Metal concentrations in drinking water used in Nablus have been studied . Samples from houses located in various districts of Nablus have been collected between Dec . 22,1985, and Jan . 19,1986 , acidified and then analysed for their metal content of the elements lead , copper , zinc , nickel , iron , manganese , calcium and magnesium using flame atomic absorption spectroscopy with an acetylene—air flame The results showed that the concentrations of lead , copper , nickel , iron and manganese were well below the safe limits . The concentrations of both zinc and magnesium were high but still below the maximum limit allowed in drinking water . The concentration of calcium was found always above the allowed limit . The effect of storing water in tanks ( this is very common in Nablus ) on the concentration of the above elements has been studied . The only effect found for storing water in tanks was a decrease in the concentration of zinc from water . No effect was found for using sun—heaters on the concentrations of the above elements in water .