Pradel Alice, Hufenus Rudolf, Schneebeli Martin, Mitrano Denise M
Institute of Biogeochemistry and Pollutant Dynamics (IBP), Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland.
Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory of Advanced Fibers, St. Gallen, Switzerland.
Nat Commun. 2025 May 12;16(1):4375. doi: 10.1038/s41467-025-59608-2.
Sea ice accumulates contaminants and redistributes them laterally as the ice drifts and vertically as it melts. Contaminant incorporation into sea ice must be better understood to resolve contaminant cycling and exposure to polar organisms. Here we develop an experimental method that mimics the formation of young sea ice and enables the quantification of model contaminants separately in the ice matrix and brine. Several limitations inherent in field studies are overcome using this approach. Results show that dissolved contaminants (<1 nm) and dispersed colloidal contaminants (1 nm-1 μm) follow the same behavior as sea salts. When colloids aggregate they follow a similar transport pathway to high-density particulate contaminants (>1 μm). While high-density particles are depleted in sea ice and low-density particles are enriched relative to their initial concentration in seawater, both are engulfed and can travel in wide brine channels. These results can also help to predict the incorporation of natural species in sea ice.
海冰会积累污染物，并在其漂移时进行横向再分配，在融化时进行纵向再分配。为了解决污染物循环和极地生物暴露问题，必须更好地理解污染物在海冰中的掺入情况。在这里，我们开发了一种实验方法，该方法模拟年轻海冰的形成，并能够分别对冰基质和盐水中的模型污染物进行定量。使用这种方法克服了实地研究中固有的几个局限性。结果表明，溶解污染物（<1纳米）和分散胶体污染物（1纳米 - 1微米）与海盐的行为相同。当胶体聚集时，它们遵循与高密度颗粒污染物（>1微米）相似的传输途径。虽然相对于它们在海水中的初始浓度，高密度颗粒在海冰中减少，低密度颗粒在海冰中富集，但两者都会被吞没并可以在宽阔的盐水通道中移动。这些结果也有助于预测天然物种在海冰中的掺入情况。
