The widely reported increase of terrestrial dissolved organic matter (terrDOM) in northern latitude coastal areas (“coastal darkening”) can impact contaminant dynamics in affected systems. One potential impact is based on differences in chemical adsorption processes of the molecularly larger terrDOM compared to marine DOM (marDOM) that leads to increased emulsification of lipophilic contaminants with terrDOM. Filter feeders filter large amounts of water and DOM daily and thus are directly exposed to associated contaminants through both respiration and feeding activity. Thus, increased exposure to terrDOM could potentially lead to an increase in bioaccumulation of lipid soluble contaminants in filter feeders. To assess the effect of DOM on bioaccumulation in filter feeders, we exposed the mucous based filter feeding ascidian Ciona intestinalis (formerly known as Ciona intestinalis Type B), to the lipophilic veterinary drug teflubenzuron (log KOW: 5.39) in combination with four DOM treatments: TerrDOM, marDOM, a mix of the two called mixDOM, and seawater without DOM addition. The exposure lasted for 15 days, after which the individuals in all DOM treatments showed a trend towards higher bioaccumulation of Teflubenzuron than those in the seawater control. However, there was considerable overlap in posterior distributions. Against our expectations, marDOM resulted in the highest bioaccumulation factor (BAF), followed by mixDOM, with terrDOM resulting in the lowest BAF except for seawater (kinetic BAF L/kg median, 2.5 %–97.5 % percentile marDOM 94, 74–118; mixDOM 82, 63–104; terrDOM 79; 61-99; seawater 61, 44–79). All BAFs were below the level of concern according to the EU REACH regulation (BAF < 2000 L / kg) and, therefore, likely not environmentally problematic in the examined context. However, the results show that DOM can act as a dietary vector; thus, different combinations of contaminants, DOM, and filter feeding organisms should be tested further.

中文翻译：

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DOM 的质量和来源是否会影响脂溶性污染物在滤池喂养海鞘物种 （Ciona） 中的吸收和积累，该物种可以靶向小粒径类别？


广泛报道的北纬沿海地区陆地溶解有机物 （terrDOM） 的增加（“沿海变暗”）会影响受影响系统中的污染物动态。一种潜在影响是基于分子较大的 terrDOM 与海洋 DOM （marDOM） 的化学吸附过程的差异，这导致 terrDOM 对亲脂性污染物的乳化作用增加。滤食性喂食者每天过滤大量的水和 DOM，因此通过呼吸和喂食活动直接暴露于相关污染物中。因此，增加对 terrDOM 的暴露可能会导致滤食性物质中脂溶性污染物的生物积累增加。为了评估 DOM 对滤食性喂食者生物积累的影响，我们将基于粘液的滤食性饲养鞘 Ciona intestinalis（以前称为 Ciona intestinalis B 型）暴露于亲脂性兽药 teflubenzuron （log KOW： 5.39） 与四种 DOM 处理的组合：TerrDOM、marDOM、称为 mixDOM 的两者混合物和不添加 DOM 的海水。暴露持续了 15 天，之后所有 DOM 处理中的个体都显示出比海水对照中的个体更高的 Teflubenzuron 生物积累趋势。然而，后验分布存在相当大的重叠。出乎我们的预期，marDOM 导致最高的生物积累因子 （BAF），其次是 mixDOM，除海水外，terrDOM 导致最低的 BAF（动力学 BAF L/kg 中位数，2.5 %–97.5% 百分位 marDOM 94， 74–118;mixDOM 82， 63–104;terrDOM 79;61-99;海水 61， 44–79）。 根据欧盟 REACH 法规（BAF < 2000 L / kg），所有 BAF 均低于关注级别，因此在审查环境中可能没有环境问题。然而，结果表明 DOM 可以作为饮食媒介;因此，应进一步测试污染物、DOM 和滤食性生物的不同组合。