Metal exposure


​​Background (completed research project​)

Sustainability is the basic prerequisite for long-term high-quality food production. In agricultural production, sustainability depends largely on securing a balance between the nutrients that are added and food that is harvested. Equally, care must be taken to ensure that pollutants such as trace metals do not accumulate in the soil and in crops. As current studies have shown, metal inputs today are high enough to cause accumulations in the soil, even in Switzerland. The project uses a new method to analyse the sources of metals that accumulate in the soil, and their transfer into crops.


When metals accumulate in the soil, these can have an adverse effect on the quality and quantity of food produced. To counter this problem, the project aims to identify the biggest sources of metals. The investigation will focus on the three trace metals cadmium, copper and zinc, which occur in high accumulations in agricultural soils in some regions. As with most elements, these metals occur in the form of several stable isotopes. The ratio of isotopes can be used to identify and quantify the various sources of metals in the soil. These methods allow conclusions to be drawn about how the metals are transferred from the soil into crops. Using the isotope signatures, the sources of metals in the soil and in food crops can be detected and measures taken to reduce contamination.


The findings of the project will allow proposals to be developed about how to avoid metal accumulations in the soil and food crops. The recommended measures will be communicated to authorities, farmers and the general public in order to improve the sustainability of agricultural production.

Original title

Stable metal isotopes as tools to assess enrichment and sources of trace metals in soils and crops to improve sustainability of agricultural systems

Project leaders

  • Prof. Dr. Wolfgang Wilcke, Universität Bern
  • Dr. Moritz Bigalke, Universität Bern
  • Prof. Dr. Emmanuel Frossard, ETH Zürich
  • Dr. Armin Keller, Agroscope, Research Division Agroecology and Environment



Further information on this content


Prof. Dr. Wolfgang Wilcke Geographisches Institut der Universität Bern (GIUB) Raum 203a Hallerstrasse 12 3012 Bern +41 31 631 38 96