Systematic reviewindependent cross-checkabstract checked★ key study I-FSH-105 in-depth review
Mercury from seafood in women and babies worldwide
Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review.
Overview
Sheehan MC et al.. Bull World Health Organ 2014 · PMID 24700993 · DOI 10.2471/BLT.12.116152
High fish eaters in all regions studied had mercury intakes above the FAO/WHO reference; Mediterranean averages approached it.
Does the study support the specific claim? No · Methodological quality: moderate
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Map MeHg exposure.
- How was the study done?
Systematic review of 164 biomarker studies.
- How many people, animals or samples were studied?
Women and infants, 43 countries.
- What was actually found?
High-end consumers exceed the reference.
- How large was the observed effect?
Not expressed as risk.
- What do the results mean in everyday life?
Eating a lot of high-mercury fish raises exposure.
- What are the study's limitations?
No health outcomes.
- What does it say about Elawady's specific claim?
Wild sea fish carries mercury.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Harm at average intakes.
Scientific in-depth review
1. Full reference
- Authors
- Sheehan MC et al.
- Journal
- Bull World Health Organ
- Year
- 2014
- Identifier
- PMID 24700993 DOI 10.2471/BLT.12.116152
- Verification
- verified – PubMed efetch 2026-10-26; Crossref checked
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract
2. Research question
How does methylmercury intake in women and infants compare with the FAO/WHO reference level?
3. Study design and population
- Study design
- Systematic review – Systematic review of hair and blood mercury biomarkers
- Population
Women and infants in seafood-consuming populations
- Country
43 countries
- Period
Published literature to about 2012
- Sample size
164 studies
- Inclusion and exclusion criteria
Studies reporting total Hg in hair or blood
4. Methods and endpoints
- Exposure / intervention
Seafood methylmercury
- Comparator
FAO/WHO reference level
- Endpoints
Biomarker-based MeHg intake
- Statistical methods
Pooled medians by consumption context
5. Actual results
- Results
Intake several times over the reference near small-scale gold mining and well over it in Arctic marine-mammal consumers; 'In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference.' 'High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value.'
- Absolute risks
not reported
- Authors' conclusion
Policies to reduce mercury exposure among women and infants are needed.
6. Strengths
- Global, biomarker-based
7. Weaknesses
- Heterogeneous studies; pooled medians; no health outcome data
8. Risk of bias
- Orienting tool
- ROBIS
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Abstract only.
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
C-FSH-14: high fish consumers, including in Mediterranean coastal regions, approach or exceed the MeHg reference.
11. Independent contrary findings
12. Transferability to Germany and Europe
Moderate (Mediterranean).
13. Overall methodological judgement
Shows that high consumers of seafood can exceed MeHg reference values.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | some concerns |
| Precision of results | low |
| Directness | indirect |
| Reproducibility | unknown |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |