Tissue-specific distribution of toxic metals and dietary risk indicators in commercial marine fish from the Chabahar coast, Oman Sea

The accuracy of seafood safety evaluations in industrializing coastal ecosystems has been constrained by the lack of integrated and tissue-specific assessments. This study addresses this gap by tailoring a comprehensive, multi-indicator evaluation of heavy metal, selenium–mercury interactions, and associated human health risks in three commercially important marine fish species from the Chabahar coast in the Oman Sea. A total of 36 specimens were analyzed across muscle, liver, and kidney tissues, accompanied by Se: Hg molar ratio, selenium health benefit value (HBV Se ), and advanced risk metrics. Results revealed a highly significant tissue-dependent accumulation pattern, with liver and kidney indicating higher metal concentrations than muscle. The highest concentrations were observed in C. chanos , including Hg (0.175 mg kg⁻¹) in the kidney and Se (6.11 mg kg⁻¹) and As (4.69 mg kg⁻¹) in the liver, whereas the highest muscle Hg concentration was detected in S. putnamae (0.046 mg kg⁻¹). Selenium consistently exceeded Hg, resulting in high Se: Hg molar ratios (30.4–470) and positive HBV Se values (≤ 77.4 µmol kg⁻¹), indicating a potential mitigating interaction between Se and Hg. Human health risk assessment illustrated low non-carcinogenic risk, and the cumulative hazard index (0.159–0.270) remained below the safety threshold. For As, the carcinogenic risk value for C. chanos exceeded the upper reference value of 10 − 4 , when the cancer slope factor for inorganic As was applied to the estimated inorganic-As fraction (10% of total-As concentration). This study provided an integrated framework linking metal interactions, bioaccumulation, and health risk indices, presenting applicable insights for improved seafood safety regulation.