Selenium Biofortification: A Dual-Edged Sword of Nutrition and Contamination Risk

Selenium is an indispensable trace element for the vital activities of humans and animals and plays a significant role in immunity, anticancer, and anti-oxidation. Selenium is closely related to soil, plants, animals, and human beings in nature, and the selenium content of soil and crops is important in assessing the selenium nutritional status of the population. The human body cannot synthesize selenium and needs to ingest it from food. However, selenium-rich agro-food may be accompanied by the risk of heavy metal (e.g., cadmium, lead, mercury, arsenic, and chromium) contamination while enhancing the selenium nutritional level of the human body, which poses a potential threat to the ecosystem and human health. Accordingly, this article advocates for a thorough risk assessment of selenium-enriched agricultural products that balances selenium's health benefits against potential heavy-metal contamination, adopts a whole agri-food-chain perspective (encompassing soils, crops, animal products, and human consumption), clarifies the interconnected transfer of selenium and heavy metals, and proposes a risk-management strategy focused on traceability systems and precision agriculture to safeguard the quality and safety of these products.