A report released Tuesday by the NGOs Bloom and Foodwatch reveals that canned tuna is widely contaminated with mercury, a substance harmful to health. The organizations are urging retailers and public authorities to “take urgent measures,” including reducing the permitted limits.
The investigation conducted by Bloom involved randomly selecting 148 cans from five European countries—France, Germany, England, Spain, and Italy—and submitting them for testing at an independent laboratory. Alarmingly, 100% of the samples tested positive for mercury contamination.
According to the environmental advocacy group, more than half of the samples exhibited mercury levels exceeding the maximum limit set for other fish species, which is 0.3 mg/kg.
“The current maximum mercury levels for tuna in Europe have been determined based on observed contamination rates rather than the potential health risks posed by mercury. This approach primarily aims to facilitate the sale of 95% of the tuna available in the market,” the report emphasizes.
The established limits permit a maximum of 1 mg/kg of mercury in “fresh weight,” not accounting for the final product in the can. “This discrepancy allows tuna, one of the most contaminated species, to have a maximum mercury tolerance three times higher than that of the least contaminated species.”
The two NGOs argue that “there is no health justification for this discrepancy; mercury does not become less toxic when ingested through tuna. What matters is the concentration of mercury in food.”
Mercury, particularly from atmospheric deposits originating from coal-fired power plants, is classified by the World Health Organization (WHO) as one of the ten substances of greatest concern to public health.
In marine environments, mercury combines with bacteria and transforms into methylmercury, an even more toxic derivative.
“Elemental mercury and methylmercury are hazardous to the nervous system. Neurological and behavioral disorders can result from exposure,” the WHO states.
The organizations are calling on the European Commission to adopt the strictest maximum level it has established for other species, which is 0.3 mg/kg.
