Road dust emission assessment and elemental characterization in a non-attainment city: a case study of Ujjain, Madhya Pradesh, India

Abstract

Road dust resuspension represents a significant yet inadequately quantified contributor to urban particulate matter (PM) pollution in Indian non-attainment cities. This study aims to quantify road dust emissions and characterize the elemental composition of road dust in Ujjain, Madhya Pradesh—a city designated as non-attainment under India’s National Clean Air Programme (NCAP), through systematic field measurements, traffic surveys, and chemical characterization. During October 2023, road dust samples were collected at 11 strategically chosen sites that represent a variety of traffic densities with the help of the U.S. EPA-standardized protocols. The silt loading values showed that there was significant spatial heterogeneity of 4.3 g/m2 at Malkhamba Statue and 15.2 g/m2 at Piplinaka Chauraha with a city average of 8.4 ± 3.6 g/m2 (coefficient of variation (CV) = 43%). Extensive traffic surveys were recorded in terms of vehicle make-up in five categories with daily traffic volumes of 15,800 to 57,655 vehicles. The bcity-wide estimates of 132.37 tons/day PM10 and 32.03 tons/day PM2.5 were found by the use of the U.S. EPA AP-42 emission methodology. Ujjain Ring Road was the largest emitter of the total measured emissions 41.34 tons/day PM10. Wavelength dispersive X-ray fluorescence (WD-XRF) analysis revealed a dual-source structure: predominant crustal elements (Fe: 19.21%, Si: 14.2%) from soil and agricultural dust and traffic-related heavy metals (Zn, Cu, Ni, Cr, V) from non-exhaust vehicle emissions. Three high-emission hotspots Ujjain Ring Road, Aagar Naka, and Hari Fatak collectively account for 59.7% of the collected city-wide road dust emissions, underscoring the importance of spatially targeted mitigation strategies for air quality management in non-attainment cities. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2026.