Polycyclic aromatic hydrocarbons in street dust of Babylon City, Iraq: identification, quantification, and possible sources

Abstract

Polycyclic aromatic hydrocarbon compounds (PAHs) are stable organic isomers known for their carcinogenic, mutagenic, and teratogenic effects, making monitoring and quantifying their presence in the environment critically important. This study aimed to identify, quantify, and determine the origin of PAH compounds in street dust samples collected from Babylon City, Iraq in 2023. A total of 39 street dust samples were collected from 13 selected locations with three replicates. The analytes were extracted using the Soxhlet method, followed by identification and quantification using gas chromatography with mass spectrometry (GC-MS). Ten PAH compounds were identified in the dust samples, with a mean concentration of 19.5 mg/kg. The total concentration ranged from 4.19 to 123 mg/kg. Low molecular weight isomers accounted for 86.2% of the total PAH content. The mean levels of phenanthrene (PHE), fluoranthene (FULA), and pyrene (PYR) isomers were below the maximum levels set by the Dutch Ministry of Health, while other isomers did not statistically differ from the permissible limit. Dust pollution with PAHs was very high at 7 locations (>50.00 mg/kg) and high at the remaining 6 locations. Strong positive correlations were observed among all isomers at a significance level of 99%, and multivariate data analysis indicated pyrogenic sources as the origin of PAHs in the dust samples. Results suggest that gasoline combustion and mixed combustion are the primary sources of PAH dust pollution in the study area. Therefore, regular monitoring of PAH levels is recommended to mitigate associated risks in Babylon City, Iraq.