The fatty acid spectrum of an expired air condensate was studied in the workers of the Kharanor coal stripping and in the dwellers of Chita (a control group). Regularities in the changes of the expired air fatty acid profile were assessed by the degree of exposure to coal dust and by the length of service. The findings indicated the relationship of profile changes with the degree of exposure to occupational noxious agents: the proportion of saturated fatty acids decreases much more significantly in workers who were directly exposed to the dust than in those were indirectly done. It is concluded that the fatty acid composition of an expired air condensate adequately reflects the changes occurring in the respiratory system upon exposure to dust.