HEAVY METAL CONTENTS OF LOCALLY GROWN GRAINS

Abstract

Essential/non-essential heavy trace metal and macronlltrjent contents of fifteen different grains procured from local markets/fields of Punjab and NWFP were estimated and reported . The estimated non-essential metals included Cd, Cr, Pb, Hg, Ni and As, while the macro-nutrients studied were K, Na, Ca and Mg. The micronutrients investigated were Fe, Cu , Mn and Zn. The relevant soil samples were also analysed f or the above mentioned metals along with their organic matter content and pH values. The food grains investigated were: wheat, rice, maize, barley, gram (white), gram (black), bean (white), bean (red), mong, masur, mash and dal chana. The data are computed at 99% L' s) confidence level for triplicate measurements and reported with an overall reproducibility within ! 1%. The study revealed that the bean and mong are good sources of macronutrients, K, Ca, Mg and Na, while gram and mash are rich sources of Fe, Zn and Cu at the level of 44.200, 49.050 and 8.125 mg/kg, respectively. Wheat has the highest Mn content in all the food grains analysed from both the provinces. It was found that, generally, all the food grains are either free from or low in heavy toxic metals burden. However, Ni and Cr conte nts of gram (white ) and bean (red), from NWFP, were exceptionally hjgh, at 2.710 and 3.800 mg/kg, respectively, on dry weight basis.