邻苯二甲酸酯在典型城市区域的环境地球化学过程及光解转化机制研究

Phthalate esters are a kind of typical environmental endocrine disrupting chemicals. They are a class of man-made organic chemicals widely used as plasticizer in polyvinyl chloride plastics and other common consumer products. Known as the endocrine disrupting chemicals, they may have carcinogenic, estrogenic, and endocrine disrupting characteristics of animals and humans. Because of their widespread existence in the environment and even biological samples, they have drawn great environmental concerns. Therefore, the pollution characteristics and sources analysis studies of phthealate esters are of great significance. However, few data are available depicting PAEs current pollution status in the outdoor/indoor atmosphere and dust of Shanghai.The photochemical reaction mechanisms of PAEs on dust surface are also not very clear. This project is carried out in four different areas, i.e. industrial area, communication hub, commercial district and living area. Based on establishing the rational analysis methods of PAEs in the samples of stmosphere and dust, the project is performed to discuss the pollution characteristics, the spatial-temporal distributions and the probable source of PAEs. Beside, the transformation regularities between indoor and outdoor environment, distribution regularities between etmosphere and dust and the distribution between gas phase and airborne particles were expounded in this study. In addition, health risks of humans were assessed. Moreover, this project employing simulated sunlight as induced light source, and combining time-resolved laser flash photolysis technique, the macro and micro-photo-induced reaction mechanisms of PAEs on typical PAEs surface will be in-depth explored, the photo-induced transformation products and their toxicities will be researched as well.The results of this study plays an important role in understanding the contamination levels and the potential health risks of PAEs in indoor and outdoor environments, and could provide some support to environmental fate and eco-city management of Shanghai.

邻苯二甲酸酯（PAEs）是一类内分泌干扰物，具有三致毒性，在环境中广泛存在。而目前国内外对PAEs在城市室内、外环境（包括大气气相、颗粒物相和灰尘）中的研究还不成熟。灰尘作为污染物在环境中主要的汇，PAEs在其表面的光化学转化机理并不清楚。本研究在建立合理大气和灰尘样品PAEs分析方法的基础上，详细研究上海市室内外环境中PAEs在工业区、交通要道区、商业区和生活区的时空分布、污染水平，结合环境数据，重点揭示上海市室内外环境中PAEs的污染特征，分析其来源，着重阐述其在室内外环境间的迁移规律，在大气和灰尘间的分布规律，在气相/颗粒相间的分配规律及其影响因素，初步评估其在上海市居民摄入的暴露水平。采用模拟太阳光结合激光光解技术，深入了解PAEs在灰尘中的光解特性和转化机制，鉴别光解过程的产物及其生物毒性。为科学评估PAEs的环境污染水平、环境归趋和和潜在的健康生态风险提供可靠的基础科学数据。

本课题以多种典型的邻苯二甲酸酯类物质（PAEs）为研究对象，深入调查了其在上海地区水体、沉积物和大气中的污染水平、时空分布，并其来源进行解析，评估其生态风险。采用激光光解和脉冲辐解研究了典型PAEs 的瞬态降解机理。并以三种磺胺类药物（SMX、SMZ和STZ）为研究对象，研究了其降解动力学和降解机理。所得结果此类污染物的预防及制定相关的措施提供一定的理论依据。主要研究结论为：（1）PAEs在上海市水体中广泛存在，总体上处于较低水平。两个季度中，浓度较高的采样点位于上海市区周围和电子商业城区。其在沉积物中的浓度普遍高于水体中，和水体中呈相似的分布特征，但季节性变化不大。对水体和沉积物中典型的PAEs进行风险评价，发现目前其没有明显的生态风险。（2）PAEs普遍存在于可吸入大气颗粒物中。其中DEHP、DBP和DIBP为主要的组成部分，且DEHP在PM2.5和PM10中处于夏季中，明显高于其在冬季中的浓度。在气相中， DEHP依然占据主要地位。对不同年龄段的致癌风险由高到低为成人、儿童、青年，皆高于USEPA规定的可忽略值，存在一定的人体健康风险。因此对于PAEs在大气中的含量，亦不可忽略。（3）在激光的激发下，DMP只会发生光激发。DMP能与•OH、eaq- 和SO4-• 发生反应。与•OH发生苯环上的加成反应，形成羟基加成物；与eaq- 发生酯基上的电子转移反应，形成阴离子自由基；与SO4-•反应形成阳离子自由基，该阳离子自由基与水反应又形成羟基加成物。在O2饱和体系中DMP与•OH反应生成的羟基加成物进一步与O2反应形成过氧自由基。（4）在不同的浓度下，三种磺胺类药物的降解均遵循假一级动力学。STZ的降解率比SMX和SMZ的降解效率快。溶液的初始浓度、溶液初始pH值、不同水质、无机离子、自由基清除剂和H2O2对三种磺胺类药物的降解的都存在影响。结合离子色谱和液相色谱质谱联用的分析结果，提出了SMX、SMZ和STZ的降解机理。发现SMX和SMZ的降解过程均要比STZ的降解过程复杂一点，这可能跟噻唑环和恶唑环的结构有关系。发光细菌实验表明磺胺类药物的中间产物不会对环境产生新的影响。