SPECADIS · Speciation and bioavailability of heavy metal cadmium (Cd) in the soil-plant system: a novel approach combining stable isotope geochemistry and experimental spectroscopy.

Speciation and bioavailability of heavy metal cadmium (Cd) in the soil-plant system: a novel approach combining stable isotope geochemistry and experimental spectroscopy.

The environmental pollution by ecotoxic heavy metals (e.g. mercury, lead) is a problem of increasing significance for ecological, evolutionary, nutritional, and, ultimately, human health reasons. Among these elements, cadmium (Cd), a transition heavy metal, is of special concern due to its relatively high mobility in soils and soil/plant systems and its acute toxicity toward almost all forms of life, even at low concentrations. According to the World Health Organization, human exposure to cadmium is a major public health concern. In Europe, a significant part of the population is already overexposed to that metal via the consumption of potatoes and wheat-derived products. To limit Cd contamination in plants and food products, and enhance food safety, it is primordial to understand how Cd is transferred from the soil to the plant and what controls its bioavailability. Previous studies demonstrated that the mobility and bioavailability of Cd in the soil/plant system – thus its toxicity in this system – depends ultimately on its chemical speciation. In this context, the development of direct, experimental characterization of trace elements speciation by X-ray absorption spectroscopy has brought key information on heavy metal behavior in the critical zone and keep on unravelling what controls their bioavailability. However, applying this cutting-edge methodology to the experimental determination of Cd speciation in biological samples remains challenging: in most organisms, due to Cd acute toxicity, Cd concentration lies below the technical detection limit of most X-ray absorption beamlines. That is why, at the starting date of the SPECADIS project, Cd speciation determination had only been carried out on Cd-hyperaccumulating and/or Cd-tolerant systems. The overarching goal of SPECADIS was to bypass these technical difficulties to measure Cd speciation in natural plant samples by developing an indirect tracer of Cd speciation relevant to the soil/plant context: Cd stable isotopes. In addition, SPECADIS aimed at investigating the uptake mechanisms and fate of cadmium in plants, and bringing new constraints on Cd toxicity/detoxification in plants that feed the world.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз