Activity concentrations of 238U, 232Th, 226Ra 137Cs and 40K radionuclides in honey samples from Romania. Lifetime cancer risk estimated

Abstract

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 137Cs and 238U is found to be below the detection limit of the method. The activity of 226Ra ranged from lower than the minimum detectable value (<1.08 Bq·kg−1) to 7.35 ± 1.73 Bq·kg−1. For 232Th and 40K the average recorded values were 1.51 ± 0.74 and 24.08 ± 4.37 Bq·kg−1, respectively.The annual effective dose due to the intake of 232Th, 226Ra, 40K has been assessed ranging from 0.08 to 0.47 (μSv·y−1), 0.35 to 1.65 (μSv·y−1) and 0.04 to 0.33 (μSv·y−1), respectively. 26Ra 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 226Ra was below the detection limit), the largest contribution to annual effective dose is due to 232Th (45–85%).The values obtained from the lifetime cancer risk calculation range in the domain from 2.85·10−7 to 1.78·10−6 for 232Th, 1.33·10−6 to 6.22·10−6 for 226Ra and 1.38·10−7 to 1.25·10−6 for 40K. For 137Cs, only one value was recorded 2.20·10−8.The 232Th, 226Ra, 40K and 137Cs activities measured in the present work were comparable with completion of others activated values of honey samples around Europe.