Relationship between shark meat intake and blood mercury concentration in Korean adolescents

Mercury exposure through seafood consumption poses health risks, yet limited research has examined shark meat-a large predatory fish still consumed in Korea-and its association with blood mercury levels in adolescents.

This cross-sectional study used data from the 3rd Korean National Environmental Health Survey (KNEHS). Multiple linear and logistic regression analyses were performed to assess the association between shark meat intake and blood mercury levels and to estimate the odds ratios for exceeding the reference blood mercury level, adjusting for potential confounders.

Of the 912 participants, 50 (5.5%) were identified as shark meat consumption group. Shark meat consumption was associated with higher blood mercury concentrations (β = 0.41; 95% confidence interval [CI]: 0.23-0.59), with the highest levels observed among those who consumed shark meat within the past 30 days (β = 1.19; 95% CI: 0.30-2.08), those who preferred shark meat (β = 0.67; 95% CI: 0.26-1.08), and those with higher annual intake (β = 0.71; 95% CI: 0.00-1.43). Shark meat consumers had substantially higher odds of exceeding the blood mercury reference level (≥5.8 μg/L; odds ratio: 35.84; 95% CI: 3.39-378.84), with an estimated attributable risk of 97.2% (95% CI: 70.5%-99.7%) and a population attributable risk of 65.7% (95% CI: 11.6%-95.4%). Of the estimated 25,740 (95% range: 11,905-54,913) adolescents aged 12-17 years potentially exceeding this threshold, approximately 16,911 (95% CI: 2,986-24,556) cases may be attributable to shark meat consumption, though these estimates should be interpreted cautiously given the wide confidence intervals.

Shark meat consumption was associated with elevated blood mercury levels in Korean adolescents. Targeted education on its potential health risks is needed to reduce unintended exposure, while maintaining the nutritional benefits of fish consumption.