Characteristics and risk assessment of heavy metal accumulation during aquaculture in northern Anhui Province, China

In order to investigate the concentration characteristics of heavy metals in aquaculture environments and fish, 54 samples were collected in 2023 from northern Anhui, China. The dynamics of seven trace elements in water, sediment, and fish were analyzed throughout the aquaculture cycle. Sources of heavy metals were identified through correlation analysis and principal component analysis (PCA). Additionally, human health risk assessment models were employed to evaluate the potential risks associated with fish consumption across different age groups. The findings of the study indicated that the concentrations of seven heavy metals in both water and sediments exhibited varying degrees of increase throughout the culture period. Notably, the increases in Zn and Pb in the water, as well as Cd and Zn in the sediments, were particularly pronounced. Fish liver and gills contained higher concentrations of heavy metals than muscle. Furthermore, the concentration of essential metals (Cu, Zn, and Ni) in fish was greater than that of non-essential metals (Cr, As, Cd, and Pb). Among various fish species, A. nobilis demonstrated the highest capacity for heavy metal accumulation. PCA findings indicated that the primary contributors to heavy metal contamination in water were agricultural runoff and transportation activities. The health risk assessment revealed that both the Target Hazard Quotient (THQ) for individual micronutrients and the Hazard Index (HI) for multiple micronutrients were below one. In the cohort of children, the risk values (TR) for Cr in A. nobilis exceeded the threshold of 1×10−4. This research establishes a theoretical basis for advancing sustainable aquaculture in northern Anhui Province and promotes environmentally friendly practices.