Cadmium in Our Plates: Levers and Innovations to Limit Its Presence in Food

In a report published in March 2026, Anses (French National Agency for Food, Environmental and Occupational Health Safety) reveals that part of the French population is overexposed to cadmium through their diet. For non-smokers, diet accounts for up to 98% of cadmium exposure. The culprits are everyday foods: wheat and cereal products (bread, pasta, biscuits, pastries, breakfast cereals...), as well as rice, potatoes, and certain vegetables.

The problem: cadmium has health consequences. It is classified as carcinogenic, mutagenic, and toxic for reproduction, and prolonged exposure to this metal, even at low doses, is associated with kidney damage and bone fragility, increasing the risk of osteoporosis and fractures. Anses estimates that a significant portion of the population exceeds health reference values during their lifetime, and in the absence of measures to reduce exposures, the long-term harmful effects could affect an increasing share of the population.

Where does this cadmium come from? It is naturally present in soils, in varying amounts depending on the nature of the rocks from which they originate. However, human activities also contribute to its presence. Metallurgical, chemical, and electrical industries, as well as waste incineration, are sources of environmental discharge. In agriculture, mineral phosphate fertilizers and livestock effluents are additional sources. To sustainably limit soil and food contamination, Anses recommends acting at several levels: favoring phosphate rocks low in cadmium or resorting to their decadmization, adjusting the type and quantities of fertilizing materials used according to soils and crops, mobilizing phosphorus already present in soils, or developing plant varieties that accumulate less of this metal.

Here, we have identified five levers of action based on agronomic, genetic, and industrial innovations: mobilizing phosphorus from soils, genetic innovations, soil mineral balance, phytoremediation, and decadmization of fertilizers. We break down, point by point, their mechanisms of action to understand how they can contribute, at different levels, to limiting the presence of cadmium in food.

1. Mobilizing phosphorus already present in soils

To lower the cadmium content in food, one avenue is to better utilize the phosphorus already present in soils to limit additional inputs of phosphate fertilizers, which can naturally contain cadmium. Some soils have a significant reserve of phosphorus, but it is not necessarily available in a form that plants can use. Therefore, various mobilization techniques exist, based on the use of fungi (Trichoderma) or bacteria such as Bacillus, Pseudomonas, or Burkholderia.

Hicham Ferhout, research manager in microorganisms for Agronutrition, summarizes this as a mutually beneficial exchange: the plant provides carbon to the bacteria, which can grow and, by multiplying, make the phosphorus in the soil available. Depending on the form in which it is present, it can either solubilize mineral phosphorus or mineralize organic phosphorus.

"Bacteria solubilize phosphorus in different ways, depending on the soil pH, he explains. If the pH is acidic (low, editor's note), phosphorus is blocked by iron and aluminum in the soil. If the pH is high, it is blocked by calcium". In this case, "bacteria produce organic acids that locally decrease the pH and cause the separation between phosphorus and calcium, making phosphorus available. At acidic pH, bacteria produce iron complexing agents and release phosphorus". In other words, these molecules bind to iron, releasing the phosphorus to which it was associated. A third mechanism concerns organic phosphorus (contained in organic matter and not complexed with other minerals) that does not depend on pH. It is a complex organic molecule that stores several phosphorus atoms and that plants cannot use directly. A particular enzyme (phytase) produced by bacteria "will degrade this molecule" and release the phosphorus it contains. Phytases are already used industrially to limit the level of phytic acid in certain food products derived from soy, as it limits the absorption of iron by the human body.

Some processes are sometimes complex to popularize, as explained by Christophe Richou, development and marketing manager at Agronutrition: "There is a lot of work to be done to raise awareness among farmers about these new technologies that are very innovative but require new approaches". However, he reports a growing sensitivity among farmers to input economy and the natural valorization of soils.

In the long term, Agronutrition is also working on bacteria that have the dual function of solubilizing phosphorus and blocking cadmium already present in the soil so that the plant does not absorb it. "It is important to understand that cadmium in the soil, when it is already present, cannot disappear. So the main method is to limit its assimilation by the plant. Some will also limit the cadmium content of their fertilizers. (...) I believe that by activating all these levers, we will succeed,” concludes Hicham Ferhout.

2. Genetic innovations

A second solution to reduce the cadmium content in food lies in genetic innovations and the identification of cereal varieties and other crops that accumulate low levels of cadmium.

The challenge is to determine whether, placed in the same environmental conditions, some varieties naturally accumulate less cadmium than others. Vincent Pétiard, geneticist and member of the French Academy of Agriculture, takes the example of cocoa: "If we put 100 different varieties of cocoa in the same field with a certain cadmium content in the soil, do they all accumulate the same level of cadmium in the beans? The answer is no". And the variability in cadmium accumulation rates among varieties can be very significant "ranging from almost zero to ten times or more than the authorized level in the beans", he specifies.

Once the properties of the varieties are identified, it is possible to choose to use only the one that accumulates the least. However, it may not meet certain yield or quality requirements. The solution then is to combine, through traditional breeding and crosses, the characteristic of low cadmium accumulation with those of another high-yielding but too accumulating variety, to combine the desired characteristics in one variety. Finally, in the long term, if the genetic determinants of cadmium accumulation are identified, it is possible to consider using new genomic techniques to change this characteristic in varieties of interest that are too rich in cadmium. The simplest solution is to use, if it exists, a variety that accumulates very little cadmium, minimizing the risk of exceeding regulatory thresholds.

This approach is already being implemented for durum wheat, a crop pointed out for its cadmium accumulation, as it is part of the composition of widely consumed foods, such as pasta and semolina. Canadian researchers have identified two variants of the same gene, one favoring cadmium accumulation in grains, the other limiting it. This gene, named CdU1, is involved in cadmium retention in roots and subsequently reduces its concentration in grains by two to three times.

Building on this work, Christophe Nguyen, research director at INRAE Bordeaux, a specialist in biogeochemistry, plant ecophysiology, and modeling, explains: "We have found, in French varieties, the gene responsible for higher or lower accumulation. It is possible to determine which version of the gene each variety possesses through a fairly rapid genetic analysis". According to him, in France, since the end of the 2010s, the increasing use of durum wheat varieties with the low accumulation trait has reduced the average contamination level of crops by about 40%. Some crops have cadmium levels nearly three times lower than the regulatory threshold of 0.18 mg/kg of grain set by Europe.

Beyond varietal selection, this knowledge has been used to develop a decision support tool. INRAE Bordeaux and Arvalis, a private agricultural technical institute specializing in field crops, have launched "Bléssûr", a tool that predicts the risk of non-compliance of a future durum wheat harvest based on the variety sown and the soil analysis complemented by its cadmium content.

3. Soil mineral balance

Cadmium enters plants primarily by using root transporters for iron and zinc, two trace elements essential for their development. Therefore, the soil mineral balance constitutes another lever that can be adjusted to reduce the amount of cadmium absorbed by a plant.

A plant deficient in iron and zinc will "increase its capacity to absorb these two trace elements, simultaneously increasing cadmium absorption ,” specifies Christophe Nguyen, research director at INRAE. By adjusting the soil mineral balance, the principle is to make these two trace elements more available to the plant so that it does not find itself in a state of deficiency.

According to the specialist, in France, we act more on the soil mineral balance through fertilization for major elements such as nitrogen, phosphorus, potassium (NPK), or sulfur. But in terms of trace elements and cadmium mobility, it is different. "Soil pH plays a decisive role, he explains. The more acidic the soil, the more mobile cadmium is and likely to be absorbed by the plant. But if we increase the pH too much, particularly through liming, there is a risk of making certain elements like iron or zinc very inaccessible to the plant". The goal is therefore to maintain a soil pH close to neutrality (between 6.5 and 7), being careful with fertilizers that can acidify the soil.

One avenue being studied would be to add organic matter that would gradually release trace elements: "when this organic matter mineralizes, that is, when microorganisms degrade it, trace elements are released and the biological activity associated with organic matter tends to stabilize a pH close to neutrality. Negatively charged organic matter helps bind the positively charged cadmium ion, making it less available to the plant. But this does not always guarantee a decrease in plant contamination, he notes. Moreover, the organic matter we add also contains cadmium." He continues: "Reducing the level of cadmium in crops is something quite complex that is difficult to control precisely".

A study published in 2024*, in the scientific journal Environmental Pollution, particularly highlights the complex interactions between zinc and cadmium. The results show that zinc often limits cadmium absorption when soils are deficient in zinc. However, this relationship strongly depends on soil characteristics. Under certain conditions, particularly when the concentrations of both elements increase simultaneously, the opposite effect can be observed. It also shows that iron deficiency induces the expression of genes that can promote cadmium absorption by rice roots. An iron input can therefore be beneficial, but it is necessary to control the chemical form of iron present in the soil, which can either immobilize iron and increase cadmium mobility in the soil or increase the availability of iron for plants while limiting cadmium absorption by crops.

The mineral balance therefore does not offer a universal solution. It is rather a lever that must be adjusted on a case-by-case basis, depending on soil characteristics, particularly its pH, which strongly influences the absorption capacities of trace elements and cadmium, and the interactions between mineral elements.

^{*Enhancing soil health to minimize cadmium accumulation in agro-products: the role of microorganisms, organic matter, and nutrients. / Junliang Xin}

4. Phytoremediation

When cadmium is already present in significant amounts in soils, another approach is not to limit its transfer to the plant, but to directly reduce soil contamination: this is phytoremediation. It refers to a set of techniques using plants to remove contaminants from the soil. In the case of cadmium, the technique that works to date is phytoextraction. It involves having certain plants known as hyperaccumulators absorb metals like cadmium through their roots, so they store it in their stems or leaves, which are then harvested.

Claire Hazotte, director of the company Econick, uses phytoextraction as part of her activity of extracting metals from soils. For each metal, a specific plant is chosen for its effectiveness. For cadmium, Noccaea has been identified. A small herbaceous plant with white flowers more commonly known as the stool plant. "We always try to use endemic plants on our plots when detoxifying soils,” she specifies. Interventions always begin with a soil analysis. Once the area is mapped and the pollutants identified, the plants are put in the ground. "We let them grow, so they have time to accumulate the metals present in the soil. The roots act as vacuums, and the metals are sent to the aerial parts: leaves, stems, and flowers. Then, at the end of the season, we cut the aerial part,” describes Claire Hazotte. For some metals like zinc or nickel, the goal is then to extract them through hydrometallurgical processes (without the use of solvents) for valorization.

"For cadmium, there is currently no possible valorization, she indicates. Initially, valorization was focused on nickel-cadmium batteries used in medical and railway applications. But all of that has stopped in favor of other batteries. Cadmium is classified as CMR, carcinogenic, mutagenic, and toxic for reproduction, so no one wants it. It must go to hazardous waste".

While these plants reduce the pollution rate locally, total depollution is not feasible solely through this technique, and according to Claire Hazotte's experience, several years are needed, depending on the initial soil contamination, to achieve a significant result: "We worked on an agricultural soil where there was a shared garden of companies contaminated with zinc and cadmium. After three years, we observed a significant decrease in concentration,” she indicates.

While Econick now aims to mechanize this technology to treat larger areas, Claire Hazotte notes that farmers are still hesitant to communicate about the contamination of their soils. Some prefer to keep these processes confidential, while others agree to use them as a tool for raising awareness among their colleagues, individuals, or elected officials. "We don't want to say that our soil is contaminated with cadmium. We need to overcome the barrier of what people will say,” she specifies. However, municipalities are increasingly using phytoremediation methods.

5. Decadmization of fertilizers

Unlike approaches aimed at directly acting on soils, decadmization occurs at the fertilization level. Its goal: to reduce the amount of cadmium present in phosphate fertilizers. In terms of producing "low cadmium" fertilizers, the Moroccan Phosphate Office (OCP), a Moroccan industrial group, has become, by necessity, a specialist.

Moroccan phosphate fertilizers are among the richest in cadmium. In anticipation of new European regulations aimed at limiting cadmium levels in mineral phosphate fertilizers, the group has invested in developing a decadmization process to continue selling its products on European soil. "Reducing cadmium in fertilizers has been one of our research focuses for several years, following the work carried out at the Center for Studies and Research on Mineral Phosphates, then reinforced with the ecosystem of Mohammed VI Polytechnic University,” communicates OCP Nutricrops.

According to a report from the French General Inspectorate of the Environment and Sustainable Development, published in February 2026, an investment of 60 million euros has been reported to develop these new techniques, which have led to the filing of several patents. "Nearly 47 technologies, at different stages of maturity, have been explored, developed, and tested, most of which are owned by the group, indicates OCP Nutricrops. Some are now deployed at the industrial level and intervene at different stages of the value chain: upstream, on phosphate rock, through selective extraction and enrichment processes such as washing and flotation; downstream, during phosphoric acid treatment, through processes using additives that capture and selectively separate cadmium".

Since July 16, 2022, the date of application of the European regulation establishing the rules regarding the marketing of fertilizers, to carry the CE marking and access the market of the 27 countries of the European Union, a phosphate fertilizer must contain less than 60 mg/kg of phosphorus pentoxide (P₂O₅).

OCP Nutricrops claims that since February 2025, all its fertilizers exported to Europe have a cadmium content of less than 20 mg/kg of P₂O₅, which is three times lower than the European regulatory limit. "The gradual integration of these decadmization processes into our production units, accompanied by the necessary industrial and operational adaptations, will allow us to extend the availability of our low-cadmium fertilizers to all the markets we serve by the end of 2027,” the group specifies in a statement.

These five approaches show that there is currently no single solution to limit the presence of cadmium in food. Sustainable reduction of exposure relies rather on a combination of levers, the choice of which depends primarily on the crop concerned and its ability to accumulate cadmium, but also on soil characteristics, its composition, and its cadmium content. A geographical shift to a soil less rich in cadmium or the use of low-accumulating varieties when available often constitutes the most direct lever. In other situations, mobilizing phosphorus from the soil, managing its mineral balance, or phytoremediation can complement this strategy. Decadmization serves another purpose: to limit future cadmium inputs when the use of phosphate fertilizers is essential.

Alongside the levers mobilized upstream of production, Anses also emphasizes the importance of acting on the food supply, particularly by favoring less contaminated imported products. At the individual level, it also recommends diversifying one's diet and favoring foods that generally have low cadmium levels, such as legumes (lentils, chickpeas, white beans, flageolets), fruits, white-fleshed fish, or dairy products.