(Table 1) Concentrations of neutral and phenolic organohalogen compounds in adipose tissue, blood, brain and liver of polar bears (Ursus maritimus) from East Greenland@en

The tissue-specific composition of sum classes of brominated and chlorinated contaminants and metabolic/degradation byproducts was determined in adult male and female polar bears from East Greenland. Significantly (p < 0.05) higher concentrations of SUM-PCBs, various other organochlorines such as SUM-CHL, p,p'-DDE, SUM-CBz, SUM-HCHs, octachlorostyrene (OCS),SUM-mirex, dieldrin, the flame retardants SUM-PBDEs, and total-(R)-hexabromocyclododecane (HBCD), SUM-methylsulfonyl (MeSO2)-PCBs and 3-MeSO2-p,p'-DDE, were found in the adipose and liver tissues relative to whole blood and brain. In contrast, SUM-hydroxyl (OH)-PCB, 4-OH-heptachlorostyrene and SUM-OH-PBDE concentrations were significantly highest (p < 0.05) in whole blood, whereas the highest concentrations of SUM-OH-PBBs were found in the adipose tissue. Based on the total concentrations of all organohalogens in all three tissues and blood, the combined body burden was estimated to be 1.34 ± 0.12 g, where >91% of this amount was accounted for by the adipose tissue alone, followed by the liver, whole blood, and brain. These results show that factors such as protein association and lipid solubility appear to be differentially influencing the toxicokinetics, in terms of tissue composition/localization and burden, of organohalogen classes with respect to chemical structure and properties such as the type of halogenation (e.g., chlorination or bromination), and the presence or absence of additional phenyl group substituents (e.g., MeO and OH groups). The tissue- and blood-specific accumulation (or retention) among organohalogen classes indicates that exposure and any potential contaminant-mediated effects in these polar bears are likely tissue or blood specific.本研究测定了东格陵兰岛成年雌雄北极熊体内若干类溴代、氯代污染物及其代谢/降解副产物的组织特异性分布特征。相较于全血与脑组织，脂肪组织和肝脏组织中SUM-多氯联苯（SUM-PCBs）、各类其他有机氯污染物（如SUM-氯代烃类（SUM-CHL）、p,p'-滴滴伊（p,p'-DDE）、SUM-氯苯类（SUM-CBz）、SUM-六氯环己烷类（SUM-HCHs）、八氯苯乙烯（OCS）、SUM-灭蚁灵（SUM-mirex）、狄氏剂（dieldrin））、阻燃剂SUM-多溴二苯醚（SUM-PBDEs）以及总(R)-六溴环十二烷（HBCD）、SUM-甲基磺酰基多氯联苯（SUM-MeSO2-PCBs）与3-甲基磺酰基-p,p'-滴滴伊（3-MeSO2-p,p'-DDE）的浓度均显著更高（p < 0.05）。与之相对，SUM-羟基多氯联苯（SUM-OH-PCB）、4-羟基七氯苯乙烯与SUM-羟基多溴二苯醚（SUM-OH-PBDE）的浓度在全血中显著最高（p < 0.05）；而SUM-羟基多溴联苯（SUM-OH-PBBs）的最高浓度则出现在脂肪组织中。基于三种组织与全血中所有有机卤化物的总浓度，估算得到该种群北极熊的总体内负荷为1.34 ± 0.12 g，其中超过91%的负荷均由脂肪组织单独贡献，其次依次为肝脏、全血与脑组织。研究结果表明，蛋白质结合与脂溶性等因素，会依据化学结构与性质（如卤代类型，即氯代或溴代；是否存在额外苯基取代基，如甲氧基（MeO）与羟基（OH）基团），对不同有机卤化物类别的毒物代谢动力学产生差异化影响，具体体现在组织组成/定位与体内负荷两个方面。各有机卤化物类别的组织与血液特异性蓄积（或滞留）特征表明，这些北极熊所面临的污染物暴露及任何潜在的污染物介导效应，大概率具有组织或血液特异性。