Impacts of water management in aquaculture on heavy metal accumulation in rainbow trout muscles and associated health risks from consumption

The research aimed to assess the impact of water management technologies in rainbow trout farms on the accumulation of heavy metals in fish muscles. Additionally, the health risks associated with their consumption were evaluated. In the context of increasing demand for fish products, the study compares recirculating aquaculture systems (RAS) with flow-through systems (FTS), presenting a novel approach to assessing the impact of fish production in aquaculture on the quality of their meat. This study is innovative, as it integrates environmental data analysis of water quality and feed composition with measurements of metal accumulation, providing a comprehensive picture of how different water management technologies in aquaculture affect food safety related to fish meat consumption. The research was carried out in six Polish farms, allowing for a detailed comparison of both water management systems. Advanced analytical techniques, including ICP-OES and statistical analyses, were employed to analyze the chemical composition of fish meat, water, and feed. To evaluate the impact of consuming trout meat on human health, measurements such as Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Hazard Index (HI), Cancer Risk Factor (CRF), and Cancer Hazard Index (CHI) were calculated. The results indicated that the content of heavy metals in the tested trout muscle samples was low and did not exceed the highest permissible levels defined in EU Regulation 2023/915. However, the health risk, measured by EDI and HI indicators, was slightly higher in RAS systems, although HI values below 1 indicate minimal risk. It was found that the type of water management technology in trout production (FTS vs. RAS) influences the level of bioaccumulation of heavy metals in the meat. Trout from RAS systems had a higher level of bioaccumulation of the heavy metals studied compared to FTS systems. Although the differences in heavy metal levels between the two systems were relatively small, they suggest optimizing water management in RAS systems could reduce bioaccumulation levels. The study highlights the importance of optimizing farm water management to protect consumer health. These results have significant implications for aquaculture practices, indicating the need for monitoring and optimizing water management to minimize consumer health risks.