Accelerator mass spectrometry (AMS) was shown to be applicable for studying the penetration of organic aerosols, inhaled by laboratory mice at ultra-low concentration ca. 103 cm-3. We synthesized polystyrene (PS) beads, composed of radiocarbon-labeled styrene, for testing them as model organic aerosols. As a source of radiocarbon we used methyl alcohol with radioactivity. Radiolabeled polystyrene beads were obtained by emulsifier-free emulsion polymerization of synthesized 14C-styrene initiated by K2S2O8 in aqueous media. Aerosol particles were produced by pneumatic spraying of diluted 14C-PS latex. Mice inhaled 14C-PS aerosol consisting of the mix of 103 225-nm particles per 1 cm3 and 5·103 25-nm particles per 1 cm3 for 30 min every day during five days. Several millions of 225-nm particles deposited in the lungs and slowly excreted from them during two weeks of postexposure. Penetration of particles matter was also observed for liver, kidneys and brain, but not for a heart.