电子垃圾拆解排放典型大气毒害有机污染物的环境地球化学转化过程及其人体代谢产物研究

The release of organic contaminants into air during the electronic waste (e-waste) dismantling processes has gained increasing concern recently, due to their potential adverse effect on the atmospheric environments and human health. This project aims to have a full insight into the environmental geochemical transformation mechanism of typical volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in the atmosphere emitted from an e-waste recycling site in southeast China, and their health impact on the e-waste dismantling workers as well as to the residents lived nearby were also considered. At the aforementioned region, a national e-waste dismantling exemplary park has been built recently and require all the previous individual workshops to enter this park within 2-3 years, where the e-waste will be dismantled using innovation dismantling technology to minimize the negative impact of our present and future generations on the environment and to create a sustainable future. First, to better understand the dynamic levels of atmospheric contamination of PBDEs, PCBs, PAHs and VOCs, as well as their potential geochemical transformation products, the air samples of TSP, PM10, PM2.5, and VOCs in the Guiyu Town (total area of 9 km × 9 km) including the exemplary park were analyzed before and after the establishment of the dismantling exemplary park, based on gridded field observations. Further, the transformation mechanisms of the pollutants in the air were also investigated through the time and space changing within this region. Second, to fully insight into the source, transformation mechanisms as well as the potential health risk of the transformation products in the atmosphere to the people, the photolytic degradation kinetics and mechanisms of the typical VOCs and SVOCs in the air in the absence and presence of particles (SiO2 as well as practical particles sampled at this area) under the UV and sunlight irradiation will be investigated both using the theoretical calculation as well as on-site observation. Meanwhile, the relationship of the original and transformation mechanism as well as the fate of typical organic contaminants were also seriously considered, and the matched non-invasive matrices urine, hair, nail, and exhaled breath will be used for the biomonitoring of human exposure to the air bound organic pollutants emitted from e-waste dismantling activity based on long period tracking. Finally, the relationship between the people’s health with the pollution level, transformation mechanisms, and the human exposure of atmospheric toxic organic contaminants emitted from e-waste dismantling processes also will be attempted. The successful accomplishment of this project will provide many first-hand fundamental knowledge of the transportation, transformation, environmental fate of atmospheric toxic organic contaminants emitted from e-waste dismantling processes and their potential health risks to the workers as well as the local residents.

本项目将以我国最大的电子垃圾拆解基地-汕头市贵屿镇作为研究示范区域，重点开展在国家示范园区建设过程中拆解商户入园前后，在贵屿镇(含园区)开展大尺度大气有机污染物及其转化产物的时空变化的对比研究，重点探讨园区内外利用新旧拆解工艺拆解不同线路板排放大气污染物的污染特征与污染机制差异。开展典型重污染物的大气环境光化学转化研究，并结合理论化学计算方法探讨典型大气转化产物的源汇关系、形成机理、迁移转化机制及其对人体暴露的潜在危害性。并通过多种无创采样检测手段，跟踪对比研究园区内外暴露人群的人体代谢产物特征，建立大气污染物通过呼吸和皮肤等暴露途径与人体内暴露代谢产物的关系，筛选并鉴定特异性代谢标志物，寻找典型污染物的排放特征、代谢产物及其转化机理与人群暴露风险的相关性。项目成功实施可为电子垃圾拆解排放大气污染物的环境地球化学转化、暴露风险评价、潜在人体健康效应和区域环境保护提供坚实的第一手科学资料。

电子垃圾在回收与拆解过程中会排放大量的毒害污染物。本项目以我国最大的电子垃圾拆解基地-汕头市贵屿镇作为研究示范区域，①重点开展了在该区域国家示范园区建设过程中拆解商户逐步入园前后，在贵屿镇区域开展大尺度大气有机污染物及其转化产物的时空变化的对比研究，发现电子垃圾拆解园区大气中PBDEs、tri-OPEs和di-OPEs的浓度明显高于周围，电子垃圾拆解是该地区大气中这些污染物的主要来源。周围地区颗粒物浓度有逐年下降趋势。BTEX污染特征变化主要发生在2015年春和夏之间，电子垃圾集中拆解后区域BTEX污染无年际变化趋势。②在烟雾箱对芳香烃类VOCs的大气光化学行为进行研究，发现氮氧化物的存在促进了芳香烃的光氧化，并显著影响了最终的气相和颗粒相产物形成机理。同时发现苯环上甲基取代基的数量减少了芳香烃的氧化程度，臭氧会随着甲基数量的增加而生成和积累。通过理论化学模拟研究了小分子量α-二羰基化合物低聚反应机理及其对SOA贡献机制，提出小分子量α-二羰基化合物在弱酸性气溶胶及云/雾滴中的阳离子介导反应机理，揭示反应过程中碳正离子的出现是其能够快速聚合形成SOA的关键因素。③采集人体相关样品(包括血清、尿液、头发、皮肤擦拭和人体呼吸排出的VOCs气体)，并开展典型污染物的人体暴露与代谢产物标志物的筛选。发现皮肤擦拭样品中的磷酸三苯酯和配对尿液中的磷酸二苯酯之间显著相关性高，磷酸三苯酯可作为有机磷阻燃剂皮肤暴露的特征性标志物。皮肤暴露于磷酸三苯酯会导致血清甲状腺激素水平的变化。在电子垃圾管控后不同人群尿液中的PAHs、BTs和重金属暴露水平及其诱发的非致癌风险均有下降，尤其是对于儿童。尿液中的1-OHP和Sn可以作为特异性生物标志物。所有这些研究可为电子垃圾拆解排放大气污染物的环境地球化学转化、潜在人体健康效应等提供一手科学资料。相关研究内容发表SCI 86篇，第一标注SCI论文76篇，申请专利9件。获环境保护科学技术一等奖和广东省自然科学一等奖各1项、长江特聘教授、国家“万人计划”科技创新领军人才、全国模范教师、科技部创新人才推进计划中青年科技创新领军人才、广东特支计划杰出人才、广东省五一劳动奖章、广东省五一劳动奖状和广东省丁颖科技奖等。