Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, Canada; Wildlife Conservation Society Canada, Thunder Bay, Toronto, ON, Canada.
Cooperative Freshwater Ecology Unit, Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, Canada; Ontario Ministry of Natural Resources and Forestry, Sudbury, ON, Canada.
Environ Pollut. 2020 Apr;259:113878. doi: 10.1016/j.envpol.2019.113878. Epub 2019 Dec 31.
Eating fish provides numerous health benefits, but it is also a dominant pathway for human exposure to contaminants. Many studies have examined mercury (Hg) accumulation in fish, but fewer have considered other elements, such as arsenic (As) and chromium (Cr). Recently, freshwater fish from several pristine boreal systems across northern Ontario, Canada, have been reported with elevated concentrations of As and Cr for reasons that are not well understood. Our goal was to investigate the ecological and environmental influences over concentrations of As, Cr, and other elements in these fish to better understand what affects metal uptake and the risk to consumers. We measured 10 elements (including As, Cr, Hg) as well as carbon (δC), nitrogen (δN), and sulfur (δS) stable isotopes in 388 fish from 25 lake and river sites across this remote region. These data were used to determine the effect of: 1) trophic ecology; and 2) watershed geology on piscine elemental content. Overall, most element concentrations were low, often below provincial advisory benchmarks (ABs). However, traces of Hg, As, Cr, and selenium (Se) were detected in most fish. Based on their exceedance of their respective ABs, the most restrictive elements on fish consumption in these boreal systems were Hg > As > Cr. Arsenic and Se, but not Cr concentrations were related to fish size and trophic ecology (inferred from δC and δN), suggesting bioaccumulation of the former elements. Fish with enriched δS values, suggestive of anadromous behaviour, had marginally lower Hg but higher Se concentrations. Modeling results suggested a strong effect of site-specific factors, though we found weak trends between piscine elemental content and geological features (e.g., mafic intrusions), potentially due to the broad spatial scale of this study. Results from this study address gaps in our understanding of As and Cr bioaccumulation and will help to inform fish consumption guidelines.
吃鱼有很多好处，但它也是人类接触污染物的主要途径之一。许多研究都考察了鱼类体内的汞（Hg）积累情况，但对其他元素，如砷（As）和铬（Cr）的研究较少。最近，加拿大安大略省北部几个原始北方地区的淡水鱼报告显示，其体内的 As 和 Cr 浓度升高，但其原因尚不清楚。我们的目标是研究这些鱼类中 As、Cr 和其他元素的浓度受生态和环境的影响，以更好地了解哪些因素会影响金属的吸收以及对消费者的风险。我们测量了 388 条鱼的 10 种元素（包括 As、Cr、Hg）以及碳（δC）、氮（δN）和硫（δS）稳定同位素，这些鱼来自该偏远地区的 25 个湖泊和河流地点。这些数据用于确定以下因素的影响：1）营养生态学；2）流域地质对鱼类元素含量的影响。总体而言，大多数元素浓度较低，通常低于省级咨询基准（AB）。然而，大多数鱼体内都检测到痕量的 Hg、As、Cr 和硒（Se）。根据它们各自 AB 的超标情况，这些北方系统中对鱼类消费最具限制性的元素是 Hg>As>Cr。砷和硒，而不是 Cr 的浓度与鱼类大小和营养生态有关（根据 δC 和 δN 推断），这表明前两种元素的生物积累。δS 值丰富的鱼类，提示其具有溯河洄游行为，其 Hg 含量略低，但 Se 含量较高。模型结果表明，特定地点因素的影响很大，但我们发现鱼类元素含量与地质特征（如镁铁质侵入体）之间存在微弱的趋势，这可能是由于本研究的空间尺度较大。本研究的结果解决了我们对 As 和 Cr 生物积累的理解中的空白，并将有助于为鱼类消费指南提供信息。
