The adsorption of substances in human serum on mineral dusts was studied by measuring the composition of the serum after the adsorption and using infrared spectra. The results suggest that the adsorption of substances in human serum on mineral dusts is selective and that the adsorpted substances are mostly biological macromolecules in the serum, such as protein and lipids. Infrared spectra have shown that the adsorption mechanism is mainly physical adsorption and that there is possibly chemical adsorption. The adsorption selectivity of biological macromolecules on varying minerals in the serum is mainly related to the structure and surface activity of the minerals. On the other hand, the cationic exchange and dissolution of mineral dusts occur in the human serum to some extent.