Geographical Analysis of the Concentration of Heavy Elements Resulting from Urban Transport in Al-Diwaniyah City

Abstract

This study investigates the spatial distribution and seasonal variations of suspended lead (Pb) and cadmium (Cd) concentrations in the ambient air of Diwaniyah City in 2025, serving as a case study for pollution associated with urban transport and combined anthropogenic activities. Meteorological and environmental parameters were measured at 14 georeferenced sampling stations across the city's urban sectors during winter and summer. The findings revealed significant spatial and temporal fluctuations; lead concentrations were systematically higher in summer than in winter across all stations, peaking in summer at 14.2778\mu\g/m3 at Al-Nisour intersection (S7) and reaching its lowest winter value of 0.6024\mu\g/m3 at Al-Maayaria (S14). Cadmium concentrations reached their winter maximum of 3.0668 \mu\g/m3 in Al-Forat neighborhood (S4) and a minimum of 0.3081 \mu\g/m3 at the City Entrance (S1), while summer cadmium concentrations peaked at 4.2569 \mu\g/m3 at Taiba Mall (S5) with a minimum of 0.9028 \mu\g/m3 at Al-Ulama square (S9). When benchmarked against regulatory criteria, summer lead levels heavily violated Iraqi National Ambient Air Quality Standards at most sites, whereas cadmium levels in both seasons critically exceeded the World Health Organization (WHO) health-based guidelines by several hundred folds, indicating high cumulative toxicological and carcinogenic risks to the urban population.