Why eight cities in France are banning tuna in school canteens

Cities across France have taken tuna off of school menus amid fears of high mercury levels in the fish. 

Eight mairies have come together to remove the popular fish from school meals when children go back to school next week (the rentrée is on Monday September 1). 

The cities taking the decision are: Paris, Lille, Lyon, Bègles, Grenoble, Montpellier, Mouans-Sartoux, and Rennes.

The decision to ”temporarily remove” the fish from menus comes after consumer rights watchdogs Bloom and Foodwatch raised warnings last year over potentially dangerously high levels of mercury in tinned tuna across Europe. 

Mercury is classified by the World Health Organization as one of the 10 most dangerous chemicals threatening public health.

“No action has been taken by national and European political leaders or the tuna industry to protect consumers, especially children,” since the report, said the city authorities over their decision. 

A press release announcing the change was signed by the deputy mayors responsible for food in each of the cities and sent to the public service radio France Inter.

“Mercury is a neurotoxin with an effect on brain development, particularly in children,” said deputy mayor in Lille Marion Gauthier to the radio station. 

“We try to be consistent and serve food that respects both health and the environment and when we receive alerts like this, we cannot ignore them,” added deputy mayor in Mouans-Sartoux Gilles Pérole. 

“We apply the precautionary principle. We want the healthiest food possible for our children. We see that it's becoming increasingly difficult,” he added.

All food for school children in the Alpes-Maritimes commune is already 100% organic.

One portion per week puts consumer above safety threshold

Tuna will remain off of school menus in the cities until regulations on mercury levels in tuna align with those for other fish, the deputy mayors said.

Officials want a limit of 0.3mg of mercury per kg in place for tuna – the current limit for other fish such as sardines and cod – to be implemented.

In comparison, this threshold is nearly quadrupled to 1mg per kg of mercury for tuna, and in the 2024 report, several tinned variants were found to be significantly above this increased threshold. 

Eating just one portion of tuna per week could put an adult (weighing 79kgs) above the EU-defined safety threshold for mercury consumption. 

It is also worth noting that the EU-defined tolerable limit for mercury is nearly double that of its US counterpart (1.3 micrograms of mercury per kg of body weight, compared to 0.7).

“The matter is therefore serious, and it is the moral duty of the state and elected officials to protect citizens, starting with children,” said the cities to France Inter. 

It has called on French MPs to move towards lowering legal limits, both within France and at a wider-EU level.