The tastiest is not always the safest: mercury risks of boneless fish consumption compared to other seafood traded in southeastern Brazil.

Seafood plays a crucial role in the food supply, but it is also a source of contaminants, such as mercury. The ubiquity, high toxicity, and biomagnification of mercury justify its monitoring in seafood as a priority for achieving the 2030 food safety goals. This study aimed to determine the total mercury (THg) and methylmercury (MeHg) contamination in eight seafood species commercially available in a metropolitan region of southeastern Brazil, thereby generating the Estimated Daily Intake (EDI) and the Hazard Quotient (HQ). The lowest THg concentrations were found in pangas and mussels (0.0003 ± 0.0003 and 0.0005 ± 0.0002 mg.kg-1 w.w., respectively), while the highest were found in blue sharks (1.27 ± 0.46 mg kg-1, w.w.). The blue shark was the only species with THg concentrations above the limit of 0.5 mg kg-1 for fish set by the WHO and the most toxic form of mercury, MeHg, predominated in 80 % of them. The blue shark HQ ranged from 0.91 to 2.97 and from 2.06 to 6.71 for Hg and MeHg. Therefore, the consumption of this specific group of seafood should be restricted or preferably avoided. Further studies should enhance the information on fish consumption among vulnerable and more exposed populations to obtain more reliable health risk assessments.