京津冀区域大气细颗粒物的标准化样品采集和表征

At present, many projects have been granted to assess the toxicology and adverse health effects of PM2.5 from the typical regions. The scientificity of the assessment will be affected if the sampling or analytical methods are not normalized because of the complexity of PM2.5, which limits the comparison of data from different labs and decision making. This project will select typical national environmental monitoring sites from representative cities (Beijing, Tianjin and Shijiazhuang) of the Beijing-Tianjin-Hebei region, which is most heavily air polluted region in China, to study the standardization of sampling and characterizing for the physicochemical properties/components of PM2.5. Based on national/industrial or international authority methods, standardized sampling and characterizing methods will be established and qualified alternative solution will be recommended. Aiming at typical components, quality control (QC) samples meeting the requirements of the international standard will be developed and some national authority labs will be involved to set up a platform for mutual testing for sampling and characterizing of PM2.5 samples. Technical standards of assessment and QC of inter labs will be established to ensure the scientific sampling and rational characterizing. The accuracy, precision and applicability of the methods will be emphasized to ensure the representativeness and reliability of the collected samples. Afterwards a PM2.5 specimen bank will be set up and PM2.5 samples with sufficient information and reliable source will be supplied for other relevant projects granted to verify their research methods and proposed toxicological mechanism.

目前围绕大气细颗粒物（PM2.5）毒理和健康效应的项目很多。鉴于PM2.5的混合物特性，采样和表征方法不规范的问题直接影响结论的科学性，制约不同实验室间数据的比对和决策支持。本项目拟选择污染最为严重的京津冀区域代表性城市（北京、天津和石家庄）典型国测点为示例，开展PM2.5的采样与理化性质/组分表征标准化研究。立足于国家/行业标准或国际权威方法比较，构建全程质量保证/质量控制体系和PM2.5样品的采集和表征标准化方法及符合要求的推荐替代方案。针对典型组分研制符合国际规范的PM2.5质控样，并选择国内权威实验室建立PM2.5样品采集与表征环测平台，建立实验室间评估与质控规范，以确保科学采样与合理表征，注重方法的准确度、精密度及开放性等，保证样品的代表性和表征结果的可靠性。建立典型区域PM2.5标准样品库，为计划的毒性研究项目提供信息完备、来源可靠的PM2.5样品以供研究方法和毒性机制的验证。

大气细颗粒物（PM2.5）的标准化采集和表征对于PM2.5的溯源、防治及毒理健康评价至关重要。本项目在京津冀代表性城市（北京、天津和石家庄）的3个典型国测点、中科院生态环境研究中心和1个北京郊区对照点设立了5个大气PM2.5采样站点。参照相关国家标准和经典方法，并结合项目实情，制定了标准化的采样操作规程，对京津冀地区的PM2.5进行了长期连续的采集。截至目前，共采集了15045个大气样品，包括中流量样品约5500个和大流量样品约9500个。建立了标准化的样品库和样品信息管理系统，方便了样品的保存和信息查询。通过改进滤膜等分器，实现了大气样品不同等分的需求。在此基础上，对大气PM2.5中的金属组分、水溶性离子、有机碳和元素碳等进行了表征，并对分析结果进行了评估并制备了4种质控样。结果显示表征方法的准确度、精密度和检测限等均达到了PM2.5表征的技术要求。利用采集的样品对京津冀大气中9种有机磷酸酯（OPEs）和8种新型溴代阻燃剂（NBFRs）的赋存水平与分布特征进行了研究。结果显示所有采样点收集的样品中均检出OPEs和NBFRs的存在，并且发现温度和大气总悬浮颗粒物是影响大气中污染物时空分布的重要因素。另外还构建了多维金属指纹溯源的方法，追溯了不同时期北京市PM2.5的特征及来源。抽样分析了2018-2020年京津冀区域PM2.5样品中主要组分的时空分布规律。这些结果为深入了解我国典型区域大气中典型污染物的环境行为特征提供了科学依据。在本项目资助下已经发表学术论文36篇，其中标注第一致谢SCI论文17篇，培养博士研究生5名和硕士研究生3名，圆满完成了项目的各项考核指标。