Evaluation of bioaerosol concentrations in PM ₁₀ and analysis of environmental impacts in windy and dusty regions of eastern Iran

In this study, bacterial and fungal bioaerosols concentration in particulate matter (PM) was estimated during the year 2022, with special emphasis on dusty days at the Zabol and Birjand cities of Iran. The association between bioaerosols and particulate matter to the different environmental variables was also investigated. This study finds that the average concentration of the particulate matter (PM₁₀) was higher at Zabol city (478 ± 280 µg/m³) as compared to the Birjand (105 ± 49 µg/m³) throughout the year during sampling. For bioaerosols, it followed the same trend, as it was 801 ± 1041 CFU/m³ and 368 ± 214 CFU/m³ (bacteria) and 175 ± 158 CFU/m³ and 143 ± 81CFU/m³ (fungi) for Zabol and Birjand, respectively. Moreover, the concentrations of particulate matter and associated microbes were found higher during or after the dust events. The maximum wind speed (WS_max) showed the significant positive correlation with the PM₁₀, (i.e. Zabol (r = 0.725) and Birjand (r = 0.557)). The HYSPLIT back trajectory analysis shows the westerly prevailing wind can be the major source particulate matter during the dust events in this area. The results of this study show the importance of dust events in Iran and associated health impacts.