EFSA 2015 - Fish/seafood benefits versus methylmercury risk
EFSA’s 2015 Scientific Committee statement turns the 2012 CONTAM methylmercury opinion and the 2014 NDA seafood-benefit opinion into population-specific fish/seafood scenarios. The useful point for the wiki is not a single fish-consumption recommendation: EFSA explicitly says Europe-wide advice is not possible because fish species, serving sizes, and national diets differ. Instead, it shows how quickly the methylmercury tolerable weekly intake can be reached when toddlers, children, pregnant-capable women, or high fish consumers rely on higher-mercury species. In the scenario tables, some groups reach the 1.3 ug/kg bw/week methylmercury TWI at less than or about one fish/seafood serving per week, many toddlers and children reach it at 2-3 servings/week, and high-mercury species such as swordfish, pike, tuna, hake, and cod/whiting drive the risk side of the balance.
Key numbers
Core toxicology and benefit reference values:
| Parameter | Value | Notes |
|---|---|---|
| EFSA methylmercury TWI used in the statement | 1.3 ug/kg bw/week | From EFSA CONTAM 2012, based on prenatal neurodevelopmental toxicity |
| Uncertainty factor embedded in TWI | 6.4 | For variability in extrapolating hair mercury to intake |
| Adult n-3 LCPUFA DRV used for scenarios | 250 mg/day EPA+DHA | Also used for older children and adolescents for practical scenario purposes |
| Toddler n-3 LCPUFA scenario intake | 125 mg/day EPA+DHA | Practical value used by the Scientific Committee |
| Women of child-bearing age n-3 LCPUFA scenario intake | 350 mg/day EPA+DHA | Practical value used to reflect pregnancy/lactation needs |
| Fish/seafood intake associated with reported benefits | 1-2 to 3-4 servings/week | Compared with no fish/seafood intake |
| Common European fish-advice serving assumption cited | 150-300 g/week | Usually 1-2 servings of about 150 g |
Methylmercury occurrence values used in the scenario tables:
| Fish/seafood item | MeHg occurrence (ug/kg) | n-3 LCPUFA (mg/100 g) |
|---|---|---|
| Swordfish | 1,212 | 3,015 |
| Pike | 394 | 229 |
| Lobster | 302 | 515 |
| Tuna | 290 | 2,806 |
| Bream | 225 | 467 |
| Bass | 202 | 467 |
| Lophiiformes | 195 | 261 |
| Redfish | 189 | 175 |
| Fish meat, composite category | 166 | 974 |
| Perch | 165 | 175 |
| Hake | 136 | 679 |
| Mackerel | 107 | 2,504 |
| Cod/whiting | 94 | 245 |
| Whitefish | 85 | 750 |
| Sole | 76 | 226 |
| Plaice | 64 | 403 |
| Carp | 55 | 296 |
| Squid | 46 | 350 |
| Fish products | 38 | 304 |
| Herring | 36 | 2,482 |
| Salmon/trout | 33 | 1,815 |
Selected scenario outputs from Appendix D:
| Country / population group | Servings/week to reach MeHg TWI | Servings/week to reach n-3 LCPUFA DRV | Interpretation |
|---|---|---|---|
| Italy, other children | 0.5 | 1.0 | MeHg TWI reached before one weekly serving in this scenario |
| Italy, adolescents | 0.7 | 0.7 | TWI and DRV reached at about the same intake |
| Italy, women of child-bearing age | 0.7 | 0.9 | High-mercury species mix makes MeHg limiting |
| Italy, adults | 0.8 | 0.6 | TWI reached below one serving/week; DRV reached slightly earlier |
| Spain, other children | 0.8 | 1.2 | MeHg TWI reached before DRV |
| Spain, women of child-bearing age, AESAN-FIAB | 1.3 | 1.3 | TWI and DRV reached together |
| Bulgaria, toddlers | 1.7 | 1.0 | TWI reached at 1.7 servings/week |
| Finland, toddlers | 1.7 | 4.3 | MeHg TWI reached far before DRV |
| Germany, toddlers 2006 | 2.0 | 2.7 | MeHg TWI reached before DRV |
| Belgium, other children | 2.2 | 2.7 | Example calculation in the statement |
| Finland, elderly | 2.7 | 3.1 | MeHg TWI reached before DRV |
| Czech Republic, adults | 4.1 | 1.2 | DRV reached well before MeHg TWI |
| Belgium, adults | 6.0 | 1.5 | DRV reached well before MeHg TWI |
| Spain, adolescents AESAN-FIAB | 6.6 | 2.9 | DRV reached well before MeHg TWI |
Dietary-exposure facts carried forward from the CONTAM opinion:
| Exposure fact | Value / finding |
|---|---|
| CONTAM occurrence dataset used by EFSA | About 60,000 mercury analytical results overall, about 22,000 for fish/seafood |
| MeHg assumption for fish meat, fish products, fish offal, and unspecified fish/seafood | 100% of total mercury as methylmercury |
| MeHg assumption for crustaceans, molluscs, and amphibians | 80% of total mercury as methylmercury |
| Mean middle-bound MeHg dietary exposure range across surveys | 0.06-1.57 ug/kg bw/week |
| P95 middle-bound MeHg dietary exposure range across surveys | 0.14-5.05 ug/kg bw/week |
| High/frequent fish-meat consumers, P95 consumers only | 0.54-7.48 ug/kg bw/week |
| Highest regular-exposure concern groups | Toddlers, other children, women of child-bearing age, and high fish consumers |
| Dominant food contributors | Fish meat first, then fish products |
| Main adult species contributors | Tuna, swordfish, cod/whiting, pike |
| Main child species contributors | Tuna, swordfish, cod/whiting, pike, and hake |
Methods (brief)
The Scientific Committee did not create a new occurrence dataset. It used the EFSA CONTAM 2012 mercury/methylmercury occurrence and exposure analysis, the EFSA NDA 2014 seafood-benefit analysis, and fish/seafood consumption data from the EFSA Comprehensive European Food Consumption Database. Only population groups with at least 20 individuals were used. Because many national surveys used short recalls or records that could overstate weekly high-end intake if simply multiplied by seven, EFSA built scenario servings for groups at risk of exceeding the TWI. Each scenario combined the main MeHg exposure contributors for that group, the reported serving sizes, the fish-item MeHg concentrations, and n-3 LCPUFA content values, then estimated how many weekly servings would reach the MeHg TWI and how many would reach the n-3 LCPUFA reference intake.
Implications
This source supports mercury and methylmercury routing for fish and seafood pages, especially where the wiki needs to explain why broad fish-advice claims need species-specific qualification. It reinforces that total fish consumption is not enough to classify methylmercury risk: a serving pattern dominated by swordfish, pike, tuna, hake, or cod/whiting can reach the MeHg TWI much sooner than one dominated by low-mercury, high-n-3 species such as salmon/trout or herring. The statement also supports a risk-benefit framing for toddlers, children, and pregnant-capable women: the nutritional benefit target can often be met by shifting species rather than increasing high-mercury fish.
Wiki pages this source may touch
- mercury
- fish
- seafood
- canned-tuna
- tinned-fish
- swordfish
- shellfish
- freshwater-fish
- fish-marine-predatory
- fish-marine-non-predatory
- fish-freshwater
- shellfish
- fresh-fish
- canned-fish
- canned-seafood
- efsa-methylmercury-twi
Verification notes
- Read the PDF text through the appendices, including Appendix C occurrence values, Appendix D servings-to-TWI/DRV table, and Appendix E exposure/contributor tables.
- DOI verified from the PDF citation and metadata as
10.2903/j.efsa.2015.3982. - This source should not be used as a new primary occurrence survey. It is a risk-benefit scenario statement built on EFSA CONTAM 2012 occurrence/exposure data and EFSA NDA 2014 benefit evidence.
- The statement uses total-mercury-to-methylmercury assumptions from the CONTAM opinion: 100% MeHg for fish meat/products/offal/unspecified fish and 80% MeHg for crustaceans and molluscs. Keep that assumption visible if extracting routeable values from this source.
- EFSA notes several uncertainties: short dietary recalls can inflate high-end weekly intake, some fish categories were poorly characterized, several serving-size estimates had few eating events, and redfish/Norway-lobster n-3 values required proxy assumptions.
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.