Scheuhammer A M
Environment Canada, Canadian Wildlife Service, 100 Gamelin Blvd, Ottawa, Ontario, Canada K1A OH3.
Environ Pollut. 1991;71(2-4):329-75. doi: 10.1016/0269-7491(91)90036-v.
The effects of acidification on wildlife inhabiting aquatic or semi-aquatic environments are reviewed, with particular reference to the possibility for increased dietary exposure to Hg, Cd, Pb and/or Al, and decreased availability of essential dietary minerals such as Ca. It is concluded that: (1) piscivores risk increased exposure to dietary methyl-Hg in acidified habitats, and Hg concentrations in prey may reach levels known to cause reproductive impairment in birds and mammals; (2) piscivores do not risk increased exposure to dietary Cd, Pb or Al because these metals are either not increased in fish due to acidification, or increase are trivial from a toxicological perspective; (3) insectivores and omnivores may, under certain conditions, experience increased exposure to toxic metals in some acidified environments. Exposure levels are likely to be sufficiently low, however, that significant risks to health or reproduction are unlikely. More importantly, these wildlife species may experience a drastic decrease in the availability of dietary Ca due to the pH-related extinction of high-Ca aquatic invertebrate taxa (molluscs, crustaceans). Decreased availability of dietary Ca is known to adversely affect egg laying and eggshell integrity in birds, and the growth of hatchling birds and neonatal mammals. Acidification-related changes in the dietary availability of other essential elements, such as Mg, Se and P, have not been established and require further investigation; (4) herbivores may risk increased exposure to Al and Pb, and perhaps Cd, in acidified environments because certain macrophytes can accumulate high concentrations of these metals under acidic conditions. The relative importance of pH in determining the metal concentrations of major browse species, and the toxicological consequences for herbivores wildlife, is not well established and requires further study. A decreased availability of dietary Ca is also likely for herbivores inhabiting acidified environments.
本文综述了酸化对栖息在水生或半水生环境中的野生动物的影响，特别提及了因饮食导致汞、镉、铅和/或铝摄入量增加的可能性，以及必需饮食矿物质（如钙）的可利用性降低的情况。研究得出以下结论：（1）在酸化栖息地中，食鱼动物面临饮食中甲基汞暴露增加的风险，猎物中的汞浓度可能达到已知会导致鸟类和哺乳动物生殖功能受损的水平；（2）食鱼动物不会面临饮食中镉、铅或铝暴露增加的风险，因为这些金属不会因酸化而在鱼类中增加，或者从毒理学角度来看增加量微不足道；（3）在某些条件下，食虫动物和杂食动物在一些酸化环境中可能会增加有毒金属的暴露。然而，暴露水平可能足够低，不太可能对健康或繁殖构成重大风险。更重要的是，由于高钙水生无脊椎动物类群（软体动物、甲壳类动物）因pH值相关原因灭绝，这些野生动物物种的饮食中钙的可利用性可能会大幅下降。已知饮食中钙的可利用性降低会对鸟类的产卵和蛋壳完整性以及雏鸟和新生哺乳动物的生长产生不利影响。与酸化相关的其他必需元素（如镁、硒和磷）在饮食中的可利用性变化尚未确定，需要进一步研究；（4）在酸化环境中，食草动物可能面临铝和铅，或许还有镉暴露增加的风险，因为某些大型植物在酸性条件下会积累高浓度的这些金属。pH值在决定主要食草物种金属浓度方面的相对重要性以及对食草野生动物的毒理学后果尚未明确，需要进一步研究。生活在酸化环境中的食草动物的饮食中钙的可利用性也可能降低。
