Determination of mutagenicity of PM2.5 samples collected at Bolu city center

Airborne particulate matter (PM), including many inorganic and organic chemicals in both the solid and liquid states, is present in the atmosphere as a suspension. The chemical composition of PM is variable and is mainly composed of metals, hydrocarbons, ions, and microorganisms. PM with an aerodynamic diameter of less than 2.5 µm (PM2.5), which is inhaled and deposited deeper into the respiratory system, has significant adverse health impacts. Polycyclic aromatic hydrocarbons(PAHs) are widely present in environmental matrices and released into the atmosphere from the incomplete combustion of natural and anthropogenic organic matter. These pollutants are accepted as a global problem because they can btransported over a long range in the atmosphere and have mutagenic and carcinogenic effects. While these pollutants are not routinely monitored, the identification of their environmental impacts is significant for mitigating these pollutants. In this study,daily PM2.5 samples were collected employing a high volume sampler on quartz filters between July and August 2017 and February to March 2018 at a station located in the city center of Bolu. The average PM2.5 mass concentration during this period was determined as 19. 05 ±14.76 µg/m3. The total average PAH concentration was found as 18.67±33.23 ng/m3 during the study period, and it ranged from 4±10 pg/m3(Ace) to 4.86±13.61 ng/m3 (Ind).Benzo(a)pyrene (BaP) was the only PAH compound that is monitored in Turkish Air Quality Evaluation and Management Regulation. For this reason, the samples in which BaP concentration was found to be > 1.0 ng/m3 and total PAH concentration > 12 ng/m3 were selected and the Ames test was conducted on these samples to determine the impact of PAHs. The Ames test was performed on the selected samples to assess the mutagenicity of the PAHs in the human body. In this study, two tester strains of Salmonella typhimurium (his-) TA98 and TA100 were used with and without S9 mix metabolic activation. The results showed that the metabolic activities of PAH compounds decreased because of metabolic reactions that take place in human body. To our best knowledge, this study is the first in Türkiye study reporting the mutagenicity of atmospheric PAH compounds by using the Salmonella typhimurium strains.