Integrated assessment of polycyclic aromatic hydrocarbons (PAHs) in street dust of Behbahan, Iran: source apportionment, health risk and spatial distribution using GIS

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic pollutants widely found in urban environments, but data from small Middle Eastern cities are scarce. This study evaluates 16 priority PAHs in street dust from Behbahan, a semi-arid city in southwestern Iran influenced by traffic, fossil fuel combustion, and regional dust transport. Street dust samples from 20 sites were analyzed using GC–MS, showing total PAH concentrations of 131–2301 µg/kg, with higher levels near major roads and fuel-handling areas. Diagnostic ratios and principal component analysis indicated dominant pyrogenic sources related to vehicular emissions, with minor petrogenic inputs. Health risk assessment using the USEPA incremental lifetime cancer risk model showed that ingestion and dermal contact were the main exposure pathways. Children exhibited higher cancer risk than adults (mean ILCR = 5.54 × 10–5), although all values remained within acceptable limits. GIS-based spatial analysis identified localized PAH hotspots linked to traffic intensity, supporting targeted urban pollution management strategies.