Measurement / residue studyindependent cross-checkabstract only checked I-FSH-08 standard review
Metals in Egyptian farmed tilapia
Potential health risk assessment of some bioaccumulated metals in Nile tilapia (Oreochromis niloticus) cultured in Kafr El-Shaikh farms, Egypt.
Overview
Shaaban NA et al.. Environ Res 2021 · PMID 34043970 · DOI 10.1016/j.envres.2021.111358
Metal levels in muscle were judged safe, though fish tissues showed damage at drainage-water farms.
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?
Assess metals.
- How was the study done?
ICP-OES.
- How many people, animals or samples were studied?
200 fish.
- What was actually found?
Safe for consumers.
- What do the results mean in everyday life?
Farm water quality matters.
- What are the study's limitations?
Three farms.
- What does it say about Elawady's specific claim?
Contradicts general harm.
- Do the results apply to Germany and Europe?
Low.
- What can explicitly not be concluded from this study?
Mercury.
Scientific in-depth review
1. Full reference
- Authors
- Shaaban NA et al.
- Journal
- Environ Res
- Year
- 2021
- Identifier
- PMID 34043970 DOI 10.1016/j.envres.2021.111358
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- abstract only
- Conflicts of interest and funding
not stated in abstract/record
2. Research question
Metals in tilapia from farms using drainage water and consumer risk
3. Study design and population
- Study design
- Measurement / residue study – Metal measurement and health-risk assessment in farmed Nile tilapia
- Population
200 farmed tilapia from 3 farms
- Country
Egypt (Kafr El-Sheikh)
- Period
published 2021
- Sample size
200
4. Methods and endpoints
- Exposure / intervention
Farm (drainage water)
- Endpoints
Fe, Mn, Zn, Cu, Cr, Cd, Pb; histopathology; risk
- Statistical methods
ICP-OES
5. Actual results
- Results
Order Fe > Zn > Cu >= Cr > Mn > Pb > Cd; liver > muscle; histopathological changes in fish from drainage-irrigated farms; 'risk assessment indicated the safe human consumption'.
- Absolute risks
not reported
- Authors' conclusion
Safe human consumption of cultured fish from these farms.
6. Strengths
- n=200
7. Weaknesses
- No mercury
- Three farms
8. Risk of bias
- Orienting tool
- none applicable
- Type of assessment
- simplified assessment (abstract only)
- Full formal assessment
- no
- Overall risk of bias
- low
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
C-FSH-12, C-FSH-02 (contradicts general harm).
11. Independent contrary findings
12. Transferability to Germany and Europe
Low.
13. Overall methodological judgement
Reassuring for muscle; fish health affected.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | moderate |
| Risk of bias | low |
| Precision of results | moderate |
| Directness | direct |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | low |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
15. Linked fact checks
- Farmed fish (e.g. tilapia, mullet) are forbidden because their food is not clean: they are fed poultry manure and poultry offal, and the waste of fish farms is in turn fed to cattle. – Studies contradicting or limiting the claim