P09-37 Mercury in Sphyrna lewini: Evaluating Consumption Risks Across Different Population Groups

Consumption of elasmobranch meat poses significant risks of exposure to environmental contaminants, particularly metals and metalloids, which are prevalent pollutants in marine ecosystems. Among these, mercury (Hg) is of particular concern due to its high toxicity and potential to cause severe health effects in living beings. Hg bioaccumulates in aquatic organisms and biomagnifies through the food chain, with concentrations increasing according to the size, age, and feeding habits of the animals. Brazil is the world's largest importer and one of the main consumers of elasmobranch meat. Among these species, Sphyrna lewini is frequently caught by fishing fleets and is highly vulnerable to anthropogenic pressures. This study aimed to assess Hg contamination in S. lewini muscle tissue and evaluate the health risks associated with its consumption. Sharks were sampled from fishing landings in Matinhos, Paraná, Brazil, with 30 specimens analyzed. Hg concentrations were measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and method accuracy was confirmed through reference material recovery. To assess consumption risks, the hazard quotient (HQ) was calculated, representing the probability of a substance causing non-carcinogenic adverse effects over a lifetime. Hg concentrations in S. lewini muscle ranged from 0.03 to 0.25 μg g⁻¹ wet weight (mean±SD: 0.10±0.05 μg g⁻¹), which are notably lower than those reported in other regions, such as Mexico (0.63±0.04 μg g⁻¹) and Oceania (1.21 μg g⁻¹). This suggests of S. lewini from Paraná may experience lower environmental exposure to Hg contamination. However, the exclusive sampling of juveniles may have influenced these results. Health risk assessments showed that HQ values remained below 1 for the general population (0.87 for children, 0.35 for adolescents, 0.23 for women, and 0.20 for men), indicating minimal risk. However, values for children were close to the safety threshold. In contrast, HQ values exceeded safe limits in traditional fishing communities, with values of 4.37 for children, 1.74 for adolescents, 1.16 for women, and 0.99 for men, highlighting significant long-term health risks. These communities are particularly vulnerable due to their reliance on fish as a dietary staple, leading to increased Hg exposure. This study provides critical insights into Hg contamination in S. lewini from Paraná, revealing relatively low Hg levels compared to other regions. While health risks appear minimal for the general population, concerns persist traditional fishing communities. Although Hg levels may not pose immediate health hazards, the frequent capture of juveniles of these species emphasize the urgent need for stricter conservation measures and consumer awareness to ensure sustainability.