1. Department of Civil, Environment and Geomatic Engineering, University College London, Chadwick Building, London WC1E 6BT, UK
2. Policy and Practice, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK and Whittington Health NHS Trust, London, UK
3. Water, Sanitation and Hygiene (WASH), Climate, Environment and Energy, UNICEF, Eastern and Southern Africa Regional Office (ESARO), Nairobi, Kenya
4. Engineering for International Development Centre, Civil, Environmental and Geomatic Engineering, University College London, Chadwick Building, London WC1E 6BT, UK