Medical Radiology and Radiation Safety. 2013. Vol. 58. No. 3. P. 24–33

RADIATION MEDICINE

N.G. Vlasova

Methodological Approach to Individualized Dose Reconstruction of People Exposed Due to the Accident at the Chernobyl NPP

The Republican Research & Practical Centre for Radiation Medicine & Human Ecology”, Health Ministry of the Republic of Belarus, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Purpose: To reveal the stability of relative internal dose in individuals and families of rural society and justify the use of this law for individualized dose reconstruction of people exposed in the result of the Chernobyl accident.

Materials and methods: The material of the study were the data on internal doses estimated according to the results of the WBC-measurements of cesium content in inhabitants of the Kirov settlement, Narovlya district, Gomel region, for the period between 1990 and 1999, been contained in “Database of the WBC-measurements in Belarusian residents for the period between 1987 and 2008”, registration certificate 5870900637 from 20.05.2009.

The following methods of applied statistics have been used: analysis of variance, multivariate statistical analysis. To confirm the assumption about the stability of relative internal dose, the rank test of concordance has been used. The credibility of differences has been estimated according to the Mann–Whitney criteria in order to compare the samples, which do not submit to normal distribution shape. Statistical processing of the materials has been carried out with the use of statistical software package STATISTICA 6.0 and MICROSOFT EXCEL 2010.

Results: The conducted analysis of the internal dose distribution in residents of the Kirov settlement for a 10-year period has confirmed the hypothesis that the dose of each individual and each family has its certain place on the dose distribution curve, which is constant in time, in other words, the individuals, families and its members have the same relative doses. High values of concordance coefficient (0.889 and 0.851) confirm the assumption about a relatively stable rank of relative internal doses of the examined individuals and families.

The spring-summer season: March, April, May, June, July, and autumn-winter season: August, September, October, November, December, January, February, had been shared out according to the method of one-way ANOVA. The average internal doses for these seasons significantly differed. The stability of relative internal dose for individual residents and families had been also revealed for two seasons.

Conclusion: The established law can be used as methodological basis for individual dose reconstruction at any time period of the accident. It is of great practical importance for assessment of the individual dose included in the Belarusian State Register of people exposed in the result of the Chernobyl accident.

Key words: individual, family, internal dose distribution, stability, year seasons