Radiological safety assessment of chestnut (Castanea sativa) from Sinop province, Türkiye: Gamma spectrometric determination of natural radionuclides and associated health risks

Abstract

Naturally occurring radionuclides in foodstuffs are an important pathway for internal radiation exposure in humans. This study quantifies primordial radionuclides (238U, 232Th, 40K) in chestnut (Castanea sativa) from Sinop Province, Türkiye, and evaluates the associated radiological health risks from dietary intake. Thirty composite chestnut samples were analyzed using high-purity germanium (HPGe) gamma-ray spectrometry. Mean activity concentrations were 2.19 ± 0.20 Bq kg−1 for 238U, 2.60 ± 0.30 Bq kg−1 for 232Th, and 42.6 ± 1.5 Bq kg−1 for 40K, while 137Cs was below the minimum detectable activity in all samples. Using the national per capita chestnut consumption rate (0.7 kg y−1), the average total radionuclide intake was 90.94 ± 3.01 mBq day−1. The corresponding annual effective ingestion dose ranged from 0.84 ± 0.05 μSv y−1 to 3.68 ± 0.29 μSv y−1, and the excess lifetime cancer risk ranged from 12.85 ± 0.72 × 10−7 to 54.85 ± 2.06 × 10−7. These values are well below the public dose limit of 1 mSv y−1 recommended by the International Commission on Radiological Protection and below commonly accepted radiological risk thresholds. The absence of detectable 137Cs and the relatively low 238U, 232Th, and 40K levels indicate that chestnut consumption from Sinop does not pose an appreciable radiological health risk. The data also provides a food-based radiological baseline prior to operation of the planned nuclear power plant in the region. This baseline is relevant for future environmental radioactivity monitoring, food safety and regulatory control, and sustainable agricultural management in areas affected by current or prospective nuclear facilities.