Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment
Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment
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DOI：
10.1016/j.envint.2006.05.002
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发表时间：
2006-08-01
影响因子：
11.8
通讯作者：
Alonso, Alvaro
中科院分区：
文献类型：
--
作者：
Camargo, Julio A.;Alonso, Alvaro
我们提供了一个全球性的评估，详细的多尺度数据，在水生生态系统中的无机氮污染所产生的生态和毒理学效应。通过对已发表的科学文献的综合分析，我们发现了三个主要的环境问题：（1）它可以增加淡水生态系统中氢离子的浓度，但没有很大的酸中和能力，导致这些系统的酸化;（2）它可以刺激或加强初级生产者的发展、维持和增殖，导致水生生态系统的富营养化;（3）可达致毒性水平，损害水生动物的生存、生长和繁殖能力。地下和地表沃茨的无机氮污染也会对人类健康和经济产生不利影响。由于SO2排放量的减少减少了北美和欧洲大部分地区大气中H2SO 4的沉积，而NOx的排放量却没有得到控制，HNO 3现在在淡水生态系统的酸化中发挥着越来越大的作用。这一酸化过程对初级和次级生产者造成了若干不利影响，在许多大气酸化的湖泊和溪流中造成了重大的生物破坏，特别是对无脊椎动物和鱼类。淡水、河口和沿海海洋生态系统的文化性富营养化可造成与初级生产者的增殖直接或间接相关的生态和毒理学影响。无脊椎动物和鱼类的大量死亡可能是水周转率较低的富营养和过营养水生生态系统中缺氧（或缺氧）最引人注目的表现。溶解氧浓度的下降还可促进还原化合物的形成，如硫化氢，对水生动物造成更严重的不利（毒性）影响。此外，有毒藻类的出现可显著导致水生动物的大量死亡。蓝藻、甲藻和硅藻可能是无机氮污染的主要原因。在水生动物可以直接从环境水中吸收的不同无机含氮化合物（NH 4+、NH 3、NO 2-、HNO 2、NO 3-）中，未离子化的氨毒性最大，而铵离子和硝酸根离子毒性最小。一般来说，海水动物似乎比淡水动物更能耐受无机含氮化合物的毒性，这可能是因为水的盐度（钠、氯、钙和其他离子）对水生动物耐受性的改善作用。从受污染的饮用沃茨中摄入亚硝酸盐和硝酸盐会通过阻断血红蛋白的携氧能力而诱发人类，特别是幼儿的高铁血红蛋白血症。摄入的亚硝酸盐和硝酸盐还可能通过促进亚硝胺的形成而导致消化道癌症的发生。此外，一些科学证据表明，摄入的亚硝酸盐和硝酸盐可能导致致突变性、致畸性和出生缺陷，增加非霍奇金淋巴瘤和膀胱癌和卵巢癌的风险，在胰岛素依赖型糖尿病的病因学和甲状腺肥大的发展中发挥作用，或引起自然流产和呼吸道感染。藻类毒素可间接危害健康，引起恶心、呕吐、腹泻、肺炎、胃肠炎、肝肠炎、肌肉痉挛和几种中毒综合症（麻痹性贝类中毒、神经毒性贝类中毒、失忆性贝类中毒）。无机氮污染与人类传染病（疟疾、霍乱）之间的潜在关系也可能对健康造成其他间接危害。人类的疾病和死亡、水生动物的大量死亡以及其他负面影响可能会增加人类经济的成本，其中娱乐和旅游业受到的经济影响最大，总氮浓度低于0.5-1.0 mg TN/L时，对水生生态系统的影响最大（不包括那些自然氮水平高的生态系统）发展酸化和富营养化，至少是无机氮污染。这些相对较低的总氮水平还可以保护水生动物免受无机含氮化合物的毒性，因为在没有富营养化的情况下，表面沃茨通常存在相对较高浓度的溶解氧，大多数无机活性氮以硝酸盐的形式存在。此外，人类健康和经济将更安全，从无机氮污染的不利影响。(c)2006爱思唯尔有限公司版权所有。
We provide a global assessment, with detailed multi-scale data, of the ecological and toxicological effects generated by inorganic nitrogen pollution in aquatic ecosystems. Our synthesis of the published scientific literature shows three major environmental problems: (1) it can increase the concentration of hydrogen ions in freshwater ecosystems without much acid-neutralizing capacity, resulting in acidification of those systems; (2) it can stimulate or enhance the development, maintenance and proliferation of primary producers, resulting in eutrophication of aquatic ecosystems; (3) it can reach toxic levels that impair the ability of aquatic animals to survive, grow and reproduce. Inorganic nitrogen pollution of ground and surface waters can also induce adverse effects on human health and economy.Because reductions in SO2 emissions have reduced the atmospheric deposition of H2SO4 across large portions of North America and Europe, while emissions of NOx have gone unchecked, HNO3 is now playing an increasing role in the acidification of freshwater ecosystems. This acidification process has caused several adverse effects on primary and secondary producers, with significant biotic impoverishments, particularly concerning invertebrates and fishes, in many atmospherically acidified lakes and streams. The cultural eutrophication of freshwater, estuarine, and coastal marine ecosystems can cause ecological and toxicological effects that are either directly or indirectly related to the proliferation of primary producers. Extensive kills of both invertebrates and fishes are probably the most dramatic manifestation of hypoxia (or anoxia) in eutrophic and hypereutrophic aquatic ecosystems with low water turnover rates. The decline in dissolved oxygen concentrations can also promote the formation of reduced compounds, such as hydrogen sulphide, resulting in higher adverse (toxic) effects on aquatic animals. Additionally, the occurrence of toxic algae can significantly contribute to the extensive kills of aquatic animals. Cyanobacteria, dinoflagellates and diatoms appear to be major responsible that may be stimulated by inorganic nitrogen pollution. Among the different inorganic nitrogenous compounds (NH4+, NH3, NO2-, HNO2, NO3-) that aquatic animals can take up directly from the ambient water, unionized ammonia is the most toxic, while ammonium and nitrate ions are the least toxic. In general, seawater animals seem to be more tolerant to the toxicity of inorganic nitrogenous compounds than freshwater animals, probably because of the ameliorating effect of water salinity (sodium, chloride, calcium and other ions) on the tolerance of aquatic animals. Ingested nitrites and nitrates from polluted drinking waters can induce methemoglobinemia in humans, particularly in young infants, by blocking the oxygen-carrying capacity of hemoglobin.Ingested nitrites and nitrates also have a potential role in developing cancers of the digestive tract through their contribution to the formation of nitrosamines. In addition, some scientific evidences suggest that ingested nitrites and nitrates might result in mutagenicity, teratogenicity and birth defects, contribute to the risks of non-Hodgkin's lymphoma and bladder and ovarian cancers, play a role in the etiology of insulin-dependent diabetes mellitus and in the development of thyroid hypertrophy, or cause spontaneous abortions and respiratory tract infections. Indirect health hazards can occur as a consequence of algal toxins, causing nausea, vomiting, diarrhoea, pneumonia, gastroenteritis, hepatoenteritis, muscular cramps, and several poisoning syndromes (paralytic shellfish poisoning, neurotoxic shellfish poisoning, amnesic shellfish poisoning). Other indirect health hazards can also come from the potential relationship between inorganic nitrogen pollution and human infectious diseases (malaria, cholera). Human sickness and death, extensive kills of aquatic animals, and other negative effects, can have elevated costs on human economy, with the recreation and tourism industry suffering the most important economic impacts, at least locally.It is concluded that levels of total nitrogen lower than 0.5-1.0 mg TN/L could prevent aquatic ecosystems (excluding those ecosystems with naturally high N levels) from developing acidification and eutrophication, at least by inorganic nitrogen pollution. Those relatively low TN levels could also protect aquatic animals against the toxicity of inorganic nitrogenous compounds since, in the absence of eutrophication, surface waters usually present relatively high concentrations of dissolved oxygen, most inorganic reactive nitrogen being in the form of nitrate. Additionally, human health and economy would be safer from the adverse effects of inorganic nitrogen pollution. (c) 2006 Elsevier Ltd. All rights reserved.