the prospective toxic effects of some heavy metals overload in surface drinking water of dakahlia governorate, egypt

background: the concentration of heavy metals in drinking water is very important. objectives: to to evaluate the chemistry of some heavy metals in surface drinking water of dakahlia governorate, egypt. methods: 51 surface drinking water samples were collected from the main surface water stations and compact units in october 2009 and analyzed chemically. 26 water samples were analyzed by atomic absorption spectrophotometer for iron, manganese, lead, nickel, chromium, zinc, copper, cobalt, aluminum, and cadmium concentrations. results: aluminum concentration was slightly high in water sample of bosat network. cadmium concentration in samples of up-streams of shark and mit-khamis stations, networks of mit-antar, demera, bosat, bilqas, el-satamony, el-gamalia, mit-asim and bilqas station exceeded the permissible limits of egyptian ministry of health (emh, 2007) and world health organization (who, 2008). the nickel concentration in the network samples taken from shoha, bosat and el-gamalia as well as up-stream of bosat station exceeded the permissible limits. also, lead concentrations of the network samples of shoha, mit-antar, demera and nabaru exceeded the permissible limits. conclusion: regular chemical analysis of surface drinking water is required. since these heavy metals are most likely originate from steel, plastics and batteries industries working in the region, we believe that activities of these industries must be stopped or at least limited in urban zones.