大气挥发性有机污染物与肺表面活性物质间的界面化学作用研究

Respiration is a primary route of human exposure to Volatile Organic Compounds (VOCs). Lung is a foremost target organ of inhaled VOCs and is also the entrance by which VOCs enter human body. The alveolar lining fluid, an essential component of air-blood barrier, comprises Pulmonary Surfactants (PS), the vital matters that can stabilize alveoli by regulating the surface tension and then guaranteeing the normal pulmonary respiratory. The interfacial properties of PS are the physicochemical bases of functions of PS. The interactions between VOCs and PS would change the interfacial properties of PS and consequently impair the respiratory function of lung. Furthermore, the biotransport and biotransformation of VOCs in alveoli would inevitably be impacted by the interactions. For the purpose of ascertaining interaction mechanisms and their health effects, this project will investigate the following aspects by means of interfacial chemistry: 1) The influences of VOC exposure on the PS surface activity associated with respiratory function; 2) The influences of VOC exposure on interfacial properties of PS; 3) The partitioning of VOCs among multiphase of alveoli; 4) The mass transfer mechanisms for permeation of VOCs across the alveolar lining fluid layer. The project will attempt to solve the three scientific problems: 1) The interfacial chemical mechanisms for impairment of respiratory functions by VOCs; 2) The routes of the availability and fate of VOCs in alveoli; 3) The potentials of impairing the other organs by transportation of VOCs through alveoli lining layer. The prospective results will facilitate to comprehensively recognize the health effects of VOCs, to improve the environmental and health standards and to provide theoretical bases for the prevention of health hazards due to VOCs.

呼吸是挥发性有机物（VOCs）人体暴露的主要途径。肺是VOCs直接危害的首要靶器官和进入人体的入口通道。肺泡液膜层是气-血屏障的主要构成部分，所含肺表面活性物质（PS）是调控肺泡表面张力、维持肺泡稳定、保障正常呼吸的关键物质。界面化学性质是PS功能的物理化学基础。VOCs与PS相互作用可改变PS界面化学性质，进而损伤肺功能，影响肺中VOCs的转运与转化。为查明VOCs与PS相互作用机理及其健康效应，拟从界面化学角度研究：1）VOCs暴露对PS呼吸相关活性的影响；2）VOCs暴露对PS界面化学性质的影响；3）VOCs在肺泡中的多相分配规律；4）VOCs跨肺泡液膜传质作用机理。成果着力解决VOCs损伤呼吸功能的界面化学机理、肺泡中VOCs迁移与归趋途径、VOCs跨肺泡液膜产生全身衍生危害的潜力等科学问题，为明确VOCs暴露与健康效应间因果关系，完善环境卫生标准，防治VOCs危害提供科学依据。

呼吸系统是挥发性有机物(Volatile organic compounds，VOCs)人体暴露的主要途径。一旦进入肺泡区域，VOCs会直接与肺泡气-液界面处（肺泡液膜的最外层）的肺表面性活性物质（Pulmonary surfactant，PS）相接触，PS是调控肺泡表面张力、维持肺泡稳定、保障正常呼吸的关键物质。界面化学性质是PS功能的物理化学基础。VOCs与PS相互作用可改变PS界面化学性质，进而损伤肺功能，影响肺中VOCs的转运与转化。因此，本研究以体外实验为主，通过界面化学方法，探究VOCs与PS间界面化学作用机理。主要研究：VOCs暴露对PS呼吸功能相关活性的影响；VOCs暴露对PS界面化学性质的影响；VOCs在肺泡微环境中的多相分配；VOCs跨肺泡液膜传质机理等四方面内容。通过本项目的实施发现VOCs可以通过改变PS表面张力、相形为等界面性质而具备影响肺功能的潜力，而VOCs对PS膜微观结构的影响是其能改变PS界面性质的关键所在；PS及其活性组分（磷脂和表面活性蛋白）对VOCs都有良好的增溶作用，其中混合磷脂组分PS增溶VOCs的关键组分；PS可以通过对VOCs的增溶作用改变VOCs的生物利用度、影响VOCs在肺泡微环境中的归趋、并增大VOCs的肺毒性；VOCs的跨PS膜传质过程受VOCs本身的性质和PS增溶作用的影响。研究成果将有利于更深入认识VOCs暴露对人体健康的影响机制，从而为VOCs暴露的肺健康风险评估提供界面化学的理论依据。