Technogenic contamination of livestock- and fish-derived food products with heavy metals and radionuclides in industrial and post-nuclear regions of Kazakhstan.

Background and Aim: Technogenic pollution from industrial activities and legacy nuclear testing remains a major environmental concern in several regions of Kazakhstan. Contaminants such as heavy metals and radionuclides can migrate through environmental matrixes into the food chain, potentially compromising the safety of livestock- and fish-derived food products. This study aimed to assess contamination levels of toxic elements and radionuclides in meat, poultry, milk, dairy products, and freshwater fish from technogenically hazardous regions of Eastern, Northern, and Central Kazakhstan and to evaluate their compliance with established safety standards. Materials and Methods: A cross-sectional monitoring study was conducted from August 2024 to September 2025 in the Abai, Akmola, and Karaganda regions. A total of 383 samples of meat, milk, and dairy products and 143 freshwater fish samples were collected from farms, retail markets, and local water bodies. Concentrations of lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) were determined using inductively coupled plasma optical emission spectrometry. Radionuclides cesium-137 and strontium-90 were analyzed using a multichannel gamma spectrometer with radiochemical methods where applicable. Descriptive statistics and analysis of variance were performed using IBM SPSS Statistics version 25, with p < 0.05 considered statistically significant. Results: Elevated concentrations of toxic elements were detected in several livestock products. The Karaganda region showed the highest contamination, including exceedances of Pb, Cd, Cu, and Zn in horse meat and elevated Cu in beef. In the Akmola region, exceedances were mainly observed for Cu and occasionally Cd, whereas in the Abai region Cd exceedances predominated. Poultry meat generally met safety standards, except for Cd exceedance in chicken from the Akmola region. In dairy products, Cd and Cu exceeded permissible levels in cottage cheese and milk in selected districts, while Pb exceeded limits in whole milk samples from the Abai region. Freshwater fish contained detectable heavy metals, but concentrations remained below maximum permissible limits. Radionuclide levels in all tested products were substantially below regulatory thresholds, and no statistically significant regional differences were observed. Conclusion: The findings demonstrate localized accumulation of toxic elements in livestock-derived foods in industrially impacted regions of Kazakhstan, while radionuclide contamination remains within safe limits. Continuous environmental monitoring and strengthened food safety surveillance are required to minimize health risks and ensure the safety of animal-derived food products in technogenically affected areas.