Department of Mechanics and Maritime Sciences, Chalmers University of Technology, SE 412 96 Gothenburg, Sweden.
Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
Water Res. 2020 Nov 1;186:116383. doi: 10.1016/j.watres.2020.116383. Epub 2020 Sep 3.
Antifouling paints are biocidal products applied to ship and boat hulls in order to prevent the growth and settlement of marine organisms, i.e. fouling. The release of biocides from the surface of the paint film act to repel or poison potential settling organisms. Currently, the most commonly used biocide in antifouling paints is cuprous oxide. In the EU, antifouling products are regulated under the Biocidal Products Regulation (BPR), which states that the recommended dose should be the minimum necessary to achieve the desired effect. For antifouling products, the dose is measured as the release rate of biocide(s) from coating. In this study, the release rates of copper and zinc from eight different coatings for leisure boats were determined through static exposure of coated panels in four different harbors located in Swedish waters along a salinity gradient ranging from 0 to 27 PSU. The results showed the release rate of copper to increase with increasing salinity. Paints with a higher content of cuprous oxide were also found to release larger amounts of copper. The coatings' ability to prevent biofouling was also evaluated and no significant difference in efficacy between the eight tested products was observed at the brackish and marine sites. Hence, the products with high release rates of copper were equally efficient as those with 4 - 6 times lower releases. These findings suggest that current antifouling paints on the market are leaching copper in excess of the effective dose in brackish and marine waters. Additionally, the results from the freshwater site showed no benefit in applying a copper-containing paint for the purpose of fouling prevention. This indicates that the use of biocidal paints in freshwater bodies potentially results in an unnecessary release of copper. By reducing the release rates of copper from antifouling paints in marine waters and restricting the use of biocidal paints in freshwater, the load of copper to the environment could be substantially reduced.
防污漆是一种应用于船舶船体的杀生产品，用于防止海洋生物的生长和附着，即污损。防污漆漆膜表面释放的杀生剂会排斥或毒害潜在的附着生物。目前，防污漆中最常用的杀生剂是氧化亚铜。在欧盟，防污产品受《杀生产品法规》（BPR）的监管，该法规规定，推荐剂量应是达到预期效果所需的最低剂量。对于防污产品，剂量是通过涂层中杀生剂的释放率来衡量的。在这项研究中，通过在瑞典水域四个不同港口的涂层板进行静态暴露，确定了八种休闲船用涂料中铜和锌的释放率，这些港口的盐度梯度从 0 到 27 PSU 不等。结果表明，铜的释放率随着盐度的增加而增加。还发现，氧化亚铜含量较高的涂料释放出的铜量也较大。还评估了涂层防止生物污损的能力，在半咸水和海水地点，没有观察到八种测试产品之间在功效上有显著差异。因此，释放率高的铜涂料与铜释放率低 4-6 倍的涂料同样有效。这些发现表明，目前市场上的防污漆在半咸水和海水中渗出的铜超过了有效剂量。此外，淡水点的结果表明，为了防止污损，应用含铜涂料没有好处。这表明在淡水体中使用杀生涂料可能会不必要地释放铜。通过降低海洋防污漆中铜的释放率，并限制在淡水体中使用杀生涂料，可以大大减少铜对环境的负荷。
