Abstract: The mutagenicity of airborne particulates from differential function districts in Shenyang was studied with salmonella typhimurium strain TA98, the classically beliered sensitive strain, and its new derivative strains TA98NR, TA98/1 ,8DNP6, YG 1021 and YG1024,and sensitivity of these new strains were compared with that of TA98.The results indicated that the mutagenicity of samples for YG1024,YG1021 and TA98 were significantly stronger than that for TA98NR and TA98/1, 8DNP₆.Strain YG1024 was more specific to the mutagenicity of samples than TA98.This strongly suggests the presence of nitrated polycyclic aromatic hydro-carbons (NO₂-PAHs)in these particulates and that nitropyrenes must be the major direct-acting mutagens, especically dinitropyrenes (DNPs) .YG1024 can become the ralatively sensitive indicating strain in detecting mutagenicity of samples of environment.The results indicated samples from industrial and residential districts contained more NO₂-PAHs than that from other districts.

Key words: airborne particulate, mutagenicity, Ames test, nitrated polycyclic aromatic hydrocarbons ( NO₂-PAHs)