持久性有机污染物(POPs)在偏远地区大气中的分布与迁移已经成为大气POPs研究的热点.基于被动采样技术的大尺度POPs监测网络已经应用于偏远地区大气POPs的研究之中.其研究成果显示,最近50~60年以来,大气中POPs浓度的最大峰值出现在80年代左右,而80年代之后大气中POPs的浓度日趋减小.这说明各国陆续禁用POPs之后,大气中POPs的浓度有显著降低的趋势.受温度和季节性使用的影响,大气POPs的浓度呈现明显的季节性变化特点:有机氯农药的浓度主要表现为夏季高而冬季低;多环芳烃的浓度则主要表现为冬季高而夏季低.基于POPs高挥发性和长距离大气传输的特点,POPs可以在全球范围内广泛分布,而高海拔地区由于气温较低,使其相对于低海拔地区成为了POPs的“接收器”.大气POPs分布和迁移受温度、降水、气候事件的影响.而且POPs在大气与不同下垫面之间的界面交换的方向、速度和通量也主要受环境温度和POPs的挥发能力的制约.综合大气POPs迁移与气候因素、界面特点之间的关系建立了多介质、大尺度的大气POPs归趋模型.模型的建立和POPs来源的明确使大气POPs传输机制的研究逐渐深入.此外还讨论了目前大气POPs研究中存在着的一些亟待解决的问题,并提出该领域未来可能的发展趋势.
Recently, atmospheric distribution, transport, and reaction of persistent organic pollutants (POPs) in remote areas are getting more attention. Based on the passive air sampler, the networks are established for studying the temporal and spatial distribution of atmospheric POPs in remote areas. The results suggest that the atmospheric concentrations of POPs display a peak value in the 1980s. As the use of POPs has been forbidden after 1980s, concentrations of POPs in air are generally reduced. Concentration of POPs in atmosphere is influenced by temperature and seasonal usage. High concentration of organochlorine pesticides is observed in summer and the comparatively low level is detected in winter. For PAHs, the trend is contrary. High volatility and long-range transport of POPs lead to the global distribution of POPs and accumulation of POPs in remote areas. High mountain is the " acceptor" of atmospheric POPs and cold condensation plays the main role in capturing POPs in high elevation areas. Distribution, transport, exchange direction and exchange flux of POPs among air/water, air/soil, air/ snow and air/vegetation interfaces are mainly controlled by temperature, precipitation and characteristics of POPs. Models were developed on the basis of the effect of these factors. Taken together the transport model and source analysis of POPs, transport mechanism of POPs seems to be clearer. This paper reviewed the progress about the above-mentioned scientific topics and discussed the deficiencies of current researches. Furthermore, it pointed out the further work needed for the study of atmospheric POPs in remote areas.