Spatial variation of potentially toxic elements in commercially important fish from the Saudi Red Sea and implications for dietary health-risk assessment

Potentially toxic elements (PTEs) in marine fish represent an important human exposure pathway in coastal communities. This study quantified eleven PTEs—arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), vanadium (V), manganese (Mn), and zinc (Zn)—in muscle and gill tissues of 461 fish representing three commercially important taxa ( S. longiceps , Herklotsichthys spp., and Carangoides spp.) collected from four Saudi Red Sea locations: Umluj, Yanbu, Al-Qunfudah, and Jazan. Concentrations were determined by ICP-MS with certified reference material validation. Concentrations varied substantially among locations and tissues, with the most pronounced spatial differences for As and V. Jazan consistently showed the highest As and V concentrations across all taxa; mean total As in Jazan S. longiceps muscle (1.064 mg/kg wet weight) exceeded the FAO/WHO guideline of 1.0 mg/kg, while V concentrations were approximately 40-fold higher than at northern locations. Hg and Pb were below detection limits in all muscle samples. Dietary exposure was evaluated using estimated daily intake, target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR). Under baseline consumption (7 g/day), non-carcinogenic risk remained below unity (HI < 1.0) at all locations. However, under higher-consumption scenarios (50 g/day), HI exceeded unity at Jazan (1.16), and TR for inorganic arsenic exceeded the USEPA acceptable upper bound (1 × 10⁻⁴) at Jazan and Al-Qunfudah even at baseline consumption. The findings identify Jazan and Al-Qunfudah as priorities for continued seafood monitoring and risk communication, particularly for high-consumption populations and children. Because arsenic speciation was not directly measured, inorganic arsenic was estimated from total As (7% of total As, EFSA 2009), and risk estimates are therefore scenario-based rather than definitive measurements of inorganic arsenic exposure.