基于脆弱性的大气颗粒物重金属健康风险研究

Current demands in controlling and reducing human health risk caused by heavy metal pollutions in airborne particles, as well as gaps in health risk assessment, calls for expanding the scope of human health risk assessment. The human vulnerability, which plays important roles in human response to heavy metals in airborne particulate matters, is proposed to be included in human health risk assessments. The study will be carried out in Nanjing, which is a representative city in Yangtze River Delta. Firstly, analysis of the contents and chemical speciation of heavy metals is carried out. And the chemical speciation, which refers differential biological effectiveness, is taken in account in typical human health risk assessment to revealing health risk more precisely. Secondly, an index system is established involving four aspects of vulnerability-susceptibility, exposure, preparedness and the ability to recover from the future harm. The relevant data is collected by investigation on socioeconomic, exposure, risk perception et al. Multivariate statistical analysis and GIS spatial analysis are adopted in modeling and assessing the vulnerability. Thirdly, a benchmark value of vulnerability is proposed by referring to the background in which the US benchmarks for health risk assessment, as well as the social and economic background of study area. The vulnerability assessment outcomes are standardized by the vulnerability benchmark, which are used for amending the human health risk assessment outcomes obtained through U.S. EPA's mode1 after considering the bioavailability of atmospheric heavy metals. The amended health risks may perfectly depicts both human exposure in pollutions and their ability to prevent, reduce and adapt the health risk. Thus the population in high risk can be exactly screened out, as well as the key nodes for reducing population health risk.

本研究立足大气颗粒物重金属健康风险管理现实需求和健康风险研究的不足，以长三角典型城市-南京为研究对象，尝试将人群脆弱性纳入健康风险评估。首先，在PM10、PM2.5中Pb、Hg、Cr、Cd、As的浓度和形态分析基础上，结合暴露参数调查，参考美国 EPA方法进行人群健康风险评估；其次，从易感性、暴露、响应能力和恢复能力等四个方面选取脆弱性指标，结合社会经济调查、暴露调查和风险感知调查，采用GIS空间分析技术和多元统计方法，建立人群脆弱性评估体系，获得人群脆弱性指数；最后，参照美国健康风险评估基准确立的背景，确立脆弱性指数基准值，对脆弱性指数进行标准化，并利用标准化结果对基于形态学的健康风险评估结果进行修正，修正后的健康风险水平更能系统地反映人群在重金属污染场中的暴露及其对健康风险的防控、减缓和适应能力，从而为准确识别高风险人群，筛选降低人群健康风险的关键节点提供科学依据。

本研究立足大气颗粒物重金属健康风险管理现实需求和健康风险研究的不足，以长三角典型城市-南京为研究对象，尝试将人群脆弱性纳入健康风险评估。首先，为探讨南京市不同学生人群健康风险的暴露参数，本研究采用问卷调查法对南京市大学、中学和小学三种学生人群经口摄入、皮肤接触、呼吸吸入等三种暴露途径的暴露参数进行调查，从而获得三种学生人群的基本特征参数、呼吸暴露参数、饮食和饮水暴露参数、皮肤暴露参数、室内外暴露时间等一系列暴露参数；其次，为摸清南京市北郊不同粒径大气颗粒物的污染状况、来源及风险，于2014年冬季和2015年夏季采集南京信息工程大学浦口校区观测场室内外TSP、PM10、PM5、PM2.5样品，并分析样品中As、Cr、Mn、Cu、Ni、Pb和Zn等7种元素。系统分析不同粒径大气颗粒物及其中As和6种重金属元素的污染水平，运用富集因子法和主成分分析法分析得到冬季颗粒物中7种元素的来源主要包括交通源、地表扬尘、工业排放等；潜在生态风险评估显示冬季大气颗粒物中7种元素的生态风险为极强；健康风险评估显示PM2.5中7种元素对小学生的危害最大，其次是中学生，对大学生的危害最小，其年均超额危险度均未超过人群可接受危险水平1×10-6，对人体危害在可接受范围。再次，为深度解析不同人群面临大气颗粒物重金属污染暴露的脆弱性，从风险感知、易感性、暴露、响应准备水平和恢复能力4个方面出发，设计公众调查问卷，先后调查了南京市大学生空气污染风险感知、南京市化学工业园附近居民环境风险感知以及盐城市居民环境风险感知和脆弱性。该研究理论层面，可从暴露和社会易损性两个角度深入解析颗粒物中重金属污染风险的人群易损性机理，并将室内、外颗粒物重金属浓度差异和人群风险感知分别纳入暴露模型和易损性指数的研究中；应用层面，通过PM2.5中重金属污染风险的人群易损性机理解析和综合表征模型构建，为区域大气环境污染风险条件下增强人群受体的抗风险能力提供技术支撑。已撰写学术论文10篇。其中7篇已发表（1篇SCI，2篇EI，4篇核心），1篇已接收（核心），已投稿2篇（SCI）。培养研究生3名。