Purpose: To summarize data on graduation of the effect size on the base of Hill’s first causality criterion ‘Strength of association’ on relative risk parameters (RR). Material and methods: Survey of published sources: monographs, handbooks, papers, educational material on statistics in various disciplines (including on-line), etc. (128 references; of which about 30 handbooks on epidemiology, carcinogenesis and medical statistics). Results: For the RR value, the collected data summary (1980–2018) implies non-homogeneity in concepts. The most common references are to the Monson scale (two editions of the monograph on the epidemiology of occupational exposures Monson R.R., 1980; 1990). In our opinion, the optimal graduation can be developed on the basis of this scale, and it should include both the range of no effect (RR = 0.9–1.2) and the weak (RR = 1.2–1.5, or 0.7–0.9), moderate (RR = 1.5–3.0, or 0.4–0.7), strong (RR = 3.0–10.0; or 0.1–0.4) and very strong’(RR = 10.0–40.0; or 0.0–0.1) ranges. Examples of epidemiological effects with overwhelming strength of association are presented (RR > 40.0). For the effects of thalidomide, RR reached thousands, for diethylstilbestrol, conditional infinity, and when irradiated in childhood, the frequency of some cancers increased tens and even hundreds of times. The juristic aspects of compensation payment based on RR are briefly reviewed. According to the Daubert rule (Daubert ruling, Daubert standard) on the 1993 precedent in the United States, risks are recognized only at RR > 2.0, when the probability of causality is more than 50 %. Conclusions: To estimate the RR value, one should use the most common and officially established Monson scale, albeit with an expansion in the range of dramatic or overhelming risks. This study can be used as a reference guide on the graduations of effect size on RR (OR) for a wide variety of observed disciplines.

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: Survey-synthetic study of published scientific data on the relationship between the ages of the most used laboratory animals (mice, rats, hamsters and dogs) and humans to obtain the corresponding formula dependencies and calibration curves. Basis: The work is a preamble for a more extensive analysis of data on the age-related radiosensitivity of animals as applied to the extrapolation of the revealed patterns to humans. The presented introductory review of the history of research in this field showed that the main works were carried out in the 1950s – 1960s, and, much less, in the 1970s, and the results, apparently, produced almost nothing for practical radiation medicine and radiation safety. Investigations of the relationship between the age and the radiosensitivity for the human which were exposed to total irradiation in significant doses were practically not found although such data are important because of the permanent threat of nuclear incidents and terrorism. In this regard, the quantitative transfer of the corresponding dependencies, identified for various species of animals, on the situation with acute human radiation syndrome continues to be relevant. In its entirety, according to our analysis of sources it has not been carried out until now, including the documents of UNSCEAR, ICRP, WHO, and others. Material and methods: Data on physiological age periods and their boundaries for animals and humans, published in reliable scientific sources, were used for calculations and general analysis. Based on the extracted values (from tables and one chart of originals), using the IBM SPSS and Statistica programs, a formula was derived for the ‘standard’ dependencies on ‘age of the animal – age of the human’ and a corresponding calibration schedule was constructed. Both direct and indirect data were used. In the first case (mice, rats, dogs) we used the data for direct comparison of the age periods of animals and humans and in the second (mice, rats, hamsters) we used the quantitative information about a particular age period for an animal. It allowed us to conduct own comparison of such data with a similar period of human life. Results: ‘Standard’ formulas were derived and ‘standard’ calibration curves were obtained, which made it possible to compare the age of mice, rats, hamsters and dogs with human age. In parallel, it turned out that many of the so-called ‘calculators’ in the English and Russian-language Internet, which can translate the age of almost any animal into human age (according to the statements of their developers), give the mistakes at comparative estimates with the observed dependencies on the basis of scientific data (difference up to 20–60 %). Conclusions: The obtained data fill the existing scientific gaps, creating the prerequisites for both comparison of the parameters of the age-related radiosensitivity of laboratory animals and humans (important for radiation safety) and for use in other experimental areas of biomedical disciplines. On the basis of detailed approaches to the problem considered in the paper, it is possible to derive similar relationships for the age of any other animal and human.

For random-bred albino rat and for eight most known rat lines (Wistar, Wistar Hannover, Wistar Kyoto, Sprague Dawley, Lewis, Fisher 344, Lister and Long-Evans) a brief review of the origins and features was made, and data on the age–weight dependences in norm obtained from experimental works and presented in the materials of firms and nurseries were analysed. The data extracted from the sources by digitizing the original curves or taken from there from the tables were combined (Mean ± 95% Confidence Intervals), and the values were compared in parallel along the Student’s t-test and the Mann–Whitney U-test. For half the rat lines (males and females) it was found that the body weight growth in works and nurseries does not coincide (statistically significant or in the form of distinct trends), and the discrepancy can began either from a certain time moment (Wistar Hannover, Sprague Dawley), or almost immediately after birth (Lewis, Long-Evans). The detected phenomenon has practical significance for the object selection for radiosensitivity investigation. Differences in age at the same weight of animals in the experiment and in nurseries can cause errors in background radioresistance. A review of the studies on dependence of the radiosensitivity on the age of irradiated rats was performed with the reproduction of a number of published data in a graphic form and it was concluded that a mistake in the age of rats even for a few weeks can strongly affect the radiosensitivity. It is noted that the importance of taking into account the body mass index is due to the dependence on it of the mass of internal organs, the magnitude of which is affected, among other things, on the results of internal dosimetry. Distribution by growth intensity (an age of achievement of weight 200 g) for males is follows: Wistar > Sprague-Dawley = Lister > Long-Evans (from nurseries) > Wistar Hannover > Lewis > Wistar Kyoto > Fisher 344 > Long-Evans (from works) > Wistar from 1906–1932 > random-bred albino. As a result of the study, standard, tabular growth curves for random-bred rat and eight mentioned rat strains obtained by combining and statistical processing of data from all available sources were also presented. This material continues the traditions of Donaldson’s Tables (H.H. Donaldson, 1915) and the growth standards for laboratory animal lines in work of S.M. Poiley (1972). The report of the individual data by some characteristics of a rat species is presented: average life expectancy, age and weight for various physiological periods of the development, and also a certain ‘standard’ weight for a rat as a species.

No abstract