The news that tuna is banned in school cafeterias in several French cities has spread worldwide and raised alarms.
This decision, which includes Paris, Lyon, and Lille, is based on a precautionary principle due to concerns about children’s health, given the mercury contamination.
Although the products comply with current health regulations, municipal authorities considered that the current European regulation does not offer adequate protection.
Concern about mercury in tuna: the decisive decision of French cities
The measure was driven by the activism of environmental organizations such as Bloom and Foodwatch, which warned about the presence of mercury in tuna. These associations, after analyzing 148 cans of canned tuna, found mercury in all samples.
In more than half of them, as reported by the EFE agency, the concentration exceeded 0.3 milligrams per kilo, a limit established for other fish such as cod or anchovies.
Although European regulations allow a maximum concentration of one milligram per kilo in fresh tuna, environmental organizations point out that this limit rises to 2.7 milligrams per kilo in canned tuna, as mercury becomes concentrated when dehydrated.
For this reason, French cities will maintain the ban until the authorized mercury limit in tuna is reduced to the same level as other fish, that is, to 0.3 milligrams per kilo.
Industry’s stance and what the WHO says
The World Health Organization (WHO) identified mercury as one of the 10 chemicals of major concern for health, with a particular risk for children.
Meanwhile, the Federation of Canned Food Industries defended the safety of their products, stating that they comply with all regulations.
However, the industry questioned the methodology of the analyses carried out by NGOs and published the results of their own controls. In these, they claim that mercury concentrations are, on average, three times below the regulatory threshold.
Mercury levels in rivers doubled: causes and consequences
A recent study reveals a concerning fact regarding the planet’s water. From 1850 until now, mercury levels in rivers have doubled.
The research was published in Science Advances and led by researchers from the University of Nanjing and Tulane University.
Tuna banned in schools in some French cities due to mercury levels.
It reveals that the substance levels transported by rivers to the ocean have increased from about 390 tons to over 1000 today, more than double the pre-industrial era.
Mercury in rivers: report findings and why it’s concerning
Using the global model MOSART‑Hg, scientists measured the riverine mercury flux from the preindustrial era to the present. They validated their projections with marine sediment data.
This meticulous analysis determines that today rivers carry almost a thousand tons of mercury annually. This represents a 150% increase, mainly driven by industrial discharges, mining, and accelerated soil erosion.
The most affected regions are North and South America, responsible for 41% of the global increase, followed by Southeast Asia (22%) and South Asia (19%).
