Sohel Ahmed and Prof Muki Haklay at DPU and CEGE at UCL -- in cooperation with IIED and the Kenyan Federation of the Urban Poor -- have used balloon mapping and other mapping tools to capture exposure of food vending to environmental hazards in selected low income informal settlements in Nairobi, Kenya. See the Nairobi, Kenya wiki page with links to press coverage and white papers: https://publiclab.org/wiki/nairobi ...