An effective dose assessment technique with NORM added consumer products using skin-point source on computational human phantom

The aim of this study is to develop the assessment technique of the effective dose by calculating the organ equivalent dose with a Monte Carlo (MC) simulation and a computational human phantom for the naturally occurring radioactive material (NORM) added consumer products. In this study, we suggests the method determining the MC source term based on the skin-point source enabling the convenient and conservative modeling of the various type of the products. To validate the skin-point source method, the organ equivalent doses were compared with that by the product modeling source of the realistic shape for the pillow, waist supporter, sleeping mattress etc. Our results show that according to the source location, the organ equivalent doses were observed as the similar tendency for both source determining methods, however, it was observed that the annual effective dose with the skin-point source was conservative than that with the modeling source with the maximum 3.3 times higher dose. With the assumption of the gamma energy of 1 MeV and product activity of 1 Bq g⁻¹, the annual effective doses of the pillow, waist supporter and sleeping mattress with skin-point source was 3.09E-16 Sv Bq⁻¹ year⁻¹, 1.45E-15 Sv Bq⁻¹ year⁻¹, and 2,82E-16 Sv Bq⁻¹ year⁻¹, respectively, while the product modeling source showed 9.22E-17 Sv Bq⁻¹ year⁻¹, 9.29E-16 Sv Bq⁻¹ year⁻¹, and 8.83E-17 Sv Bq⁻¹ year⁻¹, respectively. In conclusion, it was demonstrated in this study that the skin-point source method could be employed to efficiently evaluate the annual effective dose due to the usage of the NORM added consumer products.