Background

Unlike organic pollutants, heavy metals are not created nor are biodegradable materials. They naturally occur in earth crust and many of them reach the environment via anthropogenic activities, which belonged to mining, smelting, production of fertilizers, pesticide applications and others.

Scope and approach

Due to their water solubility and bioaccumulative tendency in different matrices of the environment, some heavy metals are extremely toxic even at low exposure levels and can be transported into the food chain.

Key findings and conclusions

Many criteria are defined to identify heavy metals based on their specific gravity, weight and atomic number, chemical properties and their toxicity, therefore the heavy metals term is still very loose. Dietary exposure is a significant route for trace metals to the humans and constitutes about 90% of exposure. Long term exposure to metals via food consumption, drinking water or other occupational sources leads to serious problems, e.g., hepatotoxicity, kidney failure and neurotoxicity. Analysis of the current situation concluded that the concentrations of heavy metals declined over the years, but they are still hot spots suffering from domestic wastes, agrochemicals like pesticides, fertilizers and industrial wastes. Due to the contamination sources in those hot spots, levels of some metals exceeded the approved permissible limits and become sources of severe problems to humans. Almost comprehensive hazard assessment of these metals is missing due to insufficient data corresponding to body burden for groups potentially exposed to high concentration of metals and their concentrations in foodstuffs.

中文翻译：

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食品中微量金属的发生及其对健康的影响

背景

与有机污染物不同，不会产生重金属，也不是可生物降解的材料。它们自然存在于地壳中，其中许多是通过人为活动到达环境的，这些活动涉及采矿，冶炼，化肥生产，农药施用等。

范围和方法

由于它们在不同环境中的水溶性和生物富集趋势，即使在低暴露水平下，某些重金属也具有极高的毒性，并且可以运输到食物链中。

主要发现和结论

根据重金属的比重，重量和原子序数，化学性质及其毒性，定义了许多标准来识别重金属，因此重金属术语仍然非常宽松。饮食接触是痕量金属进入人体的重要途径，约占暴露的90％。通过食物摄入，饮用水或其他职业来源长期接触金属会导致严重问题，例如肝毒性，肾衰竭和神经毒性。对当前情况的分析得出结论，这些年来重金属的浓度有所下降，但它们仍然是生活垃圾，农药，农药，化肥和工业垃圾等农用化学品的热点地区。由于这些热点中的污染源，一些金属的含量超过了允许的极限，并成为人类严重问题的根源。由于缺乏与可能暴露于高浓度金属及其在食品中的浓度的人群的身体负担相对应的数据不足，因此几乎没有对这些金属进行全面的危害评估。