ABSTRACT
Environmental Science Unit, Department of Geography, Queen Mary and Westfield College, University of London, Mile End Road, London E1 4NS, UK
Cadmium has no known essential biological function and is potentially toxic to both plants and animals. This paper reviews the behavior of Cd in the human food chain. The transfer of Cd along the soil-plant-human pathway is considered for soils that have been treated with sewage sludge. Only the soil-plant human pathway is considered because food crops dominate the human Cd exposure profile. The importance of this mode of soil contamination is placed in both a regional and global context. Consideration is given to the key processes deter mining the dynamics of Cd in agricultural systems. Cadmium concentrations for two key food groups, potatoes and cereal crops are reviewed. Soil factors affecting the bioavailability of Cd to crop plants are reviewed. The contribution of Cd from the atmosphere to the overall Cd burden of the plant is examined. The prediction of Cd concentrations in food crops is examined with reference to the use of predictive models and diagnostic soil testing procedures.
