Minimum detectable annual dose calculation for routine individual monitoring programme in case of plutonium and uranium contamination of the workplace.

An example of a numerical method application for minimum detectable annual dose calculation that can be guaranteed by the operating monitoring programmes for plutonium and uranium is presented. The method analyses the frequency distribution for a total number of counts obtained in n measurements performed during n monitoring intervals that are inside the calendar year. Urine sample radiometric measurement technique for plutonium and uranium operating monitoring programmes is investigated, showing dependences of the detection limits on the frequency of measurements, on number of calendar years under observation and on the activity median aerodynamic diameter (AMAD). Only a probability density function (PDF), for the background number of counts, stochastic variability of urine excretion and uncertainty of the intake pattern were taken into account as the main variables influencing the calculated detection limits. But there is no limitation for the proposed method to include the variability of other influencing model parameters in the calculation procedure.

[Comparative investigation of structural and gene somatic mutations in workers of nuclear chemical plants. I. A study of stable and unstable chromosome aberrations].

A study of frequency of unstable chromosome aberrations in 50 workers of nuclear chemical plants in remote period after beginning or finishing professional contact with ionizing radiation was carried out. 14 persons from this cohort were mainly whole-body exposed to external gamma-rays and 36 were exposed to combined external and internal radiation from incorporated Pu nuclides. In results of this irradiating practically every subject had a chronical radiation sickness. In the 1-st group the frequency of unstable aberrations varied from 0.2 to 3.6 per 100 cells and exceeded reliably control level in 5 persons. In the 2-nd group the frequency of unstable aberrations varied from 0 to 11.6 per 100 cells and exceeded reliably control level in 20 examined workers. The FISH study of frequency of stable aberrations was performed in 13 subjects who were exposed to combined external and internal radiation. Total frequency of complete and incomplete translocations varied from 0.6 to 18.5 aberrations per genome per 100 cells and reliable exceeded control level in 9 subjects. Non-random participation in exchange rearrangements (translocations) was revealed for used set of chromosomes (2, 3 and 8).

[Comparative investigation of structural and gene somatic mutations in workers of nuclear chemical plants. II. Frequency of lymphocytes mutant in T-cell receptor loci].

Frequency of lymphocytes mutant at T-cell receptor (TCR) loci was defined in 42 workers of nuclear chemical plants. In 11 persons mainly exposed to external radiation the mean frequency of TCR-mutant lymphocytes was statistically significant by higher compared with control group of unexposed donors: 9.1 x 10(-4) vs 3.5 x 10(-4) correspondently (p < 0.01). Frequency of TCR-mutant lymphocytes did not correlate neither the frequency of structural mutations non doses of external exposure. In group of workers exposed to combined external and internal radiation (n = 31) the average frequency of TCR-mutant lymphocytes was higher compared with control level: 8.9 x 10(-4) vs 3.5 x 10(-4) correspondently (p < 0.01). Correlations between the frequency of TCR-mutant cells and Pu content in organism (r = 0.5; p = 0.005) and between the frequency of chromosome aberration of unstable and stable types (r = 0.5; p = 0.002 and r = 0.6; p = 0.036, correspondently) were set. Comparison of results of analysis of structural and gene mutations allows us to supose that in case of external exposure the observed disturbances can result from genome instability in remote period after irradiation. In case of combined exposure the genetic changes were possibly caused by the constant action of alpha-radiation from Pu containing in the body.

[Hemopoietic response to americium and plutonium exposure in nuclear industry workers]. / Reaktsii krovetvornoi sistemy u rabotnikov atomnoi promyshlennosti pri vozdeistvii ameritsiia i plutoniia.

The examinees demonstrated definite effects caused by total influence of Am-241 and Pu-239: chronic radiation sickness with diffuse pneumosclerosis, chronic toxic radiation bronchitis and peripheral blood changes (reactive alterations and stable lower platelets and reticulocytes count), microfocal hypoplasia, osteodysplasia, reactive hepatopathy. Frequency of these effects increased with higher radiation exposure and did not depend on the age.

[Establishing of doses from the internal irradiation for the personnel of the Chernobyl AES and persons detailed in 1986-1987]. / Formirovanie doz ot vnutrennego oblucheniia dlia personala Chernobyl'skoi AES i komandirovannykh v 1986-1987 gg.

The paper is concerned with the results of measurements of characteristics of the air media in the zone of the damaged reactor as with the assessment of doses from internal irradiation on the basis of calculations of air media parameters and the results of actual measurements of the uptake and content of radionuclides in the personnel of the Chernobyl Nuclear Power Station and persons sent on mission there in 1986-1987, the results being obtained by indirect and direct biophysical methods of control of internal irradiation. The calculated data are well in accord with the results of actual measurements of the contents of radionuclides in the body. Internal irradiation of all tissues and organs, determined by the inhalation of a mixture of radionuclides, worked almost completely within the first year following the accident, the thyroid being the critical organ. In the next years internal irradiation for the personnel of the Chernobyl Nuclear Power Station was determined entirely by transuranic elements and was about 0.1 M.P.D annually for bone tissue. The value of a mean effective equivalent dose from internal irradiation in 50 years is 85 mSv for professionals, and a contribution of internal irradiation to the whole-body one over the first well as is 13%.

[Modifying effect of the chemical components of dust on the induction of lung tumors by physical and chemical carcinogens (experimental study]. / O modifitsiruiushchem vliianii khimicheskikh komponentov pyli na induktsiiu opukholei legkogo fizicheskim i khimicheskim kantserogenom (éksperimenta'lnoe issledovanie).

Chronic inhalation intake of benzo(a)pyrene (BP) and polonium-210 (210Po) together with aluminum oxide caused increase of tumor formation in the lungs of mice. Synergy of BP and 210Po carcinogenic effect was pointed out, it was characterized by summation and possible effect involution by tumor development rates and the duration of the latent period. BP and 210Po carcinogenic effectiveness depended on the type of dust carrier and probably on the presence of silicon dioxide and also carcinogenic metals. It was pointed out that further studies were necessary to determine an etiologic role of mineral dust chemical components in carcinogenic activity of the above substances and also carcinogenic effectiveness of dusts as carriers of chemical carcinogens and alpha-active radionuclides.