Mutagenicity monitoring of airborne particulate matter (PM10) in the CzechRepublic

The mutagenic activities associated with inhalable airborne particulate mat ter (PM10) collected over a year in four towns (Czech Republic) have been d etermined. The dichloromethane extracts were tested for mutagenicity using the Ames plate incorporation test and the Kado microsuspension test both wi th Salmonella typhimurium TA98 and its derivative YG1041 tester strains in the presence and absence of S9 mixture. The aim of this study was to assess the suitability of both bacterial mutagenicity tests and to choose the app ropriate indicator strain for monitoring purposes. To elucidate the correla tion between mutagenicity and polycyclic aromatic hydrocarbons (PAHs), the concentration of PAHs in the air samples were determined by GC/MS. In gener al, the significant mutagenicity was obtained in organic extracts of all sa mples, but differences according to the method and tester strain used were observed. In both mutagenicity tests, the extractable organic mass (EOM) ex hibited higher mutagenicity in the YG1041 strain (up to 97 rev/mu g in the plate incorporation and 568 rev/mu g in the microsuspension tests) than tho se in TA98 (up to 2.2 rev/mu g in the plate incorporation and 14.5 rev/mu g in the microsuspension tests). In the plate incorporation test, the direct mutagenic activity in YG1041 was on average 60-fold higher and in microsus pension assay 45-fold higher with respect to strain TA98. In the presence o f S9 mix, the mutagenic potency in YG1041 declined (P < 0.001) in summer, b ut increased in TA98 (P < 0.05) in samples collected during the winter seas on. The microsuspension assay provided higher mutagenic responses in both t ester strains, but in both strains a significant decrease of mutagenic pote ncy was observed in the presence of S9 mix (P < 0.001 for YG1041, P < 0.05 for TA98 in winter). The mutagenic potencies detected with both indicator s trains correlated well (r = 0.54 to 0.87) within each mutagenicity test use d but not (for TA98) or moderately (r = 0.44 to 0.66 for YG1041) between bo th of the tests. The mutagenic activity tin rev/m(3)) likewise the concentr ation of benzo[a]pyrene and sum of carcinogenic PAHs showed seasonal variat ion with distinctly higher values during winter season. A correlation betwe en the PAH concentrations and the mutagenicity results for the plate incorp oration, but not for the microsuspension tests was found. In samples from h igher industrial areas, the higher mutagenicity values were obtained in pla te incorporation test with TA98 and in both tests with YG1041 in summer sea son (P < 0.05). According to our results, plate incorporation test seems to be more informative than microsuspension assay. For routine ambient air mu tagenicity monitoring, the use of YG1041 tester strain without metabolic ac tivation and the plate incorporation test are to be recommended. (C) 1999 E lsevier Science B.V. All rights reserved.