NILU - Norwegian Institute for Air Research, P.O. Box 100, 2027 Kjeller, Norway; University of Oslo, 0351 Oslo, Norway.
NILU - Norwegian Institute for Air Research, P.O. Box 100, 2027 Kjeller, Norway.
Ecotoxicol Environ Saf. 2021 Jul 1;217:112172. doi: 10.1016/j.ecoenv.2021.112172. Epub 2021 Apr 16.
National long-term monitoring programs on persistent organic pollutants (POPs) in background air have traditionally relied on active air sampling techniques. Due to limited spatial coverage of active air samplers, questions remain (i) whether active air sampler monitoring sites are representative for atmospheric burdens within the larger geographical area targeted by the monitoring programs, and thus (ii) if the main sources affecting POPs in background air across a nation are understood. The main objective of this study was to explore the utility of spatial and temporal trends in concert with multiple modelling approaches to understand the main sources affecting polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in background air across a nation. For this purpose, a comprehensive campaign was carried out in summer 2016, measuring POPs in background air across Norway using passive air sampling. Results were compared to a similar campaign in 2006 to assess possible changes over one decade. We furthermore used the Global EMEP Multi-media Modeling System (GLEMOS) and the Flexible Particle dispersion model (FLEXPART) to predict and evaluate the relative importance of primary emissions, secondary emissions, long-range atmospheric transport (LRAT) and national emissions in controlling atmospheric burdens of PCB-153 on a national scale. The concentrations in air of both PCBs and most of the targeted OCPs were generally low, with the exception of hexachlorobenzene (HCB). A limited spatial variability for all POPs in this study, together with predictions by both models, suggest that LRAT dominates atmospheric burdens across Norway. Model predictions by the GLEMOS model, as well as measured isomeric ratios, further suggest that LRAT of some POPs are dictated by secondary emissions. Our results illustrate the utility of combining observations and mechanistic modelling approaches to help identify the main factors affecting atmospheric burdens of POPs across a nation, which, in turn, may be used to inform both national monitoring and control strategies.
国家持久性有机污染物（POPs）背景空气的长期监测计划传统上依赖于主动空气采样技术。由于主动空气采样器的空间覆盖范围有限，因此仍然存在以下问题：（i）主动空气采样监测点是否代表监测计划所针对的较大地理区域内的大气负荷，以及（ii）是否了解影响全国背景空气中 POPs 的主要来源。本研究的主要目的是探索空间和时间趋势的实用性，以及多种建模方法，以了解影响全国背景空气中多氯联苯（PCBs）和有机氯农药（OCPs）的主要来源。为此，在 2016 年夏季进行了一项综合运动，使用被动空气采样测量了挪威各地的 POPs。结果与 2006 年的类似运动进行了比较，以评估十年间的可能变化。我们还使用了全球 EMEP 多介质建模系统（GLEMOS）和灵活粒子分散模型（FLEXPART）来预测和评估主要排放、二次排放、长程大气传输（LRAT）和国家排放对控制全国 PCB-153 大气负荷的相对重要性。本研究中，除了六氯苯（HCB）外，大多数目标 OCP 和 PCB 的空气浓度普遍较低。所有 POPs 的空间变异性有限，加上两个模型的预测结果，表明 LRAT 主导了挪威的大气负荷。GLEMOS 模型的预测结果以及测量的同系物比进一步表明，一些 POPs 的 LRAT 受二次排放的控制。我们的结果说明了结合观测和机制建模方法的实用性，以帮助确定影响全国 POPs 大气负荷的主要因素，这反过来又可用于为国家监测和控制战略提供信息。
