Too Toxic for Kids to Eat: Banned in French Schools

Published September 17, 2025 by Gregory Dicum. Last Updated September 25, 2025.

This month, 13 million schoolkids in France are back in class after their summer vacations. And something is different in the lunch hall: Citing out-of-control toxic loads, schools in eight French cities, including Paris, have banned tuna.

French Schools Ban Tuna

The move comes on the heels of a report from the European environmental NGO Bloom that found that all canned tuna in Europe contains unacceptable levels of mercury.

Mercury is a metal that, in its pure form, is liquid at room temperature. It’s fascinating stuff that was once common in thermometers, light switches, batteries, and fluorescent bulbs. But when mercury gets into the ocean—mostly from human activities like burning coal and handling waste carelessly—it is absorbed by marine life and turned into methyl mercury, a highly bioavailable and toxic form that accumulates in the food web.

Tuna Are Incredible

Tuna are big, muscular fish who are among the fastest in the ocean—yellowfin tuna have been clocked at nearly 50mph! They use this speed to enable migrations that sometimes span entire oceans. Bluefin tuna have been tracked crossing the Atlantic in just a few weeks.

Humans exploit half a dozen tuna species for their flesh, including bluefin tuna. These remarkable animals can live for up to half a century. But bluefin populations in some areas are at less than three percent of levels without human interference.

Personally, it was watching a bluefin being dismembered by fishermen on a wharf in Cape Cod years ago that made me become vegan. I watched as men dropped the corpse of this gorgeous silver animal, weighing hundreds of pounds of solid muscle, on the pier; I could see the scars on her metallic face from the long fight with the hook in her mouth. Then I watched as the fishermen cut off the tuna’s head with a saw as a pair of eager Japanese buyers looked on. The next day, the fish’s body was probably in the Tokyo wholesale market, and I had sworn off eating all flesh.

Mercury Bioaccumulation

As small animals are eaten by larger ones, and larger ones again, persistent contaminants like methyl mercury accumulate in the tissues of the predators. As a result, top predators like tuna accumulate this and other toxins in their bodies at extremely high levels.

Not only is this bad for the tuna—mercury poisoning can damage the central nervous system, leading to difficulties swimming and catching food—but it can also affect humans who eat their tissue.

Mercury poisoning in humans is similar to what tuna experience. High levels can lead to weakness, tremors, mood changes, and cognitive impairment. At very high levels, it causes Minamata disease, a devastating neurological disorder that was first identified when homeless cats in Japan started to have seizures and die.

Even moderate levels of mercury in the diet can lead to birth defects and neurological damage in kids’ developing brains, so many dieticians recommend that people avoid eating tuna.

French Schools Take Lunch Seriously

What’s really shocking about the Bloom report is its finding that “safe” mercury levels in tuna are set by European regulators not at levels that avoid nerve damage (the safest level is zero), but at levels designed to allow most tuna into the market—levels higher than are allowed in any other fish. In other words, the guidelines cater to the needs of the violent and unsustainable fishing industry, not to the needs of public health.

Fortunately, French educators are more responsive to their students’ health. In 2022, they undertook a major sustainability overhaul of school meals, with half the ingredients now required to be from the region and 20% required to be organic. The new tuna ban is part of this move towards more sustainable and healthful school lunches in France.

Best of all, French schools are offering more vegan options. This is part of a global trend towards healthier school lunches. New York City, for example, has just released new school food standards that include a “plant-forward shift” in their menus. Vegan meals are always the most sustainable, with the lowest environmental impact and low levels of contaminants.