Assessment of radioactivity levels and radiological health risks of commercial medicinal and aromatic herbs consumed in Türkiye

The raw parts (roots, leaves, seeds, flowers, etc.) and extracts of medicinal and aromatic herb (MAH) species are widely utilized in traditional and modern medicine as drugs to treat disease and/or prevent illnesses. MAH species absorb nutrients and minerals from the soil, as well as toxic elements and radionuclides dispersed in the environment. Thus, this may provoke concerns about the possibility of human internal exposure to radionuclides found in these MAH species. This study aims to create a detailed database related to the activity concentrations of the natural (²²⁸Ra, ²²⁶Ra, and ⁴⁰K) and artificial (¹³⁷Cs) radionuclides in popular commercial MAH species consumed in Türkiye and potential radiological health risks (PRHRs) due to the ingestion of MAHs. The activity concentrations (Bq/kg) of the radionuclides analyzed in the commercial popular 98 MAH samples by a gamma-ray spectrometric method varied from <0.6 to 19.3 with an average of 6.9 (²²⁸Ra), <0.5 to 37.5 with an average of 8.6 (²²⁶Ra), and 32 to 1297 with an average of 358 (⁴⁰K). All activity concentrations of ¹³⁷Cs were found below 0.3 Bq/kg. The average values of total annual effective dose, mortality cancer risk, and morbidity cancer risk estimated for adult consumers to assess PRHRs were found to be 16.5 μSv/y, 6.0 × 10^-5 and 8.9 × 10^-5, respectively. This study reveals that radiological data are below acceptable limits for public health, and therefore, the studied MAH samples are safe in terms of radiological risk.