External radiation dose reconstruction for settlements near the Semipalatinsk nuclear test site, Kazakhstan, in the international multicenter study: a detailed review and comparative analysis of the initial data.

Studies on health effects of radiation exposure to residents around the Semipalatinsk nuclear test site (SNTS), Kazakhstan, are necessary for epidemiological assessment of radiation-related health risks after low-dose irradiation. Radiation dose estimates are the principal point for radiation epidemiological studies. These estimates should be based on the most reliable initial data, used for dose estimations. The comparative critical analysis of various available archival and published initial data, namely values of historical exposure dose rates and values of soil contamination by 137Cs in considered settlements, including information about dates, times and locations of measurements, was performed with the aim to select most reliable and realistic initial data necessary for estimation of settlement-average accumulated external doses for some settlements located in the vicinity of radioactive clouds' trajectories related to the most significant tests at the SNTS. Results of estimation of accumulated external radiation dose to air, based on these selected initial data, are presented for 18 settlements. Calculated accumulated external doses were compared with retrospective instrumental dose estimates for settlements, where data on TL/OSL luminescence retrospective dosimetry with quartz-containing samples or electron spin resonance (ESR) dosimetry with tooth enamel were available. Estimation of settlement-average external radiation dose to air is the first important step necessary for the next step-individualized radiation dose estimations among different age, professional and ethnic-specific groups of population lived in the study settlements considering behavior, shielding, location and relocation factors in each population group. This is a subject of future work.