Prenatal mercury exposure in a multicenter cohort study in Spain.
Level 3 - non-randomized controlled study
Prospective multicenter cohort study evaluating dietary exposure and cord blood biomarker levels
PubMed 21239061 · doi:10.1016/j.envint.2010.12.004
What was done
Total mercury (T-Hg) concentrations were measured in whole umbilical cord blood from 1,883 mother-child pairs recruited across a population-based multicenter cohort in Spain between 2004 and 2008. Maternal seafood consumption during pregnancy was assessed using a food-frequency questionnaire. Linear regression and mixed-effects linear models were used to evaluate associations between seafood intake subtypes, maternal characteristics, and cord blood T-Hg levels.
What was found
Mean maternal seafood consumption was 78 g/day, and the geometric mean cord blood T-Hg concentration was 8.2 µg/L. A doubling of maternal large oily fish intake was associated with an 11.4% increase (95% CI: 3.8% to 19.6%) in cord blood T-Hg. Doubling canned tuna consumption was associated with an 8.4% increase (95% CI: 5.7% to 11.2%), and doubling lean fish consumption with an 8.3% increase (95% CI: 5.5% to 11.1%). Maternal age, country of origin, education, employment, parity, geographic study area, and season of delivery were also associated with cord blood T-Hg.
Why it matters
This study demonstrates that prenatal mercury exposure in this Mediterranean cohort frequently exceeded the US EPA reference benchmark (5.8 µg/L), identifying specific seafood types—primarily large oily fish—as major modifiable exposure sources during pregnancy.
Limits
Seafood intake was self-reported via food-frequency questionnaires, introducing potential recall error. Total mercury rather than methylmercury was measured in cord blood. The abstract does not report clinical or neurodevelopmental outcomes in the infants.
Cited by
- supports High consumption of tuna can lead to elevated levels of mercury in the blood.