Determinants of human hair mercury, blood mercury, blood selenium, and plasma omega-3 fatty acid levels within northern Canada.
Level 4 - case-series / case-control
Cross-sectional biomonitoring study (Level 4 by study design)
PubMed 41183436 · doi:10.1016/j.ijheh.2025.114703
What was done
Human biomonitoring projects across the Dehcho and Sahtú regions (Northwest Territories) and Old Crow (Yukon) analyzed hair and blood total mercury, blood selenium, and plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Researchers evaluated demographic and dietary determinants using Spearman correlations, geometric mean comparisons across participant strata, and multivariable regression models.
What was found
Participant age and consumption of at least one species of fish and waterfowl were associated with mercury (adjusted R² = 0.26 for hair mercury) and EPA + DHA (adjusted R² = 0.33) biomarker concentrations. Region and consumption of several fish species and caribou livers/kidneys were associated with blood selenium (adjusted R² = 0.32). Mercury and EPA + DHA biomarker levels correlated moderately to strongly across all three regions (rₛ = 0.36 to 0.65), while correlations with selenium were inconsistent (rₛ = 0.04 to 0.28).
Why it matters
These findings show that traditional food consumption simultaneously drives exposure to environmental mercury and intake of essential nutrients (omega-3 fatty acids and selenium), highlighting the need to balance nutritional benefits against contaminant risks.
Limits
The total sample size (n) is not reported in the abstract. The cross-sectional design cannot establish causality, and dietary data were based on self-reported consumption patterns.
Cited by
- supports Consuming higher amounts of dietary omega-3 sources typically increases mercury levels because most omega-3 sources contain mercury.