Investigation of the accumulation and sources of polycyclic aromatic hydrocarbons (PAHs) and mercury (Hg) in marine fish from the northern Bay of Bengal using a multi-tool approach.

This study investigated Polycyclic Aromatic Hydrocarbons (PAHs) and total Mercury (Hg) in commonly consumed seafoods from the northern Bay of Bengal. The PAHs were analyzed using GC-MS, and a Direct Mercury Analyzer was employed for total Hg. The results showed that total PAHs concentration ranged between 78.68 and 1000.33 ng/g (ww) and 3-ring and 4-ring PAHs dominated (>85 %). On the other hand, total Hg concentration ranged between 3.88 ± 1.71 to 67.69 ± 1.34 ng/g. The results highlighted a complex interplay between the feeding zone and habit to influence the contaminant accumulation pattern in marine fish. Among the studied species, pelagic fish demonstrated higher PAHs accumulation. However, Hg accumulation was higher in benthopelagic an demersal fish. In this study, the risk from non-cancer-causing PAHs remained <1, while the cancer threat associated with carcinogenic PAHs and Hg was negligible. Monte Carlo simulation on source-specific total cancer risk also demonstrated similar output by exhibiting very low simulated cancer risk with very low frequency and probability. The source apportionment analysis, conducted using Hierarchical Cluster Analysis and a Pearson Correlation Matrix, coupled with two receptor modeling approaches (PMF and Unmix), indicated that mixed combustion, petroleum pollution, and industrial activities were the primary contributors to the introduction of PAHs and Hg into marine fish. This investigation highlights the importance of source-specific control measures in mitigating marine pollution and protecting public health. Overall, this study underscores the importance of integrating bio-monitoring with ecological and receptor model-based approaches to form public health protection and marine environmental management.