Abstract
This research work was performed in the poorest urban area of Cairo (Egypt) in a slum area called Al-Quarafa. The aim was to develop and evaluate a simplified hydroponics system (HS) to grow vegetables for the local inhabitants who live in an extreme status of food unsafety. In the hydroponic growing system the tomato plants were cultivated and two substrates were compared: peat:perlite (70/30 W/w) and sand:coir (50:50 W/w). This technique guarantees high levels of production and low contamination by avoiding the use of polluted urban soils which are often common in slum areas. Macro and microelements in tomato fruits were analysed by ICP-MS. Results showed low concentrations of heavy metals (Cd, Sr, As, Cr, Mo) with all heavy metals under the levels set by European Community laws. Lack of food safety in slums is more closely linked with malnutrition than starvation, so it is also important to understand mineral availability (both micro and macro) and nutritional significance for health. For this reason micro and macro elements (K, Ca, Na, Fe, Mn, Mg, Cu, Zn) were analysed in the harvested fruits. This study showed that HS is a valid method to grow vegetables in urban areas to improve food security in Middle East cities.
