Comprehensive Analysis of PM1 Composition in the Eastern Indo-Gangetic Basin: A Three-Year Urban Study

Abstract

Particulate matter (PM) pollution poses a severe threat to the environment and health worldwide. This study aimed to evaluate the mass concentration, physicochemical characteristics, and emission sources of aerodynamic diameters of ≤1 µm (PM1) within an urban sprawl situated in the eastern Indo-Gangetic basin over three years (2017–2019). The study encompassed the monitoring of PM1 using an ambient PM1 sampler; physicochemical characteristics were determined through scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and inductively coupled plasma-optical emission spectrometry (ICP-OES). Possible emission sources were analysed through principal component analysis (PCA) and enrichment factor (EF) analyses. The results showed that the PM1 concentrations were consistently high throughout the research period, even exceeding the national standards for PM2.5 and PM10, especially during the post-monsoon period. Significant seasonal fluctuations were confirmed by the elemental and inorganic ion analyses, highlighting the dominance of elements like Al, Ca, Fe, K, and Mg and inorganic ions like NH4+, SO42−, and NO3−. Vehicular exhaust and non-exhaust (47%), sea salt and biomass burning (26%), and industrial activities (10.3%) are the dominant sources of PM1. Therefore, the findings are thought-provoking and could inspire policymakers to formulate reduction policies in India.