Cegolon et al. 2022 — Mercury in human hair linked to fish and shellfish consumption, Gulf of Trieste
This cross-sectional biomonitoring study measured total mercury (tHg) in scalp hair of 301 residents of the Gulf of Trieste coastal area in Italy, a region historically contaminated by mercury from the Idrija cinnabar mining district (Slovenia) via the Isonzo/Soča river system. The mean hair Hg concentration was 1.63 mg/kg, slightly above the 1.0 mg/kg WHO reference for pregnant women and children, though well below the NOAEL of 10 mg/kg. Shellfish/crayfish/mollusk preference was the strongest positive predictor of elevated hair Hg (adjusted RC = 0.35; 95% CI: 0.16, 0.55), and preference for frozen fish was protective (adjusted RC = -0.23), consistent with the dominance of MeHg from aquatic food chain exposure.
Key numbers
- Mean hair Hg: 1.63 ± 1.50 mg/kg; median 1.2 mg/kg (IQR: 0.78, 1.86)
- Male mean: 1.85 ± 1.79 mg/kg; female mean: 1.48 ± 1.23 mg/kg
- 55.6% of participants had hair Hg > 1.0 mg/kg (WHO threshold for pregnant women/children)
- 22.9% had hair Hg > 2.0 mg/kg
- 2 participants (0.7%) had hair Hg > 10 mg/kg (NOAEL)
- LOD: 0.004 mg/kg by Direct Mercury Analyzer DMA-80 (EPA Method 7473)
- CRM recovery 98–106%
- n = 301; recruited September 2021
Methods (brief)
Hair samples (~100 mg) from occipital scalp; analyzed by Direct Mercury Analyzer (DMA-80, Milestone) per EPA Method 7473. Total Hg measured (no speciation to MeHg vs inorganic Hg). Questionnaire on diet including fish consumption frequency and type. Multiple linear regression on log-transformed hair Hg. LOD = 0.004 mg/kg.
Implications
Certification: Demonstrates shellfish and small/medium fish consumption as primary MeHg exposure pathway for coastal populations; relevant to seafood product risk framing. Courses: Strong example of dietary biomonitoring establishing fish-type specificity of MeHg exposure. App: Supports MeHg risk elevation for shellfish and mixed-fish dietary patterns.