Owing to their toxicity, persistence and capacity for long-range atmospheric transport, persistent organic pollutants (POPs) are internationally regulated. However, forests can uptake and sequester POPs from the atmosphere, acting as a filter as they are transported to the poles as part of the so-called grasshopper effect. In this Review, we summarize POP (and polyaromatic hydrocarbon) cycling and distribution in forests, and discuss the environmental factors that impact POP fates. Pollutants are taken up by foliage and transported to the forest floor, where they can be stored in the litter layer or leach further into the soil. Typically, soil organic carbon content, temperature and latitude are the most important factors influencing POP distribution and storage, with boreal and tropical forests accumulating the greatest POP concentrations. Forest fires and deforestation, however, threaten the ability of forests to sequester POPs, with the former also anticipated to increase production of POPs and polyaromatic hydrocarbons through combustion. In order to better estimate the burden of POPs in the environment, greater large-scale and long-term observations are required in all forests, particularly in tropical regions and the Southern Hemisphere.

由于其毒性，持久性和远距离大气迁移的能力，持久性有机污染物（POPs）在国际上受到监管。但是，森林可以从大气中吸收和隔离持久性有机污染物，作为所谓的蚱effect效应的一部分，它们被运输到两极时起到过滤作用。在本综述中，我们总结了POP（和聚芳烃）在森林中的循环和分布，并讨论了影响POP命运的环境因素。污染物被树叶吸收，并被运送到森林地面，在那里它们可以存储在垃圾层中或进一步浸入土壤中。通常，土壤有机碳含量，温度和纬度是影响持久性有机污染物分布和存储的最重要因素，而北方和热带森林的持久性有机污染物浓度最高。然而，森林大火和森林砍伐威胁着森林隔离持久性有机污染物的能力，前者还有望通过燃烧增加持久性有机污染物和多环芳烃的生产。为了更好地估计环境中持久性有机污染物的负担，需要在所有森林中，特别是在热带地区和南半球，进行更大范围的长期观测。