1. Environmental Chemical Pollution and Health Research Unit, School of Health Systems and Public Health, University of Pretoria, Private Bag X323, Arcadia 0007, South Africa
2. Environmental Chemical Pollution and Health Research Unit, Department of Urology, University of Pretoria, Private Bag X323, Arcadia 0007, South Africa
3. Central Analytical Facility, Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
4. Council for Scientific and Industrial Research: Natural Resources and the Environment, P.O. Box 320, Stellenbosch 7599, South Africa