Environ Sci Technol. 2011 Mar 15;45(6):2107-15. doi: 10.1021/es1038529. Epub 2011 Feb 22.
Polychlorinated biphenyl (PCB) congener patterns based on full congener PCB analyses of three farmed and five wild species of salmon from coastal British Columbia, Canada are compared using principal components analysis (PCA) and the best fit linear decomposition of the observed PCB composition in terms of Aroclor 1242, 1254, and 1260 end-members. The two complementary analysis methods are used to investigate congener composition pattern differences between species, trophic levels, feeding preferences, and farmed or wild feeding regimes, with the intent of better understanding PCB processes in both salmon and salmon consumers. PCA supports classification of PCB congeners into nine groups based on a) structure activity groups (SAG) related to the bioaccumulation potential in fish-eating mammals, b) Cl number, and c) the numbers of vicinal meta- and para-H. All three factors are needed to interpret congener distributions since SAGs by themselves do not fully explain PCB distributions. Farmed salmon exhibit very similar congener patterns that overlap the PCA and Aroclor composition of their food, while wild salmon separate into two distinct groups, with chinook and "coastal" coho having higher proportions of the higher chlorinated, Aroclor 1260 type, nonmetabolizable congeners, and chum, pink, sockeye, and "remote" coho having higher proportions of the lower chlorinated, more volatile and metabolizable Aroclor 1242 type, congeners. Wild chinook have the highest PCB and toxic equivalent (TEQ) concentrations, and the highest proportions of A1254 A1260, and PCB congeners in the most refractory SAG. Because both "coastal" and "remote" coho groups are likely to be consuming prey of similar size and trophic level, the PCB delivery mechanism (e.g., atmosphere vs runoff) apparently has more influence on the salmon PCB profile than biotransformation, suggesting that the wild chinook PCB profile is determined by feeding preference. Overall, wild salmon distributions primarily relate to trophic level, feeding preferences, and longevity, while metabolism appears at most a minor factor. The new classification protocol takes better advantage of individual congener PCB analyses and provides a better framework for understanding the PCB distributions in salmon and, potentially, the movement of individual PCB congeners through marine food chains than previous classification schemes.
多氯联苯（PCB）同系物模式基于对来自加拿大不列颠哥伦比亚省沿海地区的三种养殖和五种野生三文鱼的全同系物 PCB 分析，使用主成分分析（PCA）和最佳拟合线性分解，根据 Aroclor 1242、1254 和 1260 端元来观察 PCB 成分。这两种互补的分析方法用于研究物种、营养水平、摄食偏好、养殖或野生摄食方式之间同系物组成模式的差异，旨在更好地了解三文鱼和三文鱼消费者体内的 PCB 过程。PCA 支持根据以下三个因素将 PCB 同系物分为九组：a）与鱼类哺乳动物生物蓄积潜力相关的结构活性组（SAG），b）氯原子数，以及 c）邻位间和对位间 H 的数量。由于 SAG 本身并不能完全解释 PCB 分布，因此需要这三个因素来解释同系物的分布。养殖三文鱼表现出非常相似的同系物模式，与它们食物的 PCA 和 Aroclor 组成重叠，而野生三文鱼则分为两个不同的群体，奇努克和“沿海”银鲑的更高比例为高氯化、Aroclor 1260 型、不可代谢的同系物，而红鲑、粉鲑、红鲑和“偏远”银鲑的更高比例为低氯化、更易挥发和可代谢的 Aroclor 1242 型同系物。野生奇努克三文鱼的 PCB 和毒性当量（TEQ）浓度最高，且最具抗性的 SAG 中 A1254 A1260 和 PCB 同系物的比例最高。由于“沿海”和“偏远”银鲑组可能都在摄食大小和营养水平相似的猎物，因此，与生物转化相比，三文鱼 PCB 特征的输送机制（例如，大气与径流）显然对三文鱼 PCB 特征的影响更大，这表明野生奇努克三文鱼 PCB 特征是由摄食偏好决定的。总体而言，野生三文鱼的分布主要与营养水平、摄食偏好和寿命有关，而代谢似乎只是一个次要因素。与之前的分类方案相比，新的分类方案更好地利用了个体 PCB 同系物分析，并为理解三文鱼体内的 PCB 分布以及潜在的单个 PCB 同系物在海洋食物链中的迁移提供了更好的框架。
