Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, ON K1A 0H3, Canada.
U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, United States.
Sci Total Environ. 2020 Apr 1;711:135117. doi: 10.1016/j.scitotenv.2019.135117. Epub 2019 Nov 21.
Exposure to methylmercury (MeHg) can result in detrimental health effects in wildlife. With advances in ecological indicators and analytical techniques for measurement of MeHg in a variety of tissues, numerous processes have been identified that can influence MeHg concentrations in wildlife. This review presents a synthesis of theoretical principals and applied information for measuring MeHg exposure and interpreting MeHg concentrations in wildlife. Mercury concentrations in wildlife are the net result of ecological processes influencing dietary exposure combined with physiological processes that regulate assimilation, transformation, and elimination. Therefore, consideration of both physiological and ecological processes should be integrated when formulating biomonitoring strategies. Ecological indicators, particularly stable isotopes of carbon, nitrogen, and sulfur, compound-specific stable isotopes, and fatty acids, can be effective tools to evaluate dietary MeHg exposure. Animal species differ in their physiological capacity for MeHg elimination, and animal tissues can be inert or physiologically active, act as sites of storage, transformation, or excretion of MeHg, and vary in the timing of MeHg exposure they represent. Biological influences such as age, sex, maternal transfer, and growth or fasting are also relevant for interpretation of tissue MeHg concentrations. Wildlife tissues that represent current or near-term bioaccumulation and in which MeHg is the predominant mercury species (such as blood and eggs) are most effective for biomonitoring ecosystems and understanding landscape drivers of MeHg exposure. Further research is suggested to critically evaluate the use of keratinized external tissues to measure MeHg bioaccumulation, particularly for less-well studied wildlife such as reptiles and terrestrial mammals. Suggested methods are provided to effectively use wildlife for quantifying patterns and drivers of MeHg bioaccumulation over time and space, as well as for assessing the potential risk and toxicological effects of MeHg on wildlife.
甲基汞（MeHg）暴露会对野生动物的健康造成有害影响。随着生态指标的进步和分析技术的发展，用于测量各种组织中 MeHg 的方法不断涌现，许多过程已被确定可以影响野生动物体内的 MeHg 浓度。本文综述了测量 MeHg 暴露和解释野生动物体内 MeHg 浓度的理论原理和应用信息。野生动物体内的汞浓度是影响膳食暴露的生态过程与调节吸收、转化和消除的生理过程共同作用的结果。因此，在制定生物监测策略时，应综合考虑生理和生态过程。生态指标，特别是碳、氮和硫的稳定同位素、特定化合物的稳定同位素和脂肪酸，可作为评估膳食 MeHg 暴露的有效工具。动物物种在 MeHg 消除的生理能力上存在差异，动物组织可以是惰性的或具有生理活性的，可以作为 MeHg 的储存、转化或排泄部位，并且在代表 MeHg 暴露的时间上存在差异。年龄、性别、母体转移以及生长或禁食等生物因素也与组织内 MeHg 浓度的解释有关。代表当前或近期生物积累且 MeHg 是主要汞形态的野生动物组织（如血液和卵）最适合用于监测生态系统和了解 MeHg 暴露的景观驱动因素。建议进一步研究，以批判性地评估使用角质化的外部组织来测量 MeHg 生物积累的方法，特别是对于爬行动物和陆生哺乳动物等研究较少的野生动物。本文还提供了一些建议的方法，用于有效地利用野生动物来量化 MeHg 生物积累的时间和空间模式及其驱动因素，以及评估 MeHg 对野生动物的潜在风险和毒理学影响。
