Global Monitoring Program for Understanding the Fate of Persistent Man-Made Chemicals in the Tropical Environment

为了阐明PCBs、DDTs和BHCs等持久性有机氯的综合行为，本研究在亚洲热带和亚热带陆地和海岸环境中进行。此外，本研究还描述了有机氯在热带环境中的归趋及其全球影响，根据调查的西北太平洋和南太平洋和印度洋。结果表明：（1）亚洲热带地区的环境样品中有机氯杀虫剂的污染程度高于工业用多氯联苯。然而，在城市地区的各种样品中观察到大量的多氯联苯污染，这表明即使在热带国家，多氯联苯的使用也逐渐广泛。 ...更多信息 在温带地区，这两个地区空气中的浓度水平相当。热带稻田施用六六六试验和流域六六六通量模拟结果表明，施用的杀虫剂在很大程度上迅速向大气迁移，热带地区对全球环境的影响更大。3）同时，远离源头的北太平洋沃茨和极地海域也记录到了相当高的六六六浓度。BHC在空气和水之间的质量迁移计算表明，BHC有很强的从空气向水迁移的趋势，这意味着北太平洋北方及其附近的极地沃茨可能是BHC的汇之一，可以说热带地区使用的持久性人造化学品有大量释放到大气中。它们通过“远距离大气输运”在全球范围内扩散，并最终存款到像北太平洋北方这样的汇中。还应从生态毒理学的角度考虑这种汇，因为它们在残留物的生物累积和对常驻海洋生物的毒性表现方面可能发挥重要作用。少

In order to elucidate the comprehensive behavior of persistent organochlorines such as PCBs, DDTs and BHCs, the present investigation has been undertaken in the terrestrial and coastal environments of tropical and subtropical Asia. Beside this, the fate of organochlorines in the tropical environment and its global implications are also described in the present study, based on the survey of western North and South Pacific and Indian oceans. Consequently, the following results were obtained :1) The environmental samples from tropical Asia revealed more prominent contamination by organochlorine insecticides rather than PCBs which were mainly used for industrial purposes. However, considerable PCB contamination was observed in various samples from urban areas, suggesting the gradual widespread usage of PCBs even in tropical countries.2) It was generally observed that the residue levels of organochlorine insecticides in soil and sediments were found to be much lower in tropical regions than … More in temperate ones, whereas those levels in air were comparable in both regions. According to the application test of BHC in the tropical paddy field and flux modeling of it in watershed, it was noted that the applied insecticides were rapidly transported to atmosphere to a large extent, suggesting the tropical regions have a greater impact on the global environment.3) At the same time, considerable BHC levels were recorded in the oceanic waters off Norther Pacific and polar regions, far away from the source. The calculations of mass transfer of BHCs between air and water revealed that BHC has a strong tendency to transfer from air to water, implying that northern North Pacific and nearby polar waters may play a role as one of the sink for such contaminants.On the whole, it could be said that large quantities of persistent man-made chemicals used in the tropics are released into the atmosphere. They disperse through "long-range atmospheric transport" on global terms and ultimately deposit into the sink like northern North Pacific. Such a sink should also be considered in ecotoxicological perspective as they may play a major role in the bioaccumulation of residues and toxic manifestation to resident marine organisms. Less