Polycyclic aromatic hydrocarbons (PAHs) in oysters (Saccostrea cucullata) and coastal sediments of the Oman Sea: Distribution patterns, sources, and health risk assessment.

Abstract

In this study, the concentrations, compositional patterns, sources, and human health risks of polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments and the oyster Saccostrea cucullata collected from five tidal beach stations along the Oman Sea. Total PAH concentrations in surface sediments ranged from 171 to 533 ng g-1 dw, whereas markedly higher levels were recorded in oyster tissues (1064-4219 ng g-1 dw), indicating substantial bioaccumulation. A significant positive correlation was observed between PAH concentrations in sediments and corresponding oyster tissues (p < 0.05), and both matrices exhibited similar compositional patterns, suggesting that sediment contamination directly influences PAH accumulation in oysters. Source diagnostic ratio analysis indicated a predominance of petrogenic sources, with low-molecular-weight PAHs being more abundant than high-molecular-weight compounds in both sediments and oysters. Although the EDI values were below the recommended threshold levels, the presence of PAHs in oysters reflects their bioavailability in the coastal environment and warrants continued monitoring. Given the bioaccumulation of PAHs in bivalves and the associated human health risks, long-term biomonitoring programs using bivalves are strongly recommended to support pollution mitigation efforts and ensure seafood safety.