Evaluation of endocrine changes in liquidators: the early and late post-accident period

Abstract

The purpose of this study was to identify and assess endocrine disorders in liquidators (emergency workers) of the Chernobyl NPP accident, depending on the radiation and non-radiation factors in the early and late post-accident periods using the methods of system analysis. On the basis of long-term research we found that there is a gradual decrease in thyroxine, triiodothyronine and thyrotropin levels. The resulting regression formulas enable to predict further decrease of these parameters at least for the next 3-5 years. Variance factor analysis allowed revealing that in the first years after the accident radiation factor mainly affected the change of these indicators, but in more than 25 years, the share of the age factor has become more important in the overall impacts. In the group of liquidators and the control group in 1987 and 5 years after the Chernobyl accident revealed that although the average concentration of cortisol in the study groups was in the normal range, at an early post-accident period there was observed a tendency to increase in liquidators and the concentration value was significantly different from the control. The value of adrenocorticotropic hormone in the early post-accident period differed significantly from the norm, and by the late period the difference between the values of adrenocorticotropic hormone and cortisol in liquidators and the control group became insignificant. In the long-term a trend toward normalization takes place, but some understated level of indicators can be explained plainly by transition to the other age group.