Polyaromatic hydrocarbons and trace metals in road-deposited soil, source apportionment, and risk analysis: evidence from the largest port city of Bangladesh
摘要
This study assessed the concentration of 6 trace metals (Pb, Cd, Cr, Cu, Ni, and Fe) and 16 USEPA priority polyaromatic hydrocarbons (PAHs) in road-deposited soil in Chattogram, the largest port city of Bangladesh. The soil texture analysis conducted during this study revealed the presence of several soil types with variable quartz content. The basic nature and high electrical conductivity (EC) indicate high amount of dust deposition by the moving traffic, while low content of organic carbon indicate regular road construction can be prevalent in the studied area. The physicochemical characteristics did not affect the trace metal and PAH accumulation pattern. Among the metals studied, Pb pollution was observed to be moderate to high, whereas potential toxicity of PAHs' was significant. Both Chronic Daily Dose (CDD) and Hazard Quotient (HQ) values were higher for Fe especially in children associated with ingestion. Children's total cancer risk (TCR) was low from trace metals and also there was no significant health risk linked to PAHs for either adults or children. Petroleum was shown to be the primary source of PAHs using the Molecular Diagnostic Ratios (MDRs). Principal Component Analysis (PCA) highlighted several overlapping sources of trace metals and PAHs, including traffic emissions, industrial activities, and pyrogenic processes, indicating significant anthropogenic impacts. These findings underscore the necessity for pollution control actions to mitigate health and environmental vulnerabilities along the major roads.