Fumonisin exposure biomarkers in humans consuming maize staple diets by Liana van der Westhuizen Dissertation presented for the degree of Doctor of Philosophy (Medical Biochemistry) in the Faculty of Health Science at the University of Stellenbosch Promoter: Dr Gordon S Shephard PROMEC Unit, Medical Research Council Co-promoter: Prof. Paul D. van Helden Faculty of Health Science, Department of Biomedical Sciences, Division of Molecular Biology and Human Genetics March 2011