Determination of radium, thorium and potassium levels in some foods consumed in Kastamonu by gamma-ray spectrometric method

Adequate consumption of vegetables and fruits plays a very important role in attaining and keeping good health. Consuming vegetables and fruits that contain high levels of natural radionuclides can cause some health problems. In this study, the activity levels of radium (226Ra), thorium (232Th) and potassium (40K) radionuclide in some vegetable and fruit samples, which are frequently consumed in Kastamonu city center and collected from market places, were determined using gamma-ray spectrometric method. The activity concentrations of 226Ra, 232Th and 40K in twenty-eight vegetables and seven fruits samples varied 0.8 ± 0.1 to 32.8 ± 1.3, 0.7 ± 0.1 to 41.3 ± 21 and 391.8 ± 18.3 to 4679.0 ± 311.4 Bq/kg (dry weight) and 1.3 ± 0.1 to 12.6 ± 0.4, 1.4 ± 0.1 to 15.0 ± 0.5 and 133.0 ± 84 to 777.0 ± 69.4 Bq/kg (dry weight), The highest activity concentration of 226Ra and 232Th was measured in the garlic sample, while the highest activity concentration of 40K was measured in the spinach sample. The results obtained were compared with the results of similar studies in the literature. The average annual effective radiation dose that an adult can receive due to the internal irradiation caused by the ingestion of the studied vegetable and fruit samples and lifetime risk of cancer risk associated with the average annual effective dose was found as 201 µSv and 8.9 x 10-5, respectively. The contribution of 40K to the total annual effective radiation dose was calculated as approximately 70%. KEYWORDS: Vegetables, fruits, natural radioactivity, radium, thorium, potassium annual effective dose, Kastamonu