Long-Term Hemopoiesis and Immunity Status after Chronic Radiation Exposure of Red Bone Marrow in Humans

Alexander V. Akleyev, Galina A. Veremeyeva, Larisa A. Silkina and Alexander V. Vozilova

Urals Research Center for Radiation Medicine, Chelyabinsk, Russia1
 
Corresponding author: Alexander V. Akleyev, M.D.
Urals Research Center for Radiation Medicine
Medgorodok, Chelyabinsk, 454076, Russia
Tel.: (+351) 2 344 762; Fax: (+351) 2 344 321
e-mail:akleyev@urcrm.chel.su


CEJOEM 1999 5(2):113-129


ABSTRACT: The focus of the paper is on the results of clinical observations and laboratory investigations performed for individuals exposed to chronic radiation due to discharges of about 3 million Ci of radioactive waste from the Mayak Industrial Association into the river Techa in 1949–1956. The population of the riverside villages was exposed to a combined external gamma- and internal (mainly due to Sr-90) radiation. Given the nature of the exposure, the red bone marrow (RBM) was a critical organ for the exposed residents. During the first 2–4 years after the onset of chronic exposure, changes observed in the peripheral blood were manifested by leukopenia (mostly due to reduced neutrophil counts), thrombocytopenia and inhibition of non-specific immunity factors, at equivalent dose rates to RBM of 300–500 mSv per year, and higher. In the 1950s 940 residents with highest exposure doses were diagnosed with chronic radiation sickness. At late times (43–48 years after the beginning of exposure) the status of hemopoiesis and immunity is normal among most of the exposed subjects. However, proportions of the exposed persons are still noted to show an increased frequency of chromosomal aberrations (both stable and unstable types) and CD3 – CD4+ mutant T-lymphocytes in the peripheral blood.

KEY WORDS: Red bone marrow, hemopoiesis, immunity, chronic radiation exposure, chronic radiation sickness, chromosome aberrations, translocations, somatic mutations, T-cell receptor


Acknowledgments
The authors would like to convey their deep gratitude to Dr. A. Awa, Dr. S. Kyoizumi (RERF), Prof. M. Bauchinger (GSF) for their assistance in conducting research of somatic mutations and stable chromosome aberrations, and to Dr. E. Tolstykh for her help in dose calculation.

Received: 23 June 1999
Accepted: 29 July 1999

Posted: December 1999

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