Radionuclides in the food chain: focus on animal-derived food

The paper presents an analytical overview of the occurrence, movement, and accumulation of both natural and anthropogenic radionuclides in food of animal origin. The research encompasses the main pathways through which these substances enter animal organisms, together with the environmental and agricultural factors influencing their distribution in soil, vegetation, and animal tissues such as meat, milk, eggs, and fish during the period 1989 to 2025. The review was conducted based on a literature search performed in the Elsevier, Hinari, PubMed, and other relevant scientific databases. The study focuses on isotopes including uranium-238, thorium-232, potassium-40, cesium-137, and strontium-90 as key indicators of naturally occurring and technologically induced radioactivity within the biosphere. The analysis demonstrates the interconnection between geological, climatic, and agricultural conditions that determine the levels and variability of radionuclides in animal-derived food. It was established that radionuclide concentrations in North Macedonia fall within internationally accepted limits and correspond with values observed in other European countries. The study emphasizes the importance of continuous monitoring of both natural and anthropogenic sources of radioactivity to enable timely detection of fluctuations in radiological balance and to ensure the long-term safety of food and public health protection.