Quantification and pollution profile of polycyclic aromatic hydrocarbons in coastal sediments of the south-central region of Bangladesh

Coastal ecosystems are increasingly threatened by polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants known for their carcinogenic and mutagenic effects. Bangladesh’s coastal regions are particularly vulnerable due to rapid industrialization, transportation, and tourism. However, limited research exists on PAH contamination in the sediments of these coastal regions. The motivation for this research arises from the potential health risks and ecological impacts associated with PAH accumulation, prompting an urgent need for effective pollution management strategies. This study aims to assess the levels, distribution, and sources of PAHs in the coastal sediment of three districts in Bangladesh using gas chromatography–mass spectrometry (GC–MS) and multivariate receptor models. Sixteen priority PAHs were analyzed, revealing a predominance of three to five ring structures. Source apportionment using Principal Component Analysis with Multiple Linear Regression (PCA-MLR), Positive Matrix Factorization (PMF), and the Unmix model identified coal combustion, traffic emissions, and biomass/wood burning as the primary contributors. PCA-MLR attributed 44.28%, 42.66%, and 13.07% to these sources, while PMF estimated 27.98%, 21.08%, and 38.85%, and the Unmix model assigned 24.91%, 25.23%, and 29.88%, respectively. Additionally, PMF and Unmix identified a mixed source contributing 12.09% and 24.9%, respectively. Our findings offer a comprehensive understanding of PAH contamination patterns in Bangladesh’s coastal sediments, identifying the critical sources of pollution and their relative contributions. The study underscores the urgent need for effective pollution control strategies to mitigate PAH accumulation and protect the ecological and socio-economic integrity of coastal regions.