Institute of Environmental Systems Research, University of Osnabrück, Germany.
Environ Sci Technol. 2011 Dec 1;45(23):10075-81. doi: 10.1021/es2012534. Epub 2011 Oct 28.
Screening of long-range transport potential (LRTP) of organic chemicals in water requires the development of criteria in analogy to the existing LRTP criteria for airborne chemicals. According to the Stockholm Convention, compounds mainly partitioning into air are assumed to be prone to LRTP if they have a half-life in air of more than two days. Using mean flow velocities of European rivers (0.7-1 m/s) and of ocean currents running into the Arctic Ocean (0.28-0.9 m/s), we derived corresponding half-life criteria for freshwater and seawater (10 days and 90 days, respectively). Next, we calculated the characteristic travel distance (CTD) of several thousand chemicals from the Canadian Domestic Substances List (DSL) and all current POPs using the multimedia model ELPOS. This shows that the CTD in water dominates the CTD in air only for chemicals that are characterized by a large half-life in water and a low air-water partition coefficient (about 38% of the nonionic organic substances selected from the DSL). In particular, there are substances that are not classified as persistent compounds in water but exhibit higher CTDs for transport in water than for transport in air. Finally, we evaluated whether the LRTP boundary derived from POP reference chemicals has to be revised if LRTP in water is included and found that this boundary can be applied to all organic chemicals regardless of their transport in air or water.
水质中长距离迁移潜力（LRTP）的筛选需要制定类似于现有空气化学物质 LRTP 标准的标准。根据《斯德哥尔摩公约》，如果化合物主要分配到空气中，且其在空气中的半衰期超过两天，则假定其易于长距离迁移。利用欧洲河流（0.7-1 m/s）和流入北冰洋的海流（0.28-0.9 m/s）的平均流速，我们得出了淡水和海水的相应半衰期标准（分别为 10 天和 90 天）。接下来，我们使用多媒体模型 ELPOS 计算了来自加拿大国内物质清单（DSL）和所有当前持久性有机污染物的数千种化学物质的特征迁移距离（CTD）。这表明，只有当水中的化学物质具有较长的半衰期和较低的气-水分配系数（约占 DSL 中选择的非离子有机物质的 38%）时，水中的 CTD 才会主导空气中的 CTD。特别是，有些物质在水中不被归类为持久性化合物，但在水中的迁移 CTD 高于空气中的迁移 CTD。最后，我们评估了如果将水中的 LRTP 包括在内，是否需要修订源自持久性有机污染物参考化学物质的 LRTP 边界，并发现该边界可适用于所有有机化学物质，无论其在空气中还是水中的迁移情况如何。
