1. Environment & Health Research Unit; South African Medical Research Council; Department of Geography, Meteorology and Geoinformatics; University of Pretoria; Pretoria South Africa
2. Department of Chemistry and Chemical Biology; Cornell University; Ithaca NY USA
3. Occupational Hygiene and Health Research Initiative; North-West University; Potchefstroom South Africa
4. Cancer Society of New Zealand Social and Behavioural Research Unit; Department of Preventive and Social Medicine; University of Otago Medical School; Dunedin New Zealand
5. Environment & Health Research Unit; South African Medical Research Council; Pretoria South Africa