Wintertime investigation of PM₁₀ concentrations, sources, and relationship with different meteorological parameters

Meteorological factors play a crucial role in affecting air quality in the urban environment. Peshawar is the capital city of the Khyber Pakhtunkhwa province in Pakistan and is a pollution hotspot. Sources of PM₁₀ and the influence of meteorological factors on PM₁₀ in this megacity have yet to be studied. The current study aims to investigate PM₁₀ mass concentration levels and composition, identify PM₁₀ sources, and quantify links between PM₁₀ and various meteorological parameters like temperature, relative humidity (RH), wind speed (WS), and rainfall (RF) during the winter months from December 2017 to February 2018. PM₁₀ mass concentrations vary from 180 - 1071 µg m^-3, with a mean value of 586 ± 217 µg m^-3. The highest concentration is observed in December, followed by January and February. The average values of the mass concentration of carbonaceous species (i.e., total carbon, organic carbon, and elemental carbon) are 102.41, 91.56, and 6.72 μgm^-3, respectively. Water-soluble ions adhere to the following concentration order: Ca²⁺  > Na⁺  > K⁺  > NH₄⁺  > Mg²⁺. Twenty-four elements (Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Co, Zn, Ga, Ge, As, Se, Kr, Ag, Pb, Cu, and Cd) are detected in the current study by PIXE analysis. Five sources based on Positive Matrix Factorization (PMF) modeling include industrial emissions, soil and re-suspended dust, household combustion, metallurgic industries, and vehicular emission. A positive relationship of PM₁₀ with temperature and relative humidity is observed (r = 0.46 and r = 0.56, respectively). A negative correlation of PM₁₀ is recorded with WS (r =  - 0.27) and RF (r =  - 0.46). This study's results motivate routine air quality monitoring owing to the high levels of pollution in this region. For this purpose, the establishment of air monitoring stations is highly suggested for both PM and meteorology. Air quality standards and legislation need to be revised and implemented. Moreover, the development of effective control strategies for air pollution is highly suggested.