Determination of Heavy Metal Contents of Some Over the Counter Staple Food Items

Abstract

The contents of some heavy metals i.e. iron, copper, chromium, lead, cadmium and cobalt were determined in some over the counter food items by atomic absorption spectroscopy. Pulses, rice, wheat and their processed products contribute to a major portion of daily food intake by a very large segment of population of Pakistan. There was variation in metal contents in the same kind of variety purchased from different food stores which can be attributed to the soil conditions, water sources, manure and pesticides and processes used. The concentration of Fe(II) ranged from 78-118 mg kg^-1 on dry weight basis, where as that of Cu(II) ranged from 9.0-21.5 mg kg^-1. The concentration level of Cr(III) was from 115.0-368.0 mg kg^-1. While concentration of Co(II) and Cd(II) and Pb(II) varied slightly from sample to sample and ranged between 11.5- 15.0 mg kg^-1, 0.5-2.0 mg kg^-1 and 1.1-1.5 mg kg^-1, respectively. Daily intake limits were calculated and compared with MRL (minimum risk level) values given by ATSDR (2001). Results showed that the concentrations of Cr(III) and Pb(II) of all samples under study were much higher than those of MRL values. Thus intake of these food items in excessive amounts can cause accumulation of these hazardous metals in the body and pose a great health risk.