Dangerous mercury levels found in European canned tuna

Canned tuna sold across major European supermarkets has been found to be 100% contaminated with mercury, according to a recent report by NGOs Bloom and Foodwatch. On October 29, 2023, Bloom unveiled a report revealing dangerously high concentrations of mercury in canned tuna from five European countries: France, Germany, Britain, Spain, and Italy. The NGOs analyzed nearly 150 cans of tuna purchased from supermarkets across these countries, sending them to independent laboratories for analysis.

Laboratory analysis revealed that all of the 148 tins of tuna tested were contaminated with methylmercury, a particularly dangerous form of mercury that accumulates in fish and poses serious health risks to humans. The analysis showed that 57% of the cans exceeded the strictest maximum mercury limit defined for fish in the European Union, which is 0.3 mg/kg. More alarmingly, 10% of the cans surpassed the authorized limit for fresh tuna, set at 1 mg/kg in Europe. One can, from the brand Petit Navire, purchased in a Carrefour City in Paris, reached a record concentration of 3.9 mg/kg, 13 times higher than the stricter limit.

Bloom and Foodwatch described the situation as a "genuine public health scandal," demanding "urgent measures" from European and national authorities, including lowering the allowed limits of mercury. They are urging government regulators and supermarket chains to take immediate action to protect consumers, particularly vulnerable populations such as fetuses and young children. According to the NGOs, there is no health-based justification for the discrepancy in mercury limits between tuna and other fish species. Currently, the maximum permitted level of mercury for tuna in the EU is set at 1 mg/kg, more than three times higher than that of other fish species, where the limit is 0.3 mg/kg.

Mercury is a heavy metal resulting from coal combustion, mining, and certain industrial activities. The World Health Organization (WHO) classifies mercury among the ten substances most concerning for public health and considers it one of the most dangerous toxic chemicals for human health. Mercury is "a potent neurotoxin" that can cause serious problems in neuronal development in children and affect brain function in adults. The WHO states, "Elemental mercury and methylmercury are toxic to the nervous systems (...); neurological and behavioral disorders can be observed after exposure."

Regular ingestion of methylmercury, even in small quantities, represents a serious health hazard, particularly for the brain development of fetuses and young children. Bloom emphasizes that current standards expose consumers to health risks above recommended safety thresholds, which are unjustified and related to economic considerations. "Mercury toxicity remains constant regardless of whether it is consumed via tuna or other sources," the NGOs state, emphasizing that "only the concentration of mercury in the food counts."

As a predator at the top of the food chain, tuna accumulate heavy metals from their prey, resulting in a significant increase in mercury contamination compared with smaller species. The larger and higher in the food chain a fish is, the more methylmercury it contains because it has eaten many smaller contaminated fish. Mercury accumulates in fish in its most toxic form, methylmercury, ending up on the shelves and then on the plates of millions of families.

Bloom and Foodwatch are calling on the European Commission to align tuna's maximum mercury content with the stricter 0.3 mg/kg limit applied to other fish species. They are also urging authorities to prohibit canned tuna and its derivatives in sensitive environments like schools, nurseries, retirement homes, maternity wards, and hospitals. Furthermore, the NGOs are requesting that supermarket chains remove tuna products from their stores with mercury levels exceeding 0.3 mg/kg, instead of the current standard of 1 mg/kg.

Camille Dorioz, director of campaigns at Foodwatch, summarizes, "We demand that public authorities strengthen the regulation and, without delay, that retailers only market products below the most protective threshold." Bloom and Foodwatch have launched a petition to encourage major retailers in France, such as Carrefour, Intermarché, and Leclerc, to implement stricter controls and to "assume their responsibilities" to "immediately protect the health of consumers."

The French National Agency for Food, Environmental and Occupational Health Safety (ANSES) explains that methylmercury is toxic to the human central nervous system, "especially during prenatal development and in early childhood." ANSES recommends consuming fish twice a week, varying species and sources, and limiting fish like tuna or pike for pregnant women, nursing mothers, and young children to reduce risks related to methylmercury. The World Health Organization states on its website that cooking fish does not eliminate mercury.

In light of various alerts regarding contamination by pollutants, doctor and columnist Jimmy Mohamed recently advised being cautious in fish consumption. His advice is to favor sardines, herring, and mackerel as alternatives for their similar nutritional qualities. These fish are smaller than tunas and salmons, so they are less exposed to contamination by pollution and would also have a reduced ecological impact.

Bloom emphasizes that current standards are not aimed at protecting public health but at maximizing the compliance rate of fish to keep them on the market. "Making people believe that eating tuna is safe from a health standpoint is an unforgivable lie with serious consequences," stated Julie Guterman, a researcher at Bloom and the lead author of the report. She added, "Mercury is a potent neurotoxin that adheres to the brain and is very difficult to eliminate."

Given the widespread contamination of canned tuna with mercury, the NGOs consider the findings a public health scandal and are demanding urgent action to protect consumers and reduce mercury exposure. They are also urging retailers to inform consumers about the health risks related to mercury contamination and to cease the promotion of tuna. Additionally, they request that public authorities implement urgent measures to prevent the marketing of all tuna that exceeds 0.3 mg of mercury per kilogram, aligning with the stricter limit applied to other fish species.

Sources: La Croix, El HuffPost, France 24, Femme Actuelle, GreekReporter.com, Elle, directoalpaladar.com, Home, Le Monde.fr

This article was written in collaboration with generative AI company Alchemiq