Shoppers buying fresh vegetables from the maze of stalls at Dar es Salaam's Kariakoo market have no idea of the risks they are taking, but food safety officials are alarmed by the chemicals and effluent in the water used on the city's urban farms.
Doreen Nkya always buys some spinach or amaranth on her way home because she considers them an important part of her family's diet. "I like vegetables because they are healthy. We don't often go without them at our dinner table," she said.