University of Saskatchewan, Toxicology Centre, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; University of Saskatchewan, School of Environment and Sustainability, 117 Science Place, Saskatoon, SK, S7N 5C8, Canada; Canadian Rivers Institute, Canada.
University of Saskatchewan, Toxicology Centre, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
Chemosphere. 2019 Oct;233:381-386. doi: 10.1016/j.chemosphere.2019.05.282. Epub 2019 Jun 1.
Trophic transfer of contaminants dictates concentrations and potential toxic effects in top predators, yet biomagnification behaviour of many trace elements is poorly understood. We examined concentrations of vanadium and thallium, two globally-distributed and anthropogenically-enriched elements, in a food web of the Slave River, Northwest Territories, Canada. We found that tissue concentrations of both elements declined with increasing trophic position as measured by δN. Slopes of log [element] versus δN regressions were both negative, with a steeper slope for V (-0.369) compared with Tl (-0.099). These slopes correspond to declines of 94% with each step in the food chain for V and 54% with each step in the food chain for Tl. This biodilution behaviour for both elements meant that concentrations in fish were well below values considered to be of concern for the health of fish-eating consumers. Further study of these elements in food webs is needed to allow a fuller understanding of biomagnification patterns across a range of species and systems.
污染物的营养转移决定了顶级捕食者体内的浓度和潜在的毒性效应，但许多微量元素的生物放大行为仍未得到充分理解。我们研究了加拿大西北地区斯莱夫河（Slave River）食物网中两种分布广泛且人为富集的元素——钒和铊的浓度。我们发现，这两种元素的组织浓度随着δN（表示营养级）的增加而降低。元素对δN 的对数回归斜率均为负值，钒的斜率（-0.369）比铊的斜率（-0.099）更陡峭。这表明，在食物链中每增加一个环节，钒的浓度会下降 94%，而铊的浓度会下降 54%。这两种元素的这种生物稀释行为意味着鱼类体内的浓度远低于被认为对食用鱼类的消费者健康构成威胁的值。需要进一步研究这些元素在食物网中的分布，以更全面地了解各种物种和系统中的生物放大模式。
