Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, CanadaM1C 1A4.
Environ Sci Process Impacts. 2017 Aug 16;19(8):1000-1015. doi: 10.1039/c7em00167c.
For Canadian Arctic indigenous populations, marine mammal (MM) traditional foods (TFs) represent sources of both important nutrients and hazardous environmental contaminants. Food preparation is known to impact the nutrient and environmental contaminant content of processed items, yet the impacts of preparation on indigenous Arctic MM TFs remain poorly characterized. In order to determine how the various processes involved in preparing beluga blubber TFs affect their levels of nutrients and environmental contaminants, we collected blubber samples from 2 male beluga whales, aged 24 and 37 years, captured during the 2014 summer hunting season in Tuktoyaktuk, Northwest Territories, and processed them according to local TF preparation methods. We measured the levels of select nutrients [selenium (Se), polyunsaturated fatty acids (PUFAs)] and contaminants [organochlorine pesticides, perfluoroalkyl and polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), mercury (Hg)] in raw and prepared (boiled, roasted, aged) beluga blubber TFs. The impacts of beluga blubber TF preparation methods on nutrient and environmental contaminant levels were inconsistent, as the majority of processes either did not appear to influence concentrations or affected the two belugas differently. However, roasting and ageing beluga blubber consistently impacted certain compounds: roasting blubber increased concentrations of hydrophilic substances (Se and certain PFASs) through solvent depletion and deposited PAHs from cookfire smoke. The solid-liquid phase separation involved in ageing blubber depleted hydrophilic elements (Se, Hg) and some ionogenic PFASs from the lipid-rich liquid oil phase, while PUFA levels appeared to increase, and hydrophobic persistent organic pollutants were retained. Ageing blubber adjacent to in-use smokehouses also resulted in considerable PAH deposition to processed samples. Our findings demonstrated that contaminant concentration differences were greater between the two sets of whale samples, based on age differences, than they were within each set of whale samples, due to variable preparation methods. When considering means to minimize human contaminant exposure while maximizing nutrient intake, consumption of aged liquid from younger male whales would be preferred, based on possible PUFA enhancement and selective depletion of hydrophilic environmental contaminants in this food item.
对于加拿大北极地区的土著居民来说，海洋哺乳动物（MM）传统食物（TFs）是重要营养物质和有害环境污染物的来源。人们知道，食物的制备会影响加工食品中的营养物质和环境污染物的含量，但关于制备过程对土著北极 MM TFs 的影响仍知之甚少。为了确定制备白鲸鲸脂 TF 时涉及的各种过程如何影响其营养物质和环境污染物的水平，我们从 2 只雄性白鲸身上采集了鲸脂样本，它们分别在 2014 年夏季在西北地区图克托亚图克被捕获，年龄分别为 24 岁和 37 岁，并按照当地 TF 制备方法对其进行了处理。我们测量了选定的营养物质[硒（Se），多不饱和脂肪酸（PUFAs）]和污染物[有机氯农药，全氟烷基和多氟烷基物质（PFASs），多溴二苯醚，多氯联苯，多环芳烃（PAHs），汞（Hg）]在生的和制备的（煮沸，烘烤，陈化）白鲸鲸脂 TF 中的含量。白鲸鲸脂 TF 制备方法对营养物质和环境污染物水平的影响不一致，因为大多数过程似乎都没有影响浓度，或者对这两只白鲸的影响不同。但是，烘烤和陈化白鲸鲸脂会一致地影响某些化合物：烘烤鲸脂通过溶剂耗尽增加了亲水性物质（Se 和某些 PFASs）的浓度，并从炊火烟雾中沉积了 PAHs。老化鲸脂中固液相分离从富含脂质的液体油相中耗尽了亲水性元素（Se、Hg）和某些离子型 PFASs，而 PUFA 水平似乎增加了，而疏水性持久性有机污染物则被保留。老化的鲸脂与正在使用的烟熏房相邻，也导致处理样品中 PAH 的大量沉积。我们的研究结果表明，基于年龄差异，两组鲸鱼样本之间的污染物浓度差异大于每组鲸鱼样本之间的差异，这是由于制备方法的不同。在考虑最大限度地减少人类污染物暴露并最大限度地增加营养物质摄入的方法时，基于这种食物中可能的 PUFA 增强和亲水性环境污染物的选择性耗尽，年轻雄性鲸鱼的老化液体的消耗将是首选。
