[Assurance of safety and personal protection of the personnel working in conditions of external radiation exposure].

The article contains detailed analysis of current scientific approaches and practical achievements in organizing personal protection of the personnel working in conditions of external radiation exposure and air and surface contamination with radioactive substances. The ways of improvement of personal protection equipment are described. The incorrectness of attempts to create PPE from gamma radiation with the energy of over 0,1 MeV--which are currently quite common--is shown.

[Reply to the letter-to-the-editors by V.A. Pitkevich, V.K. Ivanov, S.Iu. Chekin, A.F. Tsyb, "Concerning the problem of radiation exposure levels to the Chernobyl AES accident clean-up participants, included in Russian Medical-Dosimetric State Registry"].

Theoretical and practical problems related to the dosimetric data verification for recovery workers at the Chernobyl NPP are considered. The distinctions in definitions epsilon-entropy in paper [1] and delta-entropy in [2] are considered. In a certain measure this distinctions explain distinction in conclusions, made in these papers.

[New standards for radiation safety and effective dose].

The scientific bases and the peculiarities of the new radiation safety standards (RSS) implemented in Russia in april 1996 are considered. A comparison is made of the merits and shortcomings of both conceptions of standardization--by means of setting dose limits for the critical organs or by means of limiting the effective dose as a measure of the total radiation risk of late effects. The application of the effective dose to practice gives unquestionable advantages for assessing the sufficiency of arrangements providing radiation safety of personnel or public protection against radiation.

[The need to account for beta radiation in determining the total radiation exposure of those working in cleanup].

The role of external beta-radiation as one of the major radiation factors effected persons involved in recovery operations (liquidators) after the accident at the Chernobyl nuclear power plant is considered. The paper uses the data of discriminate individual dosimetric monitoring of beta- and gamma-radiation for different groups of liquidators and experimentally received dose distribution in tissue equivalent material in the places of carrying out work. The results obtained by calculation were also used.

[The irradiation levels of the participants in the cleanup of the aftermath of the Chernobyl accident in 1986-1987 and the verification of the dosimetric data].

It is considered the organization of individual dosimetric monitoring (IDM) within 30-km zone around Chernobyl nuclear power plant (CNPP) in 1986 for different contingents of recovery workers: the CNPP personnel, Management for Construction 605 (MC-605), military recovery workers, persons assigned to 30-km zone. It is concluded that the quality of IDM had decreased in the following series: the MC-605 personnel, the CNPP personnel, the assigned persons, and military units. The method of dosimetric data verification for recovery workers in 1986 is presented which is based on the analyses of the dependency H(delta)/In delta from delta, where delta is a step of the histogram of distribution, and H(delta) is delta-entropy of distribution.

The dependence of skin lesions on the depth-dose distribution from beta-irradiation of people in the Chernobyl nuclear power plant accident.

A detailed study was made of the conditions of exposure of 56 victims of the Chernobyl accident who suffered radiation lesions in the skin. The most typical conditions were experimentally reconstructed in order to investigate the specific characteristics of the distribution of doses to the skin according to depth for different exposure conditions. The absorbed doses at depths of 7 mg cm-2 and 150 mg cm-2 were calculated on the basis of measurements with multilayer skin dosemeters.

[Role of injuries to the vascular plexus in the development of a radiation lesion of the skin in swine].

A single action of beta-radiation of different energy on the swine skin was studied. The analysis and comparison of clinical and histological features of radiation injury to the mode of the absorbed dose formation associated with the depth of location of the skin structural elements permitted to consider deep vascular plexus of the dermis to be the second critical structure (in addition to basal layer of the epidermis) responsible for the radiation reaction development and for the rate and completeness of repair processes, in particular.

[The effect of the size of the irradiation field on the severity and outcome of the radiation injury of swine skin].

Swine skin areas of 12.56 cm2, 50 cm2 and 100 cm2 were exposed to beta-particles from 90Sr + 90Y (100 Gy). The increase in size of the exposed site caused a considerable increase in the degree of the affection and a change in the regeneration rate.