Mercury contamination has been found in cans of tuna tested across Europe, with some samples containing four times the permitted level, two NGOs warned on Tuesday. The highest level was found in cans sold by French brand Petit Navire.
Tests carried out by NGOs Bloom and Foodwatch showed all 148 cans tested positive for mercury contamination. The samples were bought in France, Germany, England, Spain and Italy.
Mercury is "one of the 10 substances of greatest concern in the world, like asbestos or arsenic," said the organisations. Its derivative, methylmercury, is classified as a "possible carcinogen" by the International Agency for Research on Cancer (IARC).
More than half the tested cans contained mercury levels higher than those permitted for other fish species.
While mercury content in fish like pollack or cod must not exceed 0.3 mg/kg, the limit for tuna is set at 1 mg/kg.
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'Most eaten' fish in Europe
The NGOs criticised this discrepancy and called for authorities to impose the lower 0.3 mg/kg limit on tuna – Europe's most consumed fish.
According the groups, tuna remains the most consumed fish in Europe.
"This metal is a powerful neurotoxicant and low doses consumed regularly are enough to cause serious disorders of the nervous system in children and attack the brain functioning of adults," said the NGOs.
The highest concentration was found in French brand Petit Navire at 3.9 mg/kg. Spain's Carrefour products followed with 2.5 mg/kg, while Italian brand As do Mar showed levels up to 1.5 mg/kg.
Bloom and Foodwatch demanded authorities stop the sale of tuna products exceeding 0.3 mg/kg of mercury. They also called for bans in nurseries, hospitals, maternity wards, retirement homes and school canteens.
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Petition
The NGOs launched a petition urging retailers to implement stricter controls, stop promoting tuna and inform consumers about health risks.
France's food safety agency Anses backed these concerns last Thursday, warning that "at high doses, methylmercury is toxic to the central nervous system of humans, particularly during in utero development and early childhood".
The agency advised eating fish no more than twice weekly and limiting "predatory fish" like tuna. It specifically warned pregnant women to avoid predatory fish including tuna, skate, sea bream and monkfish, which are known to be most contaminated.