Rahman Md Hamidur, Alshaya Dalal Sulaiman, Ramadan Haitham, A Attia Kotb, Sultana Nadira, Rohani Md Fazle, Wijaya Anugrah Ricky, Hossain Md Sazzad
Department of Aquaculture, Bangladesh Agricultural University, Mymensingh, Bangladesh.
Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.
Vet Med Sci. 2025 Sep;11(5):e70562. doi: 10.1002/vms3.70562.
The levels of five heavy metals-zinc (Zn), lead (Pb), chromium (Cr), cadmium (Cd) and arsenic (As)-in soil, water, feed and fish were investigated in this study at different culture phases (early, nursery, grower and harvest) of Oreochromis niloticus (tilapia). Unlike previous studies that focused on one or two sources, this research provides a comprehensive assessment across all major inputs during the entire production cycle, offering new insight into potential contamination pathways.
Heavy metal accumulation varied across sources and stages. Cr and As in sediment, and Cr in feed at the early stage, exceeded the permissible boundaries set by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). As the culture progressed, sediment showed increasing levels of Pb, Cr and As, all surpassing safe thresholds during the nursery to harvest phases. Feed also retained elevated Cr concentrations throughout. In contrast, water samples showed minimal contamination, and heavy metal levels in fish stayed within acceptable bounds for human consumption, although Zn and Cr gradually increased toward harvest. These findings suggest that sediment and feed are the primary sources of heavy metal accumulation, with water contributing minimally.
The results indicate that tilapia raised in contaminated environments may not pose an immediate risk to consumers, but long-term exposure through sediment and feed can lead to gradual metal build-up. Therefore, routine monitoring of feed quality and sediment conditions is critical for safe aquaculture practices. These findings offer valuable guidance for hatchery operators and fish farmers, emphasising the need for preventive strategies to ensure the sustainable and safe production of tilapia.
本研究调查了尼罗罗非鱼（罗非鱼）在不同养殖阶段（早期、育苗期、养成期和收获期）土壤、水、饲料和鱼体中锌（Zn）、铅（Pb）、铬（Cr）、镉（Cd）和砷（As）这五种重金属的含量。与以往专注于一两个来源的研究不同，本研究对整个生产周期内所有主要投入物进行了全面评估，为潜在污染途径提供了新的见解。
重金属积累在不同来源和阶段有所不同。沉积物中的铬和砷，以及早期饲料中的铬，超过了联合国粮食及农业组织（粮农组织）和世界卫生组织（世卫组织）设定的允许界限。随着养殖进程推进，沉积物中铅、铬和砷的含量不断增加，在育苗期至收获期均超过了安全阈值。饲料中的铬含量在整个过程中也一直居高不下。相比之下，水样污染程度最低，鱼体中的重金属含量在人类食用可接受范围内，不过锌和铬在收获期逐渐增加。这些发现表明，沉积物和饲料是重金属积累的主要来源，水的贡献最小。
结果表明，在受污染环境中养殖的罗非鱼可能不会立即对消费者构成风险，但通过沉积物和饲料的长期接触会导致金属逐渐积累。因此，对饲料质量和沉积物状况进行常规监测对于安全的水产养殖实践至关重要。这些发现为孵化场经营者和养鱼户提供了有价值的指导，强调了采取预防策略以确保罗非鱼可持续安全生产的必要性。
