Paul J. Milham, Timothy E. Payne, Barry Lai, Rachael L. Trautman, Zhonghou Cai, Paul Holford, Anthony M. Haigh, and Jann P. Conroy (2007). Can synchrotron micro-X-ray fluorescence spectroscopy be used to map the distribution of cadmium in soil particles? Australian Journal of Soil Research 45, 624-628

Summary

Paul Milham from NSW DPI leads an international team, including scientists from the Australian Nuclear Science and Technology Organisation, and the University of Western Sydney, examining the distribution of cadmium in soils at the micro-scale.

Plants take up cadmium, a toxic heavy metal, from the soil and concentrations in some plant products contribute to osteoporosis and cancer in humans. Management of cadmium in diets is difficult, as uptake by plants is poorly predicted by current methods of cadmium measurement in soils. One reason posited for the poor accuracy of predictions is that cadmium may be distributed unevenly through soils.  Until our work this hypothesis was untested and testing required measurements using a powerful beam of x-rays from a synchrotron.

A competitive grant through the Australian Synchrotron Research Program (ASRP) paid for travel to and ‘beam time’ at the Advanced Photon Source (APS), Argonne National Laboratories, USA. Synchrotron time is scarce and the study was allocated 72 hours. This sleepless marathon resulted in the first maps of cadmium in soil particles and a scientific paper in the Australian Journal of Soil Research.

The team is preparing a second application to ASPR for time at APS to investigate cadmium distribution and to examine how cadmium atoms are bound to soil components. This information can be used to further understand the chemistry of cadmium in soils and will eventually lead to ways of ameliorating soils to prevent accumulation of this toxic metal in plants.