Cadmium: take action immediately at the source of soil contamination

Widespread exposure via a large variety of everyday foods

The most recent data show an alarming situation in terms of cadmium exposure of the French population. The latest national biomonitoring study (ESTEBAN), published by Santé publique France in 2021 (data from 2014–2016), indicated higher cadmium contamination levels than the previous survey (National Nutrition & Health Study 2006-2007). More recently, ANSES's third total diet study (TDS3) also revealed dietary exposure that remains high for part of the population of children and, to a lesser extent, adults. 

By aggregating the various routes and sources of exposure to cadmium, the ANSES expert appraisal was able to simulate current cadmium contamination levels in the French population, taking account of the lifelong accumulation of cadmium in the body. The results confirm that a significant proportion of the population exceeds the health reference values developed by the Agency. These are biological (blood, urine) health benchmark values by age group, which correspond to contamination levels not to be exceeded at 60 years of age, given the bioaccumulative nature of cadmium in the body. 

"If current levels of exposure continue and no action is taken, long-term adverse effects are likely for a growing proportion of the population" explained Géraldine Carne, coordinator of the expert appraisal at ANSES. 

In its assessment, ANSES examined all the possible sources of exposure: food, water, air, dust, soil, cosmetics and smoking, as well as the different routes of exposure (ingestion, inhalation, skin contact). The results confirm that food is by far the main source of exposure, accounting for up to 98% of cadmium contamination levels in the non-smoking population. The foods that contribute the most are products that are both commonly consumed and contaminated by cadmium, particularly certain cereal products (breakfast cereals, bread and dry bread products, croissant-like pastries, pastries, cakes and sweet biscuits, pasta, rice and wheat), as well as potatoes and certain vegetables.

For smokers, tobacco is a further source of cadmium contamination.

Apply cadmium limit values for fertilisers as soon as possible

The in-depth analysis of the different sources of exposure, supplemented by a socio-economic analysis, enabled ANSES to identify some priority courses of action, taking account of their impact and the challenges arising from their implementation.

This showed that action needs to be taken first and foremost at the source of food contamination, which is largely due to the presence of cadmium in agricultural soil. High cadmium inputs to soil mainly result from the use of fertilisers, particularly mineral phosphate fertilisers. In France, their extensive use, combined with certain sources of supply that may contain high levels of cadmium, has contributed to this metal accumulating in soil. 

To reduce this contamination, ANSES calls for cadmium limit values for fertilisers to be applied as soon as possible, to enable pollution of agricultural soil and contamination of foodstuffs to be controlled and the population's dietary exposure to eventually be reduced. To achieve this, the Agency reiterates the values it recommended in 2019 for fertilisers applied to agricultural soil: not to exceed a cadmium inflow of 2 g per hectare per year. To comply with this threshold, a maximum content of 20 mg of cadmium per kilogram of P₂O₅ in mineral phosphate fertiliser products is recommended.

Several courses of action to reduce soil and food contamination over the long term

To reduce cadmium inputs from mineral phosphate fertilisers marketed in France, the Agency recommends obtaining phosphate rock or derived products from sources containing less cadmium. Where this is not possible, it advocates the use of cadmium removal processes, while taking care to ensure the quality of the fertilisers obtained. The Agency also recommends revising the labelling of fertilisers to include a mention of their cadmium content.

In addition, ANSES strongly supports the promotion of new agricultural practices, such as adjusting the type and amount of fertilisers applied according to the soil or crop, deploying techniques to make use of phosphorus already in the soil in order to avoid new inputs, and opting for plant varieties that accumulate less cadmium.

Implementing these measures will require the commitment of all stakeholders to adapt the regulations, support the agricultural sector and strengthen monitoring of cadmium levels in fertilisers in France over time, in particular through a national monitoring database. 

Lastly, the Agency stresses the importance of also taking action on the food supply, including imported products. It therefore recommends in the medium term revising maximum cadmium levels for the foods that contribute the most to exposure, in order to reduce the population's overall exposure regardless of the origin of these foods.