Activity concentrations of U, Th, Ra Cs and K radionuclides in honey samples from Romania. Lifetime cancer risk estimated.

Romania is on the first place in Europe with an annual production of honey of 30.9 thousand tons in 2018, while the European Union is on the second place in the world with a total of 283 thousand tons. The most part of the honey production from Romania is exported. The aim of this study was to estimate internal radiation doses and lifetime cancer risk from honey ingestion sampled from several locations on the Romanian territory. The activity concentration of Cs and U is found to be below the detection limit of the method. The activity of Ra ranged from lower than the minimum detectable value (<1.08 Bq·kg) to 7.35 ± 1.73 Bq·kg. For Th and K the average recorded values were 1.51 ± 0.74 and 24.08 ± 4.37 Bq·kg, respectively. The annual effective dose due to the intake of Th, Ra, K has been assessed ranging from 0.08 to 0.47 (μSv·y), 0.35 to 1.65 (μSv·y) and 0.04 to 0.33 (μSv·y), respectively. Ra gives the largest contribution (56-82%) to the total annual effective dose due to ingestion received by consumption of honey, in the samples where it was identified. In the other samples (where Ra was below the detection limit), the largest contribution to annual effective dose is due to Th (45-85%). The values obtained from the lifetime cancer risk calculation range in the domain from 2.85·10 to 1.78·10 for Th, 1.33·10 to 6.22·10 for Ra and 1.38·10 to 1.25·10 for K. For Cs, only one value was recorded 2.20·10. The Th, Ra, K and Cs activities measured in the present work were comparable with completion of others activated values of honey samples around Europe.