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In recent years, the rising levels of atmospheric particulate matter (PM) have an impact on the earth's system, leading to undesirable consequences on various aspects like human health, visibility, and climate. The present work is carried out over an insufficiently studied but polluted urban area of Peshawar, which lies at the foothills of the famous Himalaya and Karakorum area, Northern Pakistan. The particulate matter with an aerodynamic diameter of less than 10 µm, i.e., PM10 are collected and analyzed for mineralogical, morphological, and chemical properties. Diverse techniques were used to examine the PM10 samples, for instance, Fourier transform infrared spectroscopy, x-ray diffraction, and scanning electron microscopy along with energy-dispersive x-ray spectroscopy, proton-induced x-ray emission, and an OC/EC carbon analyzer. The 24 h average PM10 mass concentration along with standard deviation was investigated to be 586.83 ± 217.70 µg/m3, which was around 13 times greater than the permissible limit of the world health organization (45 µg/m3) and 4 times the Pakistan national environmental quality standards for ambient PM10 (150 µg/m3). Minerals such as crystalline silicate, carbonate, asbestiform minerals, sulfate, and clay minerals were found using FTIR and XRD investigations. Microscopic examination revealed particles of various shapes, including angular, flaky, rod-like, crystalline, irregular, rounded, porous, chain, spherical, and agglomeration structures. This proved that the particles had geogenic, anthropogenic, and biological origins. The average value of organic carbon, elemental carbon, and total carbon is found to be 91.56 ± 43.17, 6.72 ± 1.99, and 102.41 ± 44.90 µg/m3, respectively. Water-soluble ions K+ and OC show a substantial association (R = 0.71). Prominent sources identified using Principle component analysis (PCA) are anthropogenic, crustal, industrial, and electronic combustion. This research paper identified the potential sources of PM10, which are vital for preparing an air quality management plan in the urban environment of Peshawar. [ABSTRACT FROM AUTHOR]

The transportation of atmospheric bacteria is increasingly recognized as an important factor that affects bacterial diversity in natural environments as well as human health. However, few studies have investigated airborne bacterial biodiversity in extremely remote, arid, and cold environments, such as desert and alpine areas, which may contain ambient bacteria transported by air masses. In this study, atmospheric aerosol samples were collected from the southern slope of the Himalayas, the southern Tibetan Plateau and the Mongolian Plateau to analyze the diversity of airborne bacteria and its relationship to environmental factors. The results show that the bacterial communities in all samples were predominantly composed of Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. Furthermore, the community structures of airborne bacteria exhibited significant differences among the collected sample, these differences mainly depended on meteorological parameters (P values < 0.01). In particular, the aerosol samples over the Tibetan Plateau showed the lowest diversity among the three regions. This suggests that the variability in airborne bacterial communities is determined by meteorological parameters and long-range transportation. Our study provides new information about airborne bacterial community composition in extreme environments and its large-scale spatial variability. • Actinobacteria and Firmicutes dominated in southern Tibetan Plateau samples. • The Tibetan Plateau showed the lowest diversity in airborne bacteria. • Meteorological factors and long-range transportation affected bacterial diversity. [ABSTRACT FROM AUTHOR]