Equilibrium Sampling to Determine the Thermodynamic Potential for Bioaccumulation of Persistent Organic Pollutants from Sediment

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• 作者：Annika Jahnke ; Matthew MacLeod ; H氓kan Wickstr枚m ; Philipp Mayer
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：October 7, 2014
• 年：2014
• 卷：48
• 期：19
• 页码：11352-11359
• 全文大小：396K
• ISSN：1520-5851

文摘

Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (C_Lip鈬孲ed). Furthermore, we evaluated the validity of assumption II by comparing C_Lip鈬孲ed of selected persistent, bioaccumulative and toxic pollutants (polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB)) to lipid-normalized concentrations for a range of biota from a Swedish background lake. PCBs in duck mussels, roach, eel, pikeperch, perch and pike were mostly below the equilibrium partitioning level relative to the sediment, i.e., lipid-normalized concentrations were 鈮?i>C_Lip鈬孲ed, whereas HCB was near equilibrium between biota and sediment. Equilibrium sampling allows straightforward, sensitive and precise measurement of C_Lip鈬孲ed. We propose C_Lip鈬孲ed as a metric of the thermodynamic potential for bioaccumulation of persistent organic chemicals from sediment useful to prioritize management actions to remediate contaminated sites.