[Toxicological evaluation of health risk of local fire in a closed environment]. / Otsenka toksikologicheskoi opasnosti lokal'nogo pozhara v germopomeshchenii.

Local fire in an enclosed environment was simulated, and the composition and toxicity of compounds outgassed by the polymers were investigated. Highly toxic compounds, e.g. prussic acid, carbon monoxide, benzene, nitrogen oxides, formaldehyde, were identified. The toxic hazard of the products depended on the mass and chemical composition of the burnt materials, time of exposure and enclosure volume. In the case of a local fire the enclosed atmosphere should be monitored by rapid diagnostic methods using indicator tubes.

[Effect of long-term anti-orthostatic hypokinesia on the composition of volatile metabolites in the exhaled air]. / Vliianie dlitel'noi antiortostaticheskoi gipokinezii na sostav letuchikh metabolitov v vydykhaemom chelovekom vozdukhe.

This paper presents measurements of volatile metabolites in the air exhaled by test subjects exposed to year-long antiorthostatic hypokinesia (-5 degrees). The test subjects were subdivided into two groups (Group A and Group B), which used different countermeasures. It was found that during the first 30 days of exposure exhalation of volatile metabolites reached a new and higher level. During test days 1 through 240 the content of volatile metabolites increased significantly in both groups; however the increase in Group B was less expressed than in Group A. At the final stage of the experiment, i.e. from day 240 through 370, the difference between the two groups was levelled off.

[Composition of exhaled air, gas and energy metabolism and bio- chemical indicators of the blood and urine in humans after long- term exposure to hypercapnia and hypoxia]. / Sostav vydykhaemogo vozdukha, gazoénergoobmen i biokhimicheskie pokazateli krovi i mochi u cheloveka pri dlite'nom nakhozhdenii ego v usloviiakh giperkapnii i gipoksii.

Four volunteers were enclosed for 40 days in a hypercapnic environment. Their average age was 41-59 years, body weight, 66-90 kg, and height 173-182 cm. During the study the ambient temperature was 19-23 degrees C, relative humidity, 50 +/- 20%; pO2, 19-19.5%; and pCO2, 1.3%. On test days 21-22 and 38-39 pCO2 was increased to 4% and pO2 was decreased to 17%. The time, within which pCO2 was increased to 4% on test days 38-39 when compared to test days 21-22, grew 1.5-fold and amounted to 40 hours. The subjects had three meals a day, consuming canned foodstuffs, the caloric value of which was 2982 kcal/day. In the study the following parameters were measured: malonic dialdehyde in venous blood; catalase, lactate, pyruvate, urea, acid-base content, gases in capillary blood; total nitrogen, ammonia, urea, creatinine and uric acid in 24-hour urine samples. Nitrogen balance and protein nutrition index were calculated. Results were processed using Student's t-test. During exposure lipid peroxidation increased and catalase decreased; malonic dialdehyde in blood increased, being correlated with lower hydrocarbons in exhaled air; gas and energy turnover during hypercapnic intervals enhanced. The above changes in the exhaled air composition, gas and energy turnover, biochemical blood and urine parameters remained within adaptation norm. By the second week of the recovery period the above parameters, except for nitrogen metabolism which remained slightly inhibited, returned to the normal.

[Thermoregulatory reactions of the human body to moderate hypercapnia]. / Termoreguliatornye reaktsii organizma cheloveka na umerennuiu giperkapnicheskuiu nagruzku.

Thermoregulatory reactions to sustained hypercapnia were investigated. Continuous 40-day exposure to hypercapnia (1.1-1.6% CO2 in the breathing air) in a thermoneutral area was accompanied by the development of a cooling effect that took the form of enhanced heat production beginning with exposure day 3. As the exposure to hypercapnia continued, lactate and excessive buffer bases in blood decreased, core temperature and heat content of the body declined. These changes suggest the limiting effect of hypercapnia in the above concentrations on thermogenesis, evidently at the stage of glycolytic ATP resynthesis.

[Reactions of the human body to chemical substances in an enclosed environment]. / Reaktsii organizma cheloveka na vozdeistvie khimicheskikh veshchestv v usloviiakn germoob" ektov.

The purpose of the study was to investigate adaptive responses of the human body to chemicals of anthropogenic origin in an enclosed environment. The object of the study was ammonia, a typical metabolite and a permanent contaminant of a enclosed atmosphere. The study consisted of a prolonged and continuous exposure to ammonia at a concentration of 2.0 +/- 0.1 mg/m3 and a 24-hour exposure to ammonia at a concentration of 9.8 +/- 0.1 mg/m3. The results showed that ammonia was neutralized in a stage-by-stage manner. At first the anthropotoxin was eliminated in exhaled air. As the exposure continued, additional mechanisms became involved, i.e. ammonia binding and renal excretion. Activation of ammonia detoxication occurred without noticeable involvement of the sympathoadrenal system.

[Effect of space flight on the levels of volatile metabolites in the exhaled air of astronauts]. / Vliianie kosmicheskikn poletov na soderzhanie letuchikh metabolitov v vydykhaemom vozdukhe kosmonautov.

The rate of expiration of volatile metabolites as a function of environmental factors is discussed. Concentrations of anthropotoxins in the air exhaled by cosmonauts before and after space flight as well as by test subjects exposed to prolonged antiorthostatic hypokinesia are presented. These observations show that after short-term and particularly after long-term space flights the concentrations of volatile metabolites in the exhaled air increased significantly. This suggests that space flight factors induce changes in the metabolic rate which has been to a certain extent confirmed by bed rest studies.

[Evaluation of the effect of enterosorption on the human body in a changed gaseous medium]. / Otsenka vliianiia énterosorbtsii na organizm cheloveka v usloviiakh izmenennoi gazovoi sredy.

The effect of enterosorption on biochemical and physiological parameters of 18 normal men was studied. The test subjects spent 7 days in an enclosed environment where the content of CO2 reached 3% and that of CO-40 mg/l3 during the last 8 hours of isolation. Beginning with the first day of enclosure 12 test subjects were given an enterosorbent at a dose of 0.75 g/kg 3 times a day. It is shown that a regular intake of an enterosorbent during exposure to increased concentrations of CO2 and CO affects beneficially central hemodynamics, reduces significantly plasma toxicity, content of C2-C5 hydrocarbons in the exhaled air and carboxyhemoglobin in blood. These findings may be very important for space and marine medicine because they demonstrate the efficacy of enterosorbents in protecting the human body from stress effects of an extreme environment.

[Interaction between chemical substances contaminating a gaseous medium of hermetically sealed compartments]. / Vzaimodeistvie khimicheskikh veshchestv, zagriazniaiushchikh gazovuiu sredu germozamknutykh pomeshchenii.

We have analyzed pertinent literature data and hypothesized that chemicals in an enclosed environment may interact (products of polymer outgassing, volatile metabolites of man). We have demonstrated that photochemical processes, thermochemical degradation and oxidation of chemicals in an enclosed atmosphere may lead to the formation of new highly toxic substances. The chemical composition of an enclosed atmosphere may be influenced by the technological processes of air purification. We have carried out experiments in a small enclosure to study ammonia and carbon dioxide interaction. When the concentration of ammonia is about 100 mg/m3, that of carbon dioxide is 2.5 vol. % and relative humidity of the atmosphere is 40-50%, the formation reaction of ammonia carbonate compounds proceeds very slowly, producing no significant changes in the environmental toxicological characteristics. It is recommended to continue the study of the interaction of chemicals at low concentrations in an enclosed environment.

[Effect of prolonged inhalation of acetic acid vapors on several human functional parameters]. / Vliianie dlitel'noi ingaliatsii parov uksusnoi kisloty na nekotorye funktsional'nye pokazateli cheloveka.

Test subjects were continuously exposed to acetic acid vapors which form a constant component of enclosed atmospheres. The inhalation time was 15 to 22 days at concentrations of 5, 10 and 15 mg/m3 or 10 days at a concentration of 26 mg/m3. Physiological parameters showed statistically significant changes at concentrations of 15 and 26 mg/m3. It is suggested that the changes are not adaptive but have been produced by the adverse effect of acetic acid vapors on the human body. It is therefore concluded that the 15 mg/m3 concentration is threshold and the 5 and 10 mg/m3 concentrations are ineffective in terms of the tests used. The most sensitive method is measurement of hydrocarbons (C2-C5), especially ethylene, in the exhaled air.

[Human blood glutamic acid in exposure to elevated ammonia levels in the gaseous environment]. / Glutaminovaia kislota krovi cheloveka pri vozdeistvii povyshennogo soderzhaniia ammiaka gazovoi sredy.

Amino acid metabolism of men kept in a enclosed environment was investigated. A high concentration of ammonia produced a specific redistribution of free amino acids in plasma with the content of glutamic acid increasing by the end of study. The estimates of glutamic acid in blood can be used for assessing maximally allowable concentrations of ammonia in enclosed environments.

[Change in the functional indices of animals during prolonged inhalation of acetic acid]. / Izmenenie funktsional'nykh pokazatelei u zhivotnykh pri dlitel'nom ingalatsionnom vozdeistvii uksusnoi kisloty.

Laboratory animals inhaled acetic acid vapors at a concentration of 86 to 27 mg/m3 for 3 to 35 days. It was found that the dose 36 mg/m3 inhaled for as long as 22 days constituted the minimal acting dose. The most sensitive parameters to be used in detecting the toxic effect of acetic acid were: treadmill run duration, open field activity, and ethylene, acetaldehyde and acetone concentrations in the exhaled air.

[Health and hygiene characteristics of the manned environment of the Saliut-7 orbital station]. / Sanitarno-gigienicheskaia kharakteristika sredy obitaniia orbital'noi stantsii "Saliut-7".

The Salyut-7 cabin environment was investigated with respect to the chemical, biological and physical factors. The gas composition was measured qualitatively and quantitatively. This determination showed a higher content of acetone and acetaldehyde when the cosmonauts worked on various trainers and unloaded the Progress cargo vehicles. The time-course study of the toxic impurities indicated that the increase in their content was transient (no more than 4 h). The microbial content was lower than in the Salyut-6 cabin environment. The study did not show a correlation between the microbial content in the environment and the time the prime crew remained onboard. There was a correlation between the microbial content, temperature variations, and conduct of certain experiments. On the whole, the Salyut-7 cabin environment was normal for the life and work of the crewmembers.

[Evaluation of the morphological status of the blood in humans during an exercise test in a hermetic chamber with various concentrations of ammonia]. / Otsenka morfologicheskogo sostava krovi u liudei pri fizicheskoi nagruzke v usloviiakh germokamery s razlichnoi kontsentratsiei ammiaka.

Test subjects were kept in an enclosure for 17-31 days. The ammonia concentration was maintained at 5.0 +/- 0.1 and 2.1 +/- 0.1 mg/m3 and elevated to 9.8 +/- 0.1 mg/m3 for a short period of time. Following each exercise test on a bicycle ergometer (at 50 and 75% VO2max) performed during this exposure the count of formed elements (leucocytes, neutrophils, lymphocytes, monocytes and platelets) increased as compared to the pretest level. The changes of most formed elements were within physiological variations. The exception was leucocytes, neutrophils, particularly rod neutrophils, and monocytes whose content was higher than normal at certain stages.

[Aerosol pollution of sealed manned quarters]. / Aérozol'nye zagriaznenie obitaemykh germetichnykh pomeshchenii.

The paper discusses the man's contribution to the formation of aerosol particles in manned enclosures. The data obtained in prolonged simulation studies suggest that man is the major source of aerosol contamination. The aerosol concentration and disperse composition are found to depend on the free volume per man. The paper presents for the first time the data on the rate of dust formation in manned enclosures.

[Effect of specific volume on formation of the atmosphere of hermetically sealed objects]. / Vliianie udel'nogo ob"ema na formirovanie vozdushnoi sredy germozamknutykh ob"ektov.

Atmosphere pollution with noxious gaseous trace contaminants exhaled by man in an enclosure was investigated as a function of free volume per man. The parameter was shown to depend on the environmental conditions: with increase in free volume the total level of atmosphere pollution decreased, being proportional to the concentration of gaseous trace contaminants in the exhaled air. Experimental curves of accumulation of gaseous chemicals exhaled by man were built.