Monte Carlo-based probabilistic assessment of natural radioactivity and radiological risk in infant formulas marketed in Turkey

Abstract This study provides the first comprehensive assessment of natural radionuclide contamination in commercial powdered infant formulas on the Turkish market. Twenty-four samples representing 12 major brands were analyzed using high-resolution gamma spectrometry to quantify the activity concentrations of 226 Ra, 232 Th, and 40 K. The measured mean activity concentrations were 1.51 Bq kg⁻ 1 for 226 Ra, 1.57 Bq kg⁻ 1 for 232 Th, and 239.9 Bq kg⁻ 1 for 40 K. The derived annual effective doses for infants under one year and those aged 1–2 years averaged 0.654 and 0.183 mSv y⁻ 1 , respectively, both below the 1 mSv y⁻ 1 safety threshold recommended by the ICRP and UNSCEAR. Monte Carlo simulations (10,000 iterations) showed the 95th percentile of excess lifetime radiological risk (ELRR) to be two orders of magnitude lower than the acceptable risk interval (10⁻⁶–10⁻ 4 ), indicating a very low radiological health impact within the framework of international radiological protection criteria. Principal component analysis identified two dominant components: a radionuclide factor driven by 226 Ra and 232 Th and a 40 K-associated nutritional factor. Despite the relatively elevated 226 Ra and 232 Th levels compared to the reference values, the overall radiological exposure from Turkish infant formulas remains within safe limits. These findings establish the first radiological baseline for Turkish infant formulas and emphasize the need for routine monitoring and standardized analytical protocols to ensure continued consumer safety. Graphical abstract