A series of field experiments were used to determine the risks associated with applying biosolid cadmium (Cd) onto agricultural land. The soil to plant transfer of CA (wheat grain) was examined for a wide range of Australian soils under typical agronomic conditions. The solubility and bioavailability of CA in biosolids was assessed in relation to the behaviour of soluble Cd salts. Solu bility of biosolid Cd (measured by examining Cd partitioning between soil and soil solution) was found to be approximately equal to that of soluble Cd salts. However, bioavaitability of Cd to wheat and transfer to grain was less than that of soluble Cd salts. Critical CA concentrations in soil could be described by a combination of soil clay content and soil pH across a diverse range of Australian soils. This data show that some acidic sandy soils are high risk in relation to food chain accumulation of Cd and Australian guideline soil limits for CA should be adjusted accordingly.
food chain health bioavailability
M. S. Whatmuff M. J. McLaughlin M. Warne D. Heemsbergen G. Barry M. Bell D. Nash D. Pritchard
Centre for Environmental Contaminants Research, CSIRO Land and Water, Adelaide, SA School of Earth a Centre for Environmental Contaminants Research, CSIRO Land and Water, Adelaide, SA School of Earth a Centre for Environmental Contaminants Research, CSIRO Land and Water, Adelaide, SA Richmond NSW 2753 Department of Primary Industries and Fisheries, Kingaroy Qld 4610 Department of Primary Industries, Ellinbank VIC 3821 Curtin University of Technology, Muresk Institute, Northam WA 6401