Neurological syndromes from occupational chronic radiation exposure (the early effects)

The nervous system for individuals occupationally exposed to chronic ionizing radiation is evaluated. The nervous system data were studied retrospectively for 1090 workers of the first Russian nuclear enterprise MAYAK. The study had an advantage in availability of individual dosimetry data and complete primary medical records. The complex nervous system evaluation implied assessment of initial health data at the started work with ionizing radiation sources and for the following 40-50 years of observation at a specialized medical institution. Vegetative-vascular dysfunction (VVD) of hypotensive type (51.8%), hyposthenia (35.2%) and micro-organic changes in the central nervous system (9.3%) were more frequently registered for workers during the period of maximum radiation exposures. A direct dependence of the incidence of mentioned neurological syndromes on annual and total doses due to external γ-rays was revealed both for males and females. The frequency of neurological syndrome combination increased from 10.0% to 92.4% with the increased annual dose due to external γ-rays from 0.5 to 7.0 Gy/ year.