Trace element residues in farmed Beluga sturgeon (Huso huso) from the Iranian markets: Human health risk assessment

Beluga sturgeon (Huso huso) is a commercially valuable species, but its long lifespan and high trophic level make it susceptible to bioaccumulation of trace elements. Thirty-six samples were analyzed by atomic absorption spectrophotometry and we quantified arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), nickel (Ni), zinc (Zn), and lead (Pb) in edible muscle of H. huso obtained from fish markets in Tehran, Gilan, and Mazandaran provinces, Iran. Inorganic arsenic (iAs) and methylmercury (CH3Hg), the toxicologically relevant species, were not directly measured but were estimated from total As and Hg concentrations using literature-based conversion factors for fish muscle. Human health risks were assessed using Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Lifetime Carcinogenic Risk (LCR) based on US EPA guidelines. Tehran samples showed the highest levels of Ni, Pb, CH3Hg, Zn, and Cu, while Cd was highest in Tehran and Gilan, and iAs peaked in Gilan. All EDI values were below international safety limits, and most THQ values were < 1, although one Tehran sample exceeded THQ = 1. LCR values for iAs surpassed the 1.0E-04 threshold for bladder and lung cancer, indicating notable lifetime carcinogenic risk. Despite its nutritional value, H. huso may pose health concerns in certain regions due to trace element contamination. Findings highlight the need for continuous monitoring of aquaculture inputs and risk-informed management strategies to ensure consumer safety and sustainable sturgeon production.