Bioaccumulation of Metals in Some Fish Species from the Romanian Danube River: A Review

The Danube is the second-largest river in Europe and has been subject to pollution in the past. Additionally, in the last few years, the rapid pace of industrialization and urbanization has led to the inevitable pollution of this aquatic ecosystem by certain metals (essential and non-essential elements). This issue is considered the central problem of pollution in the Danube and is gaining increasing attention. Fish is a good source of proteins, polyunsaturated fatty acids (especially omega-3 fatty acids), essential vitamins, and minerals. Fish are often exposed to metals present in their aquatic environment through direct contact with contaminated water or by consuming organisms that have accumulated metals in their tissues; therefore, the elevated concentrations of metals in water and sediments are reflected in the fish flesh. In this context, the safety of fish and fishery products for human consumption is a public health concern. In the last two decades, more and more reports have shown that Danube River fish are contaminated with metals, causing great concern among consumers. The negative perception continues, although recent scientific studies show that metal levels in the edible parts of the fish are below acceptable limits. The objective of this study was to put together a multitude of scientific research studies that investigate the levels of some metals in various tissues of some fish species with high economic value in the Romanian market, as well as the levels of metals in the water and sediments. The collected data were then utilized to assess the potential health risks posed to humans.