HUMAN'S BREATH DURING MODELED PROLONGED HYPODYNAMIA.

Low-molecular volatile metabolites were studies in breath of healthy human subjects exposed to prolonged hypodynamia and verified as potential biomarkers of hypoxia in skeletal muscles and myocardiur by comparison with energy metabolism biochemical indices. cs) was explored Profile of volatile organic compounds (VOCs) was explored in breath of human subjects whose motor activities were limited due to 520-d isolation and connnemnerK nVIC - Analysis of detected voCs and comparison with dynamics of energy metabilism resulted in suggesting acetol as a potential breath biomarker of tissue hypoxia in skeletal muscles and myocardium. origination of acetol, the lactate precursor in methylglyoxal glucose oxidation, was hypothesized. It was shown that acetol decreases in consequence of low motor activity correlates with changes in biochemical indices of enzymes involved in energy metabolism and glycolysis, and also creatinine indicative of underloading the skeletal muscles. Decline in the activities of muscular and myocardial constellation enzymes during hypodynamia matches with the reliable dicrease in breath acetol.

[Cytogenetic investigations of mice marrow cells after isolated chronic exposure to radiation and chemical factors, and combined sequential exposure to these factors].

The article presents data on chromosomal aberrations in bone marrow cells of mice following isolated exposure to gamma-radiation and chemical factor within the existing MPCs for piloted spacecraft, and also combined sequential exposure in the ranges predicted for interplanetary missions. In the event of chronic exposure the relative number of chromosomal aberrations goes up till reaching plateau and is governed strictly by the mathematical dependence on effective residual gamma-dose and effective damage of organism from inhaled chemical factor. Sequential exposure to the radiation and chemical factors within the ranges specified for orbital and remote space missions caused a tangible reduction of the speed of cytogenetic damages reparation in postexposure period which may be interpreted as depletion of the body reserve and compensatory-recovery potential.

[Adaptation processes in mice during chronic combined exposure to radiation and chemical compounds (acetone, ethanol, acetaldehyde) innate to exploration missions].

The paper reports the results of experimental investigation with mice subjected to 63-day of daily 10-fold fractionated gamma-irradiation at the total dose of 350 cGy followed by 70-day exposure to chemical mixture (acetone, ethanol, acetate aldehyde) at close to maximum permissible concentrations innate to piloted space vehicles (MPCpsv). Measured levels of radiation and known radiation sensitivity of mice were used to model absorbed dose to cosmonauts on an exploration mission. Functional shifts in the hematopoietic system and changes in biochemical parameters of erythrocytes indicative of energy exchange and redox potential were tracked up during the combined radiation-chemical exposure and 90 days of recovery. It was shown that adaptation caused pronounced and strongly pronounced tension of regulatory mechanisms, particularly under the effects of radiation. High tension still persisted in the recovery period.

[Evaluation of the risk of delayed adverse effects of chronic combined exposure to radiation and chemical factors with the purpose to ensure safety in orbital and exploration space missions].

The work had the aim to anatomize the existing issues with providing safety in extended orbital and exploration missions for ensuing estimation of actual values of the total radiation risk for the crew, and risks of other delayed effects of simultaneous exposure to ionizing radiation and chemical pollutants in cabin air, and a number of other stressful factors inevitable in space flight. The flow of chronic experiments for separate and combined studies with reproduction of air makeup and radiation doses in actual orbital and predicted exploration missions is outlined. To set safety limits, new approaches should be applied to the description of gradual norm degradation to pathologies in addition to several generalized quantitative indices of adaptation and straining of the regulatory systems, as well as of effectiveness of the compensatory body reserve against separate and combined exposure.

[Results of salad machine experiment within the MARS-500 project].

The salad machine experiment was aimed to fulfill performance testing of a prototype of space conveyor-type cylindrical greenhouse PHYTOCYCLE-SL, to study growth and development of plants, and to evaluate microbial contamination of equipment in the closed manned environment. Crops of leaf cabbage Brassica chinensis L., cultivar Vesnianka were raised in the time interval between MARS-500 days 417 and 515. The greenhouse proved it serviceability demanding 17 min/(man x d) in the normal mode. Most likely that the slow growth rate and deviations in plant morphology were caused by the presence of volatile pollutants in the greenhouse compartment Accumulation of micromycetes was observed at the sites of humid surfaces contact with ambient air; reduction of the artificial soil area contacting with air decreased population of micromycetes in 40 times. Cabbage leafs were free of pathogenic microflora. These results of the experiment helped develop recommendations on how to work out some units and systems in projectable greenhouse VITACYCLE-T

[Volatile metabolites in expired air of humans during 5-day dry immersion].

Both gas chromatography and mass-spectrometry were used to analyze make-up of air expired by 7 human subjects in a dry immersion (DI) experiment simulating some of the effects of microgravity. It was found that 5-d DI produces significant increases in expired amines, chiefly butylamine, 2-cyanacetimide, some aldehydes (isobutyl aldehyde, benzaldehyde), polyols (ethylene glycol, butyldiol), phenol, phenyl acetylene, ketones (methyl-ethyl-ketone), butylacetate and a significant decrease in fatty acids.

[Equipment for biological experiments with snails aboard piloted orbital stations].

To fly biological experiments aboard piloted orbital stations, research equipment was built up of an incubation container, filter system and automatic temperature controller. Investigations included analysis of the makeup and concentrations of gases produced by animals (snails) during biocycle, and emitted after death. Filters are chemisorption active fibrous materials (AFM) with high sorption rate and water receptivity (cation exchange fiber VION-KN-1 and anion exchange fiber VION-AS-1), and water-repellent carbon adsorbent SKLTS. AFM filters were effective in air cleaning and practically excluded ingress of chemical substances from the container into cabin atmosphere over more than 100 days.

[Effect of plant-associated methanolic bacteria on methane and methanol concentration dynamics in atmosphere of pressurized chamber].

Stability of Chinese cabbage crop colonization by methanolic bacteria Methylovorus mays, Methylomonas methanica and Methylosinus trichosporium inoculated using a space-applicable method was evaluated. Besides, trends of methane and methanol concentrations in the pressurized chamber with inoculated and uninoculated crops were calculated. Methylovorus mays and Methylosinus trichosporium were shown to establish more stable colonization as compared to Methylomonas methanica. Also, stable association of methanolic bacteria with plants reduced airborne methanol 75% faster owing to its uptake by bacteria. Therefore, inoculation of these microorganisms can be viewed as a promising method of controlling volatile pollutants in space vehicle atmosphere. Methane drop after 6-hour exposure to inoculated control and test crops was not significant.

[Characteristic of toxic risks of air pollution by chemical admixtures aboard the piloted orbital stations].

Trends in the chemical composition of air revealed by the sanitary-chemical and toxicological investigations in multifactorial ground-based tests and long-term space flights aboard the Salyut- 6, 7, Mir and the International space station have been used to deduce the chemical characteristic and to substantiate methods to and criteria for evaluation of toxic risks to space crews from air chemical pollution. Of particular concern were the toxic risks and crew protection during the first ingress to modules on the stage of station assembly in orbit, in the course of long-term missions, and in the event of acute exposure in off-nominal and emergency conditions.

[A promising method of hygienic evaluation of air pollution inside the modules of the international space station by hydrazine derivatives].

The increasing frequency of ISS egress operations resulted in ISS air pollution by an uncharacteristic group of toxic compounds, i. e. propellant residues and products of propellant incomplete burning. High reactivity and toxicity of these compounds necessitated the development of a method of sanitary-chemical evaluation of ISS air safety given penetration of the new pollutants. The method is fulfilled in two stages. First is air sampling and then--sample analysis in ground laboratory by chromatography-mass spectrometry. Air sampling, as well as sample handling and analysis procedures were refined with the use of artificial gas mixtures. The proposed method shows promise as an instrument for the hygienic evaluation of ISS air pollution by hydrazine derivatives.

[Chromosomal aberrations upon isolated and combined exposures to chemical substances and ionizing irradiation].

The partial summation of biological effects evaluated by the anaphasic chromosomal aberration test in the bone marrow karyocytes of mice was determined when the animals were concurrently exposed to chemical substances (acetone, acetaldehyde, ammonia, and ethanol) at low concentrations and gamma-irradiation in a total dose of 30 Gy. Qualitative analysis of chromosomal aberrations in the karyocytes of the bone marrow (ponses, fragments) has indicated that upon combined exposure of the animals to the chemical substances and gamma-irradiation, the chemical factor is dominant since upon combined radiochemical exposure, the number of chromosomal aberration increases mainly at the expense of fragments (91.2%), as does upon isolated exposure to chemical substances (96.4%).

[Cytogenetic and biochemical reactions of experimental animals to combined exposure to low-intensity radiation and chemical factors].

Combined exposure of mice to a mixture of chemicals in small quantities and gamma-radiation at a total dose of 30 sGy cause partial summation of biological effects assessed by cytogenetic disorders in nuclear cells of the bone marrow and changes in erythrocyte metabolism. The level of cytogenetic damages in bone marrow cells remained increased till day 14 of recovery, whereas following exposure to chemicals or radiation alone the number of chromosomal aberrations (ChA) was nearly same as in control at this point of recovery The anaphase method showed prevalence of ChA in the form of fragments over bridges in marrow karyocites. The combination of factors suppressed energy-producing processes in erythrocytes (reliable reductions in lactate dehydrogenase and lactate) and activated oxidation processes (reliable decrease in reduced glutathione). Functional shifts in erythrocyte metabolism persisted till day 30 of recovery Based on results of the investigation, functional status of organism following low-intensity exposures can be assessed, along with cytogenetic, also by indices of erythrocyte metabolism.

[Air quality monitoring on the International Space Station].

Chemical contamination of air in space cabins occurs mainly due to permanent offgassing of equipment and materials, and leaks. Methods and means of qualitative and quantitative air monitoring on the ISS are powerful enough as for routine so emergency (e.g. local fire, toxic leak) air control. The ISS air quality has suited to the adopted standards and crew safety requirements. Yet, there is a broad field of action toward improvement of the space cabin air monitoring.

[The combined action of octafluoropropane and bipolar ionized air].

An experiment with Wistar male rats was to look into the action of octafluoropropane (OFP, of 50 microg/m(3)) combined with bipolar ionized air (BIA) at a concentration of light air ions of 60,000 para-air in cm(3). The chamber experiment was 43 days long. Intoxication by OFP reduced body mass, as well as the erythrocyte count and hemoglobin level in peripheral blood. As for BIA, it appeared to bring these indices back to their normal values. Erythrocyte metabolism underwent phase-by-phase shifts; but breathing BIA mitigated these shifts markedly. As regards to erythrocyte metabolism in intoxicated animals, BIA had a compensatory effect Changes in the biochemical profile of blood plasma make us think, that BIA counteracts the OFP damaging action on the myocardium and, at the same time, aggravates impairment of metabolism in the liver and, probably, kidney. Variations in the spectrum and total content of higher fatty acids in the lung in the experiment were more pronounced in the event of exposure to OFP+BIA than to OFP alone. Also, the combined exposure increased the level of laurinic acid. Histological investigations of the liver, spleen, myocardium, trachea and the lung attested to the dystrophic damage of the liver, spleen plethora and reticular hyperplasia, and slight cloudy swelling of the myocardium attributed to OFP. After 14 days since the end of the experiment, histological changes were much less dramatic; in 39 days after the experiment all the changes were gone with the exception of weak emphysematosis. BIA had no effect on animals in the absence of OFP; neither was there any significant difference between control (intact) animals and those who breathed BIA in laboratory. To conclude, 50 microg/m(3) of OFP which falls far short of the existing maximum permissible levels, a strong toxic action on animals. Aside from mitigation of the OFP toxic action on erythrocytes and myocardium, BIA, when breathed with a long time, aggravated the metabolic disorders in the liver and lung provoked by OFP.

[Role of human olfaction in detection of space vehicle air contamination by gases emitted during thermal destruction of polymers].

The paper deals with the ability of human olfaction to identify odours associated with thermal destruction of polymers. The investigations confirmed the ability of early detection of equipment overheating and subjective odour evaluation using the 5-point intensity scale and calculating the relation of odour intensity to the maximum admissible concentration of volatile chemical contaminants aboard piloted space vehicles. Emission of gases by polymers in electrical equipment starts with heating temperature rise to 100 degrees C. A new odour smelled by only some of humans due to individual perception signifies typically that emitted gases are below MAC for space vehicle. Odour sensed by everyone though not irritating signifies, as a rule, of chemical contamination above MAC but not contingency. Symptoms of irritation by products of thermal destruction of polymers signify contingency and require the use of personal protection equipment.

[Octafluoropropane inhalation toxicity].

Wistar rats were used to study inhalation toxicity of octafluoropropane (OFP, freon-218) at the following concentration: 300 g/m3 (4-hrs), 30 g/m3 (0.5 to 4 hrs), 3 g/m3 (8 hrs), and 0.3 g/m3 (16 hrs). According to the histological analysis, OFP at the concentrations of 300 and 30 g/m3 had a politrophic toxic effect. Target organs were the lung, trachea, bronchus, heart, kidney, and the adrenaL There were dystrophic and necrobiotic lesions in the upper airways epithelium. Subacute and chronic vesicular bronchiolitis developed on days 7 and 14, respectively. Visceral organs and brain were found plethoric and the lung was found hemorrhagic. Similar lesions were seen in the trachea, bronchus, lung, liver, spleen, kidney, adrenal, heart, and the brain. Lipid redistribution was observed in the adrenal cortex and vascular reactions of renal tissue with juxtamedullar blood shunting. Toxicity of small OFP concentrations (3 and 0.3 g/m3) was distinguished by an extended aftereffect, these concentrations did not cause visible pathomorphologic changes but gave rise to an extended pathologic process detectable by biochemistry. In all concentrations, OFP impacted erythrocyte metabolism changing the lipid composition of cell membrane and activating membrane-bound adenosinetriphos-phatases. The activities of hepatocyte and myocardiac cytoplasmatic enzymes were altered in blood plasma. Increased malonic dialdehyde in blood plasma and decreased cell antioxidant GSH in erythrocytes suggested exaggerated lipid peroxidation. These data point to the necessity of revising the existing limits for OFP concentrations in air of populated areas, working areas, and closed human environments.

[The concept of hygienic evaluation of multicomponent chemical contamination of air on piloted orbital stations].

Air quality monitoring on piloted orbital stations (OS) showed that the multicomponent air contamination largely comes from technical sources defining the quantitative and qualitative dynamics and occasional sharp surges of contamination. Another pervasive factor is secondary, more toxic compounds resulting from transformation of chemicals. The toxico-hygienic qualification of the general chemical background should be made with reference to the next functional levels: bioneutral, threshold and admissible. Based on experiments, long-term presence of a multitude of airborne chemicals in trace concentrations or much below MACs (bioneutral) does not have an additive effect on human organisms and can be neglected in evaluation of the total toxicity of chemicals. Hygienic criteria should be set to the compounds that are liable to mount to the threshold and admissible concentrations. The concept of hygienic evaluation of multicomponent chemical contamination of OS air substantiates an integral estimation of the total chemical exposure of humans with good knowledge of effects of a combination of chemicals taken as the air quality markers, intermittent surges of contamination twice as high as time-average MACs, and intensity of secondary toxic contamination.

[Investigation of the process of personal hygiene items biodegradation by cellulose-fermenting microorganisms]. / Issledovanie protsessa biodegradatsii sredstv lichnoi gigieny mikroogranizmami-tseliulolitikami.

Cellulose-containing wastes are one of the heaviest and biggest ingredients of solid domestic wastes piling up during spaceflight. For the most part these are disposable personal hygiene items used in large quantities in the absence of shower. These wastes contain human body products which are very dangerous from the sanitary-epidemiological standpoint. The purpose was to explore potentiality of microbial biodegradation of cellulose-containing hygiene items anaerobically with dry mass transformation into liquid and biogas. Among specific objectives were test cultivation of active strains of reference cultures of cellulose-fermenting anaerobic thermophilic bacteria on hygiene items as the only source of carbon, evaluation of ways and need of pretreatment of gauze pads to stimulate biodegradation, and chemical analysis of resulting biogas. From the investigation it was concluded that gauze pads are susceptible to biodegradation by anaerobic bacteria producing a low toxicity gas fraction. Therefore, the proposed technology can be considered as a candidate for integration into the spacecrew life support system.

[Hygienic control of contingencies associated with local fire events aboard piloted orbital stations]. / Gigienicheskoe soprovozhdenie neshtatnykh situatsii, sviazannykh s lokal'nym vozgoraniem v usloviiakh pilotiruemykh orbital'nykh stantsii.

Based on the multiyear experience of hygienic control of the orbital stations, there are three causes of contingent air pollution: leakage of service system pipeline with chemical working bodies, spills of reagents used in biochemical and technological experiments, and air pollution by products of thermal oxidative degradation of nonmetallic materials. The authors describe their experience in successful elimination and prevention of hazardous consequences of fire aboard the space stations. Analysis of air pollution dynamics after actual fire events in the space station modules showed that it approximates a two-chamber air flow model with two phases of pollutant equilibration: first a rapid fall of concentration in the module on fire till air in the modules gets completely mixed, and then slow elimination of harmful pollutant from air. Identified were markers,--propylene and methylmetacrilate,--reacting to first signs of fire. Carbonic acid nitriles were recognized as toxic products of destruction. The positive effect of intermodular ventilation on dilution of toxic products of thermal oxidative destruction of materials was demonstrated. Satisfactory agreement of calculated and factual pollutant concentrations on board Mir permitted conclusion on applicability of the theoretical model to prediction of levels of air pollution due to contingency.

[Problems of environmental compatibility of the Russian and US segment of the International space station]. / Problemy sovmestimosti sredy obitaniia rossiiskogo i amerikanskogo segmentov Mezhdunarodnoi kosmicheskoi stantsii.

The problem of environmental compatibility of the ISS Russian and U.S. segments arises from chemical and biological inequality of their atmospheres and is attested by the data of observations during operation of Russian orbital stations Salyut and Mir. Efforts must be made to develop unified limits, and common procedures and requirements for evaluation of ISS materials and equipment by experts of the international partners.