Justification of new safety standards in occupational exposure based on investigation of health risks among Chernobyl clean-up workers

Work number - P 14 FILED

Submitted by State Institution “The National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine”

Authors: Chumak V.V., Worgul B.V., Dyagil I.S., Vitte P.M., Skaletsky Y.N., Bakhanova E.V., Gudzenko N.A., Romanenko A.E.

The purpose of the series of studies was to obtain new knowledge about adverse effects of ionizing radiation on human health, specifically – to assess the risks of radiation-related leukemia and cataracts in exposed workers.

The authors had developed expertise in methods required to conduct such research - dosimetric (the "dose" axis of "dose-effect" dependence), diagnostic (the "effects" axis) and risk analysis of late effects of radiation ("dose-effect" relationship). They used these methods to gather new data regarding the cataract and leukemia risks in two large cohorts of Chernobyl liquidators. The study results provided substantiation of new international safety standards (dose limits) for occupational exposure to ionizing radiation.

State-of-the-art study protocols were developed together with international collaborators and applied in large-scale epidemiological cohort and case-control studies.

These included the first study worldwide in which  a convincing risk of radiation cataracts was found at a much lower threshold than previously known, as well as a study in which  chronic lymphocytic leukemia was shown to be radiation induced, while previously it had been considered to be insensitive to ionizing radiation.

This new knowledge gained international recognition: the findings were taken into account by UNSCEAR and ICRP and resulted in revision of the international radiation safety standards by IAEA and EURATOM – specifically, a significant (7.5 times) reduction of the dose limit for occupational exposure to the lens of the eye. The leukemia risks observed among the Chernobyl liquidators confirmed the validity of the existing limits on whole body radiation exposure.

Total number of publications related to the study: 264, including 6 monographs and 103 papers (including 53 in international journals). According to the Scopus database (in parentheses – according to Google Scholar database), the total number of citations of the publications included in this series is 1353 (2003), the maximum citation of one publication is 154 (225), h-index (of the series) is 20 (25). One patent is granted. Within the course of the work, 4 D.Sc. and 2 Ph.D. degrees were awarded.