Geomagnetic storm under laboratory conditions: randomized experiment.

The influence of the previously recorded geomagnetic storm (GS) on human cardiovascular system and microcirculation has been studied under laboratory conditions. Healthy volunteers in lying position were exposed under two artificially created conditions: quiet (Q) and storm (S). The Q regime playbacks a noise-free magnetic field (MF) which is closed to the natural geomagnetic conditions on Moscow's latitude. The S regime playbacks the initially recorded 6-h geomagnetic storm which is repeated four times sequentially. The cardiovascular response to the GS impact was assessed by measuring capillary blood velocity (CBV) and blood pressure (BP) and by the analysis of the 24-h ECG recording. A storm-to-quiet ratio for the cardio intervals (CI) and the heart rate variability (HRV) was introduced in order to reveal the average over group significant differences of HRV. An individual sensitivity to the GS was estimated using the autocorrelation function analysis of the high-frequency (HF) part of the CI spectrum. The autocorrelation analysis allowed for detection a group of subjects of study which autocorrelation functions (ACF) react differently in the Q and S regimes of exposure.

Effect of zero magnetic field on cardiovascular system and microcirculation.

The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling "ARFA" has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.

METHOD FOR ANALYSIS OF HEART RATE REGULATION STRAIN BY APPLICATION OF THE OVERALL LOGARITHMIC INDEX TO THE HOLTER ELECTROCARDIOGRAM MONITORING.

Studies of human adaptation to extended exposure in extreme environments necessitate the development of integral indexes for quantitative evaluation of the functional systems of organism. The study was performed using an integral overall logarithmic index to analyze changes in heart rate variability (HRV)' over 20-hour monitoring of patients examined in a hospital. HRV-evidenced adaptation processes were compared to the data of Holter monitoring of patients and normal values for healthy people under 30 years of age.

[Evaluation of the hypomagnetic environment effects on capillary blood circulation, blood pressure and heart rate].

Impact of attenuated magnetic field (MF) on human health is a hard-core issue of present-day cosmonautics. A series of experiments with animals exposed in attenuated MF revealed violent disorders in cardiovascular system development. Purpose of the work was to study effects of the hypomagnetic environment (HME) on capillary blood circulation, blood pressure (BP) and heart rate (HR) in normal people. Participants (n = 34) were 24 men and 10 women free from cardiovascular symptoms. Mean age was 43.3 +/- 15.4 years. Thirteen participants, i.e. 8 men and 5 women, were randomly selected for a repeated investigation in the usual conditions (imaginary exposure); mean age in the group made up 47.9 +/- 18 years. Cardiac rhythm and heart rate were recorded using cardiac monitor Astrocard (Russia). BP was measured with the help of automatic blood pressure monitor Tonocard (Russia). Capillary circulation was determined using a digital capillaroscope (Russia) with high-speed CMOS-camera (100 frames/s). Time of HME exposure was 60 min. It was demonstrated that in healthy people free from cardiovascular symptoms HME increases capillary circulation rate by 22.4% as compared with records made under the usual conditions. There was a reliable HR reduction by the end of HME exposure with reference to the measurements taken at the onset. At the end of exposure, diastolic BP dropped considerably relative to mid-exposure values and systolic BP, on the contrary, made a significant rise.

[Overall logarithmic index for the characterization of adaptation and regulatory systems straining under chronic action of extreme environmental factors].

The article advertizes some optional capabilities of the overall logarithmic index as an integral parameter for quantifying adaptation processes triggered by chronic exposure to stress factors of varying intensity. Consideration is given to the principles of damage formation in different systems of organism with time and subsequent compensatory processes depending on the level of regulation system straining, rate of functional potential depletion, probability of remote consequences such as early aging, increased risk of lethality and reduction of the mean remaining life expectancy. The overall logarithmic index will be used to analyze the transition from normal to active insufficient adaptation, and possible adaptation failure because of a drastic decline of organism resistance. In fact, an attempt was made to use the index to quantify adaptation cost, loss of resistance, and possible increase of the risk of remote consequences.

[The quantitative criteria of the transition from norm to pathology at chronic exposure of physical factors].

In this work the quantitative approaches for the characteristic of the change in the condition of separate systems and stability of an organism are considered at chronic exposure of electromagnetic fields of a radio-frequency range. The quantitative criteria for the substantiation of transition from norm to pathology and definition of the thresholds of harmful action of physical factors are developed. The results of the experimental research of the immune system condition at EMF RF exposure were considered. It can be a basis for the definition of maximum permissible levels of these factors for professional workers and for the population.

[Biological effects of microwave radiation of low nonthermal intensity (regarding the maximal admissible values)].

There is still much controversy in scientific approaches to setting limits of exposure to radio-frequency electromagnetic radiation in Russia, Europe and USA. The stumbling stone is recognition or denial of potential risk of biological effects from nonthermal electromagnetic radiation (to 1 mW/cm2). The authors review results of experimental investigations performed in Russia over the years since 1960s to study the direct and delayed effects of ultra-high and microwave frequencies of low non-thermal intensity EMR, and delayed negative effects in employees based on the data of several follow-up epidemiological studies. This evidence was used as a baseline for establishing the Russian limits for chronic exposure to, thresholds of harmful effects and the maximal admissible values of EMR within the above frequencies.

[Bioeffects of chronic exposure to radiofrequency electromagnetic fields of low intensity (standardization strategy)]. / Bioéffekty khronicheskogo vozdeistviia élektromagnitnykh polei radiochastotnogo diapazona malykh intensivnostei (strategiia normirovaniia).

A retrospective analysis of the experimental researches on the effect of radio frequency electromagnetic fields (EMF) on human health, carried out in the USSR, is presented. The results of chronic exposure of laboratory animals to EMF have been considered. Apparently, EMF in the range of 1750-2750 MHz with power density up to 100-500 W/cm2 caused in immune globullin fractions, and a development of autoimmune processes. The changes in parameters of reproductive functions and posterity, the increase in embryo mortality were found. The standartization strategy used in the USSR and currently applied in Russia has been discussed.

[The remote effects of chronic exposure to ionizing radiation and electromagnetic fields with respect to hygienic standardization]. / Otdalennye éffekty khronicheskogo vozdeistviia ioniziruiushchego izlucheniia i élektromagnitnykh polei primenitel'no k gigienicheskomu normirovaniiu.

A variety and rate of non-cancer diseases occurred in humans as a result of chronic exposure to ionizing radiation or to electromagnetic radiation (EMR) of high and superhigh frequency have been compared. The intensity of EMR was slightly higher than a sanitary standard for population. A risk of health impairments in workers having occupational exposure to EMR was assessed on the basis of Selie's concept of development of non-specific reaction of the body to chronic stress factors (general adaptation syndrome), models of changes in the body compensatory reserves and calculations of radiation risk after severe and chronic exposure to ionizing radiation.

[Some aspects of animal-to-human approximation of low frequency electromagnetic field exposure conditions]. / Nekotorye voprosy perenosa uslovii vozdeistviia nizkochastotnykh élektromagnitnykh polei s zhivotnykh na cheloveka.

Appropriateness of representation of a biological object surface as an equipotential surface has been proved for conditions of a quasistatic exposure to EMF of frequencies lower than 1 MHz. The conditions, at which a self capacitance of a biological object is its basic electrical parameter, have been considered. A factor of animal-to-human approximation of low-frequency EMF exposure conditions was estimated on the basis of equal dose loading in biological objects of different geometric sizes.

[Assessment of the contribution of broadband quasi-continuous electromagnetic background to dose loading]. / Otsenka vklada shirokopolosnogo kvazinepreryvnogo élektromagnitnogo fona v dozovuiu nagruzku.

Assessment of probable dose loading due to a broadband quasi-continuous electromagnetic background is presented. A level of the quasi-continuous background in the appropriate frequency intervals could exceed maximum permissible exposure by a factor of several tens. For safety monitoring, it is suggested to use the equipment that allows registering of EMF amplitude and frequency in a wide frequency range, with sensitivity by order of magnitude greater than MPE.

[The effect of the pulsed radiation of a fast electron beam on the fluorescence of solutions of biological molecules]. / Vliianie impul'snogo izlucheniia puchka uskorennykh élektronov na fluorestsentsiiu rastvorov biologicheskikh molekul.

The intensity of fluorescence of amino acid and globular protein solutions, exposed to a pulsed electron beam in the presence and absence of the concurrent pulsed electromagnetic field was found to be a function of radiation dose. The observed decline in the fluorescence intensity was slightly dependent on the solution concentration and dependent on the time and dose-rate of irradiation. The effect of the concurrent pulsed radiation of the electromagnetic field was sometimes observed.