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1. Introduction
Morgan [1] noted that heavy metal contamination of foods may occur at various stages of production, from growth to consumption. Sources and toxicity of heavy metals and mechanisms of their uptake by microorganisms and bioremediation have been widely discussed [2,3,4,5,6,7,8,9,10,11]. However, heavy metals are indestructible, and therefore can concentrate in the food chain and eventually accumulate in the human body [2,12]. Filipiak-Florkiewicz et al. [13] mentioned that neuroendocrine disruptions caused by heavy metals and other organic pollutants can be associated with their neurotoxicity and obesity prevalence.
In contaminated soil and water, the following elements can occur: arsenic, cadmium, chromium, mercury, lead, and zinc [12]. Tóth et al. stated that in the European Union (EU) countries, concentrations of heavy metals in soils are relatively-but not alarmingly-high [14]; however, they suggested that Western European soils should be assessed and monitored in detail [15]. Bao et al. [16] reported that the concentrations of mercury, lead, and copper should be monitored in areas that are engaged in treated sewage irrigation, in order to prevent these heavy metals from entering the food chain and presenting a health risk. Similarly, Hassan et al. [17] mentioned that regular monitoring of heavy metals from industrial and domestic effluents, irrigation waters, and crops is essential to preventing their excessive accumulation in the food chain. Wang et al. [18] also drew attention to the necessity of regular monitoring of heavy metal contamination in crops grown in wastewater-irrigated sites, adding that wastewater technology should be perfected to improve the removal of heavy metals. In turn, Islam et al. [19] stated that agronomic practices such as fertilizers, water management, and crop rotation can affect the bioavailability and crop accumulation of heavy metals. Solanki and Dhankhar [20] suggested that understanding the mechanisms by which plants defend themselves against heavy metal stress could be helpful in the generation and selection of heavy metal-tolerant plants, which could be grown in fields containing high levels of heavy metals and intended for human consumption.
However, the prevalence of heavy metals in the aquatic environment is noticed particularly often. Fish generally accumulate heavy metal contaminants [21,22]. Jakimska et al. [23] noted that the harmfulness of heavy metals to marine organisms-resulting from bioaccumulation in tissues and organs-relates not only to the extent...