，分析其气粒分配、粒径分布、迁移转化等环境行为，确定雾霾天气的发生对典型高毒性有机物环境过程的作用机制，为雾霾天气下有机物的演化及颗粒物毒性研究提供参考数据。

颗粒物浓度增加是大气污染的主要特征，有机污染物是颗粒物质量浓度增加和颗粒物毒性效应的主要来源。在本项目中，我们研究了高丰度及高毒性有机污染物的污染特征变化规律以探究其在颗粒物质量及健康效应中的作用。建立了颗粒物中多环芳烃（PAHs）及其衍生物、多氯代二苯并二噁英/呋喃（PCDD/Fs）、短中链氯化石蜡（SCCPs和MCCPs）、多氯联苯（PCBs）、多氯萘（PCNs）等痕量高毒性组分、挥发/半挥发性有机物（VOCs/SVOCs）、水溶性有机物分子的高灵敏高覆盖度分析技术，分析了不同季节、不同粒径以及雾霾前后大气有机污染物。雾霾发生时，颗粒物尤其是积聚模态颗粒物浓度增加，积聚模态粒径增加，粗粒子粒径变小；SVOCs含量随颗粒物浓度的增加而增加，雾霾天气下，SVOCs构成发生显著变化，尤其是在积聚模态中；不同季节中，PAHs类、PCBs、PCDD/Fs、SCCPs等冬季浓度最高，MCCPs秋季最高，源排放特征的季节变化是同系物分布变化的主要原因；冬季颗粒物中高浓度重金属、PAHs等对大鼠脂质和GSH等代谢通路的协同作用是冬季颗粒物毒性较高的可能原因；研究了从排放源烟气到城区大气中PCDD/Fs的粒径及同系物分布演化，排放烟气中PCDD/Fs主要集中于粗粒子模态，传输过程中粗粒子模态及超细粒子模态颗粒物发生沉降，使得城区大气PCDD/Fs主要分布于积聚模态； PAHs类化合物及金属元素的粒径分布结果表明，粗颗粒中自然源污染物丰度较高，较小粒径颗粒物中人为源污染物丰度增加；基于FT-ICR MS的水溶性有机物的分子结构鉴定表明，积聚模态化合物种类最多，O/C最高，雾霾事件发生时有机物氧化度增加，积聚模态的含硫化合物急剧增加；污染物来源及其大气氧化是影响污染物粒径分布的主要因素；研制了大气有机物氧化反应研究装置，进一步研究了典型前体物在大气中与臭氧的反应历程并鉴定其主要氧化产物。