Source Apportionment of PM10 at an Urban Site of a South Asian Mega City

Abstract

In the present study, analysis and source apportionment of the elemental composition of PM 10 was conducted in the urban atmosphere of Karachi. Trace elements such as Ni, Ba, Cd, Ca, Mg, Cr, Mn, Fe, Co, Cu, Sr and Ti were measured. The PM 10 concentration ranged from 255 μg m -3 to 793 μg m -3 , with an average of 438 ± 161 μg m -3 . Among the various elements analyzed, concentrations of Ca, Al and Fe were the highest (> 10000 ng m -3 ), followed by Mg and S (> 1000 ng m -3 ). Elements such as Zn, P, Cu, Pb, Mn, Ti, Sr and Ba demonstrated medium concentrations (> 100 ng m -3 ), whereas the lowest concentrations were found for elements such as Cr, Ni and Se (> 10 ng m -3 ). The Positive Matrix Factorization (PMF) model identified five possible factors that contributed to PM 10 , namely, biomass burning, coal combustion, resuspended road/soil dust, vehicular emissions and industrial dust. Industrial dust was the highest contributor (23.2%) to PM 10 followed by Biomass burning (23%), Vehicular emissions (22.2%), Coal combustion (21.7%) and Re-suspended dust (9.9%). A strong positive correlation (R 2 = 0.98) was observed between the model predicted PM 10 mass and the gravimetrically measured mass collected on filters.

Isotopic Interpretation of Particulate Nitrate in the Metropolitan City of Karachi, Pakistan: Insight into the Oceanic Contribution to NOx

“…Specifically, the highest concentrations occurred in November, December, and January, and the lowest values in June, July, and August (SI Figure S5; Table S3). Annually, the second study year exhibited higher values than the first, which is consistent with the worsening trend of pollution in South Asia …”

“…Annually, the second study year exhibited higher values than the first, which is consistent with the worsening trend of pollution in South Asia. 52 Pollutant concentrations are generally governed by meteorological conditions and emission sources. 53 The temperature and relative humidity shared an insignificant correlation with NO 3 − concentrations, indicating a weak impact of these meteorological parameters on the variation of NO 3 − .…”

In-Depth Analysis of Physicochemical Properties of Particulate Matter (PM10, PM2.5 and PM1) and Its Characterization through FTIR, XRD and SEM–EDX Techniques in the Foothills of the Hindu Kush Region of Northern Pakistan

“…Pakistani cities are facing serious air pollution-related problems; consequently, PM has significantly affected air quality in the region. Research regarding the chemical composition, size and morphology of PM is very limited in Pakistan, especially in small but rapidly growing cities [27][28][29][30][31]. PM has not been investigated in the urban environment of northern parts of Pakistan.…”

Spatiotemporal Investigations of Multi-Sensor Air Pollution Data over Bangladesh during COVID-19 Lockdown

“…In recent decades, rapid growth in urbanization and industrialization have affected the environmental health of Bangladesh. Previous studies have reported the air quality index (AQI) to be severely impacted by fine particulate matter from vehicular emissions and construction activities [8][9][10][11]. The AQI values on several occasions have exceeded the national ambient standards in Dhaka and Chittagong, which are ranked among the world's top ten most polluted cities during the dry season (i.e., November to April) [8,9].…”