The feasibility of using I-129 to reconstruct I-131 deposition from the Chernobyl reactor accident

Radioiodine released to the atmosphere from the accident at the Chernobyl nuclear power station in the spring of 1986 resulted in large-scale thyroid-gland exposure of populations in Ukraine, Belarus, and Russia, Because of the short half life of I-131 (8.04 d), adequate data on the intensities and patterns of iodine deposition were not collected, especially in the regions where the incidence of childhood-thyroid cancer is now increasing, Results are presented from a feasibility study that show that accelerator-mass-spectrometry measurements of I-129 (half life 16x10(6) y) in soil can be used to reconstruct I-131-deposition density and thus help in the thyroid-dosimetry effort that is now urgently needed to support epidemiologic studies of childhood-thyroid cancer in the affected regions.