Accumulation of Heavy Metals in Fish: A Serious Threat to Food Security and Public Health

The spread of pollutants, including heavy metals, in water resources, has negatively affected many marine and freshwater ecosystems and, consequently, their habitats, especially fish. Since the fisheries industry provides part of the food needs of society, the transfer of pollutants such as heavy metals through the food chain to the human body can be considered a threat to the health of human society. Therefore, the need to study this issue is felt like one of the research needs at the national and international levels.This narrative review examines the subject by reviewing library resources, articles, books, as well as reputable scientific databases. In this review, first, a perspective of the fisheries and aquaculture industry was presented and then, the accumulation of heavy metals in the tissues of fish and their transfer to the human food chain was considered. Also, the major effects of heavy metals on human health were investigated.In general, most heavy metals are toxic to the body at very low levels. However, among the studied metals, mercury, lead, and cadmium have a higher degree of toxicity, therefore, increasing these heavy metals in fish tissue to more than the allowable level is associated with many risks. The main mechanism of toxicity of heavy metals involves the production of free radicals to cause oxidative stress, which causes damage to biological molecules such as enzymes, proteins, nucleic acids, and DNA.Based on the results, increasing the levels of mercury, lead and cadmium in fish tissue compared to other metals can have more harmful effects on public health. Therefore, it is necessary to closely monitor the quality of consumables, especially fish sold in wholesale markets and retailers.