Following the investigation by the NGOs Bloom and Foodwatch which revealed the presence of mercury in canned tuna purchased in Europe, the programs On en rapport and A Bon Entendeur wanted to know what the situation was in Switzerland. The 55 samples tested all contain mercury, but remain within legal limits.
Laboratory analyzes of 55 cans of tuna from Migros, Coop, Lidl, Aldi, Denner and Manor showed that each sample contained mercury, but at levels below the Swiss legal limit of 1 mg/kg for mercury. tuna.
The results also show a notable variation in the mercury content between the different boxes, with a maximum concentration of 0.5 mg/kg and a minimum of 0.02 mg/kg.
Valais cantonal chemist Linda Bapst considers these levels “rather reassuring” compared to theinvestigation by the NGOs Bloom and Foodwatch published at the end of October.
>> Read about it: Canned tuna widely contaminated with mercury in Europe, NGOs denounce
>> The results of the analyzes carried out by the programs On en parole and A Bon Entendeur:
A limit to respect
The presence of mercury, however, implies health recommendations for consuming canned tuna without danger. As Linda Bapst reminds us, we should not exceed one box every two weeks for an adult or one box per month for children. For children under 4 years old and pregnant women, the consumption of canned tuna should even be completely banned.
“We know that there may be a risk of specific neurotoxicity on the developing fetus and on small children, a risk of delay in terms of brain development, even at lower doses”, specifies doctor Myriam El Biali , specialist in pharmacology and toxicology at the University Hospitals of Geneva (HUG).
A substance naturally present in the oceans
Mercury is present in the oceans due to its natural presence on Earth, but also due to human activity. Tuna being a predator, it will accumulate in its flesh the mercury from the fish it consumes, which explains its higher concentration compared to other fish such as sardines or trout.
Myriam El Biali explains: “Mercury is essentially present in fish in the form of methylmercury, the main risk of toxicity of which is at the cerebral and peripheral nerve level. It causes neurotoxicity which will manifest itself mainly by sensations of tingling in the limbs, we can develop tremors, fatigue, dizziness and, in very severe cases, this can lead to cognitive disorders.
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Standards to review?
If a maximum mercury limit of 1 mg/kg is tolerated in tuna, this is not the case in other fish such as cod, salmon, sardines or trout, for example, which are limited to 0.3 mg/kg.
Asked about the method of setting these rates, the Federal Office of Food Safety and Veterinary Affairs (FSVO) responds that “different factors are taken into account, among other things which contaminants are present in the different foods and at what concentration, or consumer behavior At the same time, the maximum values must be technically feasible and economical. A balance is thus found between health protection and practical feasibility.
For their part, the NGOs Bloom and Foodwatch denounce rates which are set more according to a compromise with the fishing industry than for reasons of public health.
The On En Parle and A Bon Entendeur teams
