Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, Nanaimo, V9R 5S5, British Columbia, Canada; Department of Chemistry, University of Victoria, Victoria, V8P 5C2, British Columbia, Canada.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
Chemosphere. 2024 Jul;359:142315. doi: 10.1016/j.chemosphere.2024.142315. Epub 2024 May 10.
The fate and distribution of environmental contaminants includes bioaccumulation within marine organisms. A deceased 4-m long adult female bluntnose sixgill shark, pregnant with 72 pups, was recovered from Coles Bay on Vancouver Island, BC, Canada in 2019. This specimen provided a unique opportunity to examine maternal transfer of contaminants in a yolk-sac viviparous shark species. Liver subsamples of the adult and offspring were analyzed for 18 targeted inorganic elements by inductively coupled plasma optical emission spectroscopy (ICP-OES) and 21 targeted perfluoroalkyl substances (PFAS) by liquid chromatography-electrospray ionization-high resolution mass spectrometry (LC-ESI-Orbitrap MS). The maternal-offspring transfer efficiencies in liver tissue were subsequently examined for both contaminant classes. Concentrations of all detectable metals apart from calcium and magnesium were found to be higher in the mother compared to the offspring, including substantial levels of toxic cadmium (6 ± 2 mg kg dw) and lead (7 ± 3 mg kg dw). Conversely, high maternal transfer efficiencies were observed for PFAS (i.e., ΣPFAS = 71 ± 9 ng g ww in offspring compared to 13 ± 9 ng g ww in the mother). This study highlighted the unique maternal transfer characteristics of PFAS in bluntnose sixgill sharks depending on the structure of the polar head group, with greater liver-to-liver transfer efficiencies observed for perfluorocarboxylic acids (PFCAs) than perfluorosulfonic acids (PFSAs) of the same fluorocarbon chain length.
环境污染物的命运和分布包括在海洋生物体内的生物积累。2019 年，在加拿大不列颠哥伦比亚省温哥华岛的科尔斯湾，人们从一条长 4 米的成年雌性宽吻六鳃鲨尸体中发现了 72 只幼鲨。这具标本为研究蛋黄囊胎生鲨鱼物种中污染物的母体转移提供了一个独特的机会。对成年鲨鱼及其后代的肝脏进行了分析，采用电感耦合等离子体光学发射光谱法（ICP-OES）分析了 18 种目标无机元素，采用液相色谱-电喷雾电离-高分辨质谱法（LC-ESI-Orbitrap MS）分析了 21 种目标全氟烷基物质（PFAS）。随后检查了这两类污染物在肝脏组织中的母体向后代的转移效率。除了钙和镁之外，所有可检测金属的浓度在母体中都高于后代，包括大量有毒的镉（6±2mg kg dw）和铅（7±3mg kg dw）。相反，PFAS 的母体转移效率很高（即，后代中的ΣPFAS=71±9ng g ww，而母亲中的含量为 13±9ng g ww）。本研究强调了 PFAS 在宽吻六鳃鲨中的独特母体转移特征取决于极性头基团的结构，具有相同氟碳链长度的全氟羧酸（PFCAs）比全氟磺酸（PFSAs）具有更高的肝-肝转移效率。
