Mercury in imported fish and shellfish, UK farmed fish and their products (40/03)
Thursday 24 July 2003
The Food Standards Agency has conducted a survey of mercury in a wide range of imported fish and shellfish and their products, including canned and smoked fish, seafood sticks, spreads and pastes.
Mercury is widely present in the environment from both natural and man-made sources and can accumulate in the food chain, particularly in fish. In the UK, fish is the main source of mercury in the diet. The aim of this survey was to provide data on fish and shellfish on which we previously had limited or no information, and to allow a more accurate and detailed estimate of dietary intakes of mercury by consumers of these products.
The results of this survey provided the basis of the Agency’s precautionary advice to consumers. Interim precautionary advice on eating shark, swordfish and marlin was issued in May 2002, and following an extensive review by the independent Committee of Toxicity, additional advice to restrict tuna consumption for high risk groups of the population was issued in February 2003.
Key facts
- Total mercury concentrations were measured in 336 samples of imported fish and shellfish, UK farmed fish and their products.
- Levels in most fish and shellfish were relatively low as found in a previous survey of the most commonly consumed marine fish in the UK. Levels of mercury in the larger predatory species, shark, swordfish and marlin were higher, and in some samples of these species, exceeded the relevant EU-wide regulatory limit for mercury.
- Dietary exposures to mercury were estimated for consumers of fish and shellfish for all age groups of the population. Exposure estimates for some consumers were close to or exceeded the WHO safety guideline, which WHO had noted was not sufficiently protective for pregnant women. The FSA therefore issued precautionary advice on the consumption of fish with the highest concentrations of mercury (shark, swordfish and marlin), and requested an opinion on the risks from the independent Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT).
- The independent Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) carried out an extensive review of the possible risks for consumers of fish, and recommended that a lower safety guideline should be used in considering consumption by pregnant women, or women who may become pregnant in the next year, and breast feeding women, because of the risk to the unborn or new born baby.
- As a result of the findings of this survey and the review by the COT, the Agency issued precautionary advice that:
- Pregnant and breast-feeding women, and women who intend to become pregnant, should limit their consumption of tuna to no more than two medium size cans or one fresh tuna steak per week;
- These women are also advised to avoid eating shark, swordfish and marlin;
- Children under 16 are also advised to avoid eating shark, swordfish and marlin;
- Other consumers should eat no more than one portion of shark, swordfish or marlin per week, but do not need to limit consumption of tuna.
Related links
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