环境中卤代有机污染物的自然来源、背景浓度及形成机理

摘要

Organohalogens are one of the most important pollutants in the environment,of which the environmental chemical behavior,control methods and health effects have aroused great concern around the world,but they are always considered as anthropogenic compounds,such as polychlorinated dibenzo-p-dioxins/ dibenzofurans (PCDDs/Fs),polychlorinated biphenyls (PCBs),polybrominated diphenyl ethers (PBDEs),chlorophenols (CPs) and bromophenols (BPs).Currently,however more and more organohalogens are known to be produced naturally in the environment,and they are widely distributed in the environment,including marine,terrestrial,desert and polar region.Because of their high toxicity,persistence,bioaccumulation potential,and carcinogenicity,and sometimes even acting as environmental hormone substances,the majority of which have a bad effect on human causing mental and psychological harm,most of these pollutants are regulated in many countries.Moreover,natural organohalogens' origin,concentration level,formation mechanism and fate in environment are critical to correctly assess its environmental risk,as well as to set proper enwronmental standards and safe concentration threshold.As research of natural organohalogens is emerging rapidly all over the world,this review summarizes the marine,terrestrial and other sources of natural organohalogens,their physical and chemical properties,and concentration levels of some typical compounds.The formation mechanisms of biotic and abiotic pathways are highlighted.The transport and fate of natural organohalogens in the environment are discussed.Some general analytical methods are also mentioned in this review.The currently research trends and existing questions are prospected,and the formation molecular mechanisms and environmental transport behaviors of natural organohalogens are worthwhile studying.%卤代有机化合物(organohalogens,OHs)是一类典型有机污染物,其环境化学行为、控制方法及健康效应引起了全球的极大关注.目前主要关注人为排放OHs,而其自然来源往往被忽略.最近,环境中卤代有机物的自然来源不断被证实,且检出的OHs数量逐渐增加,但相关研究刚刚起步.卤代有机物的自然来源、背景浓度及其在环境中的迁移转化行为,对于正确评估其污染程度及环境影响、制定相关环境质量标准和系列安全浓度限值至关重要.本文详细归纳总结了卤代有机物的自然来源(包括海洋来源、陆地来源和其他来源等)、背景浓度、理化性质等;重点评述了天然卤代有机化合物(natural organohalogens,NOHs)形成的生物机制、非生物机制及其影响因素;分析了环境中NOHs的迁移转化及归趋行为;最后简介了环境中NOHs的定性与定量分析方法,并展望了未来的研究方向,急需加强天然卤代有机污染物的形成分子机理及环境化学行为的研究工作.