大气细颗粒物微量有害元素和持久性有机污染物的吸入生物可给性方法优化及其吸入生物可给性研究

The investigations on the bioavailable contaminants in the atmospheric particulate matters, which can be absorbed by human organs, may reveal the toxic components during the inhalation exposure of atmospheric fine particulate matters. However, some problems on the in vitro bioaccessibility methods are still unclear, for example, effects of sampling membranes with different physicochemical properties on extraction performance, inapplicability to organic pollutants, and lack of validation. Therefore, according to the scientific problems of “Toxic components of the typical regional atmospheric fine particulate matters and methods for exposure research” in the national key research plan, the present study aims at in vitro inhalation bioaccessibility of the trace toxic elements and the typical POPs pollutants in the atmospheric fine particulate matters. Based on the investigations on effects of sampling membranes with different physicochemical properties on extraction performance, concentrations of the trace toxic elements and the typical POPs pollutants in rats’ organs were compared with them extracted using inhalation bioaccessibility methods to set up an effective in vitro inhalation bioaccessibility method. The inhalation bioaccessibility of the trace toxic elements and the typical POPs pollutants in typical atmospheric particulate matters was obtained using the newly established in vitro inhalation bioaccessibility method. The sources of bioaccessible trace toxic elements and the typical POPs pollutants were identified. This study will provide scientific reference for the study of exposure to toxic components in atmospheric particulate matters and for the assessment of the health risks from toxic components in the atmospheric particulate matters. It may also provide a unified and validated extraction agent for the interlaboratory study of the genetic toxicity posed by toxic components from atmospheric particulate matters.

大气颗粒物中生物有效态污染物的研究可以揭示大气细颗粒物吸入暴露的毒性组分来源，然而目前吸入生物有效性研究方法存在着忽视采样膜性质对提取影响、没有研究有机污染物和缺乏验证等问题。故围绕重大研究计划“典型区域大气细颗粒物的毒性组分及暴露研究方法”的科学问题，针对大气细颗粒物中微量有害元素和典型POPs污染物的生物可给性的问题开展本课题研究。在系统分析不同理化性质的采样膜和模拟大气颗粒物对大气颗粒物污染物吸入生物可给性影响的基础上，通过大鼠活体吸入暴露实验和吸入生物可给性离体实验结果比较，构建大气颗粒物中污染物的吸入生物可给性离体方法，进而评估典型大气颗粒物中微量有害元素和持久性有机污染物的吸入生物可给性、识别吸入生物可给态污染物的来源。分析大气细颗粒物吸入暴露毒性有效组分，为评估我国大气颗粒物污染健康风险提供科学参考，也为不同实验室间大气细颗粒物样品提取物遗传毒性研究提供统一的验证的提取技术。

大气颗粒物的吸入暴露是大气颗粒物中污染物对人类带来健康风险的主要途径。吸入的大气颗粒物中污染物与肺部生理溶液作用后溶解态污染物直接进入体液，而颗粒物残渣态进入体内或排出体外。因而，大气颗粒物中生物可给态污染物的研究是揭示大气细颗粒物吸入暴露的毒性组分来源重要研究环节之一，然而目前吸入生物有效性研究存在着忽视采样膜性质对提取影响、离体提取方法缺乏验证等问题。因而针对大气细颗粒物中有害元素的生物可给性问题开展本课题研究。本课题首先分析南京市大气颗粒物质量浓度和无机组分布特征及不同理化性质的石英和特氟龙采样膜对重金属元素吸入生物可给态离体提取的影响；其次通过纳米颗粒物和污染土壤模拟PM2.5颗粒的细胞培养/小鼠活体暴露实验获得活体生物有效性和离体吸入生物可给性实验的数据；接着分析活体生物有效性和离体吸入生物可给性相关性，优化大气颗粒物污染物的离体吸入生物可给性方法；最后分析南京室内外大气颗粒物中重金属元素的吸入生物可给性，评估其潜在吸入健康风险。本研究获得南京市大气颗粒物质量浓度和无机组分的分布模式及大气颗粒物重金属元素含量时空差异性特征数据；揭示特氟龙膜和高纯石英膜的理化性质差异影响采集的颗粒物的团聚及重金属元素的生物可给性元素特异性的规律；建立了通过纳米金属颗粒物和污染土壤快速模拟PM2.5颗粒方法；阐明纳米颗粒物模拟的PM2.5颗粒的生物可给性、细胞生物有效性和小鼠暴露生物有效性的机理，进而获得污染土壤模拟PM2.5颗粒中重金属不同离体生物可给性方法的生物可给性与滴灌法小鼠暴露重金属的生物有效性间相关关系，并基于离体-活体相关优化重金属铅的离体生物可给性方法。基于重金属吸入生物可给性南京室内外大气颗粒物中重金属元素吸入暴露存在潜在的健康风险。该研究为评估我国大气颗粒物重污染污染物吸入健康风险提供科学参考。