Purpose: To study radiation and health physics situation in the vicinity of the shipyards “The 10th Shipyard, a Holder of Order of the Red Banner of Labor” (JSC “10 SRZ”) and “The Nerpa Shipyard” – a branch of the JSC “The Shipyard Center “Zvezdochka” (SRZ “Nerpa”) after the completion of the main stage of nuclear submarine dismantling and to assess potential effect of on-going activities to the environment and population. Material and methods: The following methods were used in radiation survey: pedestrian gamma survey of the site using portable gamma spectrometry complexes, gamma spectrometry and radiochemistry methods to determine the activity of manmade radionuclides in samples of environmental media. Results: Radiation and health physics studies were carried out from 2013 till 2017. It was shown that gamma dose rate within the health protection zones and supervision areas (SA) of the shipyards including the territories of the nearest cities – Snezhnogorsk and Polyarnyi – was at the level of regional values and did not exceed 0.14 µSv/h. The activities of radionuclides in soil from the surveyed sites did not exceed 23 Bq/kg for 90Sr and 100 Bq/kg for 137Cs. Concentrations of 90Sr and 137Cs in plants (mosses) at the surveyed sites did not exceed 70 and 48 Bq/kg, respectively, this is a bit higher than the background levels of the reference village of Belokamenka (1 and 20 Bq/kg, respectively, for 90Sr and 137Cs). The activity of seawater (Barents Sea) in 2016–2018 reached 60 mBq/l for 90Sr and 4 mBq/l for 137Cs, at mean values from 2 to 4 mBq/l over the period between 1990 and 2000 for the studied radionuclides. Data for 137Cs and 90Sr measured in samples of local wild plants, in particular, mushrooms, did not exceed 100 Bq/kg, this is much lower than the established permissible specific activities. Conclusion: Considerable impact of the work on the dismantling of nuclear submarines, maintenance ships and ships with a nuclear energy installation on the radiation situation in the areas of shipyards and health effects in the population of Snezhnogorsk and Polyarnyi was not revealed. However, along the external border of the surveyed shipyards some local parts of the sites of 5500 m2 area were found, where the specific activities of 90Sr and 137Cs in soil exceeded background levels and bordered by the level of permissible specific activity for unlimited use of solid materials (137Cs – 100 Bq/kg).

Purpose: To assess the reproductive health of male staff in the main departments of the Kursk nuclear power plant (NPP). Material and methods: The fertility and health of newborns were investigated. Data on marital status of 626 men of the staff and data about 813 newborns in families of male staff were analyzed. In the control group the data on the health status of newborns and pregnant groups of the population of Kurchatov city was used. Sources of information on doses to the personnel were the forms of a single system for monitoring and recording individual doses of radiation № 1-DOS “Information on the doses to persons in the conditions of normal operation of technogenic sources of ionizing radiation”. Results: Total occupational doses to the end of the main reproductive period (20–40 years) did not exceed 210 mSv, which is significantly below the threshold for temporary sterility during long-term irradiation (400 mSv/year, ICRP). Cases of infertile marriages in the families of the men of the staff (0.17 %) are below the estimation of the frequency of male infertility in Russia (1–2 %). Infant health in families of male staff and in the control group had no differences. The frequency of birth of health children was 65.3 % in families of male staff and 66.0 % for the control group. Frequency of birth of children with malformations was 35.7±6.5 per 1,000 live births and statistically (p = 0.84) did not differ from the frequency in the control group (37.4±5.3 per 1,000 live births) and was below the level adopted by the ICRP to calculate the radiation genetic risk (60 per 1,000 live births). There were no differences influenced by mother factors (age, diseases and complications during pregnancy) on fetal development and newborn health in families of the staff and control group. According to the calculations, the total occupational doses to men before the conception of children for more than 98 % of cases did not exceed 100 mSv, i.e. it was below the doses (>100 mSv), for which the genetic effects were observed in the number of epidemiological studies. However, it should be noted that 25.6 % of childbirth were in families, where men were older than 30 years, i.e. at the age, which is not subject to the additional job restrictions under the planned increased exposure. Conclusions: The impact of occupational exposure on the reproductive health status of men staff of the Kursk NPP was not identified.

Purpose: To assess the excess relative risk in terms of 1 Sv on the basis of materials on the incidence of malignant neoplasms of workers in the nuclear industry – liquidators of the Chernobyl accident, as well as part of workers who worked or continue to work with sources of ionizing radiation. Material and methods: The data base of the Industry Register of persons exposed to radiation as a result of the Chernobyl accident (ORF) was used in the work. Methods of cohort analysis of the accumulated disease incidence were used, based on Poisson regression and Cox regression. Estimates of the ERR at 1 Sv were calculated using both the traditional scheme using the AMFIT module and the modified formula proposed by Paretzke. Results: It is shown that in some cases, the risk estimates obtained by the modified formula are more realistic, in other cases both estimates have similar values. Conclusion: Analysis of the incidence of solid neoplasms in the liquidator cohort showed: 1. At the dose range < 200 mSv, point estimates of relative risk indicate that there is no dose-associated risk. 2. In the low-dose range for risk assessment, a modified Poisson regression approach that is free of control specifics should be used. 3. The validity of a dose response is characterized by the risks obtained using a dose of occupational exposure. 4. An important issue is the calculation of the risk of radiation-caused diseases with the use of the total dose received by an individual from all types of radiation.

Purpose: A synthetic study of published data on the growth and development of laboratory rats (albino random-bred, Wistar and Long–Evans) depending on the period of their breeding since 1906 was carried out. Material and methods: Data for the dynamics of growth and age periods of rats were used for calculations and general analysis. Results: Acceleration in terms of age–weight indices for strain animals was found: in conditions of complete diets ad libitum the contemporary rats grew several times faster than the bred ones of 1906–1932. For random-bred rats only the tendency to acceleration was obtained. For more than a century, the Wistar males showed an inverse linear correlation between the breeding year and the age (in weeks) at the of the onset of puberty period (according to the Spearman test: r = –0.952; p = 0.00026; Pearson’s criterion: r = –0.950, p = 0.0003). There was also a direct correlation between the body mass of rats at the time of puberty onset and the year of their breeding (according to the Spearman test: r = 0.975; p = 0.005; Pearson criterion: r = 0.927; p = 0.023). The possible reasons for the acceleration of laboratory growth of rats, which are unlikely to be analogous to the factors presumably causing the known ‘growth acceleration’ in humans (changes in natural and artificial lighting, the effect of heterosis, improvement of socio-hygienic conditions, the growth of information flow, warming of the climate, change in the geomagnetic or radiation background, etc.) were discussed. Apparently, in addition to the probability of special and/or subconscious selection during century, the stimulation of rat acceleration may be explained by the ‘increase in living space and resources’ due to improved standards for keeping animals in the modern period (fewer animals in the cage or even an individual cage). In random-bred animals such standards can be apply for economic reasons to a lesser extent. Conclusions: It is concluded that the physiological, anatomical, possibly behavioral and other standards and patterns for strain rats, including, possibly, its radiosensitivity, published even 30 years ago, and especially more than 50 years ago, should be cautiously transferred to the animals grown under present-day conditions.