Comparative evaluation of thyroid operational intervention levels depending on age and biokinetic model in nuclear accidents

Abstract

In order to minimize the risk of stochastic effects from thyroid exposure by radioiodine during a nuclear accident, it is essential to implement prompt and timely protective actions based on accurate assessments of thyroid dose. This study aims to evaluate the impact of age- and model-specific iodine biokinetic parameters on the thyroid Operational Intervention Level (OIL8ᵧ). A comparative analysis was conducted using biokinetic parameters for various age groups and iodine biokinetic models. The methodology involved calculating OIL8ᵧ functions based on these parameters and subsequently comparing the results through relative deviations. The results indicate that the OIL8ᵧ for the 1-year age group, characterized by faster iodine clearance, declines more rapidly than that of other age groups. Similarly, the OIL8ᵧ for the Korean model, which reflects higher dietary iodine consumption, also exhibited a more pronounced decrease compared to other biokinetic models. These results suggest that the current OIL8ᵧ may not fully represent specific populations. Consequently, it is recommended that adjustments to the OIL8ᵧ criteria should be made to more accurately reflect the unique biokinetic behaviors of infants and Koreans. Such targeted adjustments to the monitoring strategy may ensure the timely implementation of protective response actions for specific groups during nuclear accidents.