[A-AS09] Atmospheric Chemistry

[AAS09-P11] Assessment of Heavy Elemental Origins and Health Risk of PM₁₀ at Urban Site of Varanasi situated over Central Indo Gangetic Plain (IGP) of India

*Preeti Tiwari^1,2, Bharat Ji Mehrotra³, Manoj K Srivastava³, Manoj Kumar^1,2, Narayanasamy Vijayan^1,2, Sudhir Kumar Sharma^1,2 (1. CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012, India., 2.Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India, 3.Department of Geophysics, Banaras Hindu University (BHU), Varanasi 221005, India)

Keywords:PM10, Elemental composition, Sources, Health risk assessment, Varanasi

In this study, we conducted a comprehensive analysis of trace/heavy elements concentrations, their sources and possible health risks associated with the inhalation of particulate matter (PM₁₀) in the city of Varanasi, situated over central Indo-Gangetic Plain (IGP) of India. Study is based on for the samples collected during Jan- Dec 2019. The PM₁₀ particulate matter samples were procured employing a high-volume RDS (respirable dust sampler) operating at a controlled environment of 1.12 m³ min⁻¹ flow rate (with a flow accuracy within ±2%) over a duration of 24 h. The assessment of element concentrations for 34 elements (Mg, Na, Al, Si, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr, Mo, Ag, Pm, Y, Rb, Pd, Fr, U, Pb, B, P, S, Cl, Br, Nb, Sr, F, As, and Ba) was conducted using WD-XRF technique. Predominant elements included Si, Al, S, Ca, K, Fe, Cl, and Mg, while Zn, Ba, Na, Ti, B, F, P, Ga, Ag, Zr, Mn, Cu, and Pd were present in trace amounts in PM₁₀ mass load (having annual average concentration as 228 ± 34 µg m⁻³). Principal Component Analysis (PCA) identified six factors contributing to elemental concentrations, namely crustal/soil/road dust, biomass burning, industrial emissions, agricultural activities, coal combustion, and vehicular emissions. Health risk assessments were performed to evaluate the potential health implications associated with heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni), utilizing non-carcinogenic and carcinogenic risk (CR) metrics. Elevated non-carcinogenic risks were identified for Al, Cr, and Mn, surpassing the established safe threshold of 1 for both adults and children. This signifies a non-carcinogenic adverse health impact and underscores the potential health risks associated with exposure to these specific heavy elements. Additionally, Cr exhibits a carcinogenic effect in adults, as its value surpass the safe threshold limit (1×10^-4) prescribed by the United States Environmental Protection Agency (USEPA). This study provides significant insights into the behaviour and risk mitigation strategies associated to heavy elements in the studied region.