Effect of space flight on the levels of volatile metabolites in the exhaled air of astronauts

: 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.