INTRODUCTION The protection of food is a serious problem for people globally 1 . Sewage water has gained importance in agriculture due to recycling of nutrients, despite this it contains unreliable quantity of potentially injurious matter that may cause severe diseases 2 . Compounds present in wastewater affect the hydro- logical properties of soil 2,3 . Heavy metal contamination has been amplified many-fold due to industrial revolution. Different diseases of humans are linked either with mineral shortage or with heavy metals toxicity 2,4 . Malnutrition also results in increased level of copper and it accumulates in liver resulting in decreased blood hemoglobin concentration and packed cell volume 5 . Iron functions as an important constituent of hemoglobin in the transport of oxygen. Deficiency of Fe may influence brain functioning by altering many metabolic processes that include haemosiderosis and haemochromatosis (bronze pigmentation of the skin) which Assessment of Potential Toxicological Risk for Public Health of Heavy Metals in Wheat Crop Irrigated with Wastewater: A Case Study in Sargodha, Pakistan ZAFAR IQBAL KHAN 1,* , KAFEEL AHMAD 1 , MUHAMMAD ASHRAF 2 , NUDRAT AISHA AKRAM 3 , YASIR RIZWAN 1 , MUNEEBA SHAHEEN 1 and FAHIM ARSHAD 4 1 Department of Biological Sciences, University of Sargodha, Sargodha, Pakistan 2 University College of Agriculture, University of Sargodha, Sargodha, Pakistan 3 Department of Botany, GC University, Faisalabad, Pakistan 4 Department of Botany, University of Education, Okara Campus, Okara, Pakistan *Corresponding author: E-mail: zikhan11@gmail.com (Received: 21 January 2013; Accepted: 16 October 2013) AJC-14258 In the present study, the concentrations of mineral elements in wheat (Triticum aestivum L.) plants was determined to observe the level of elemental pollution in Sargodha, Punjab, Pakistan as well as the abilities of the wheat plants to accumulate heavy metals from the soil supplied with sewage water. An experiment was conducted to study the transfer of heavy metals to the grains of wheat cv. Milate-2011 grown in soil without sewage-sludge treatment (control) and soil supplied with sewage-sludge. A number of heavy metals in soil and wheat grains were analyzed and results showed that Cr (5.63-6.21 mg/kg), Pb (5.54-7.08 mg/kg), Cu (12.25-13.64 mg/kg), Zn (31.85- 36.4 mg/kg), Mn (31.58-32.67 mg/kg) and Ni (3.43-4.32 mg/kg) were found in canal and sewage water irrigated wheat grains, respectively and were much higher than the toxic limit showing a severe risk of health. The Fe level (25.06-27.11 mg/kg) was below the toxic level, while Cd (0.02-0.03 mg/kg) level exceeded the maximum tolerable limit particularly for children i.e., 0.002-0.025 mg/kg. While soil Cr (24-36 mg/kg), Pb (80.21-94.84 mg/kg), Cu (23.4-28 mg/kg), Zn (65.2-72.8 mg/kg), Mn (62.8-73.2 mg/kg), Ni (23.4-25.5 mg/kg) and Fe (80.21-94.84 mg/kg) were found in canal and sewage water treated soil, respectively during this investigation and soil Cr, Cu, Ni and Zn levels were below the maximum permissible limits for soil, while the reverse was true for other metals. A significant correlation was found between the concentrations of metals in soil as well as their accumulation in grains except Fe concentration. The bio-concentration factor of these heavy metals was higher in wheat grains, so domestic sewage water may lead to heavy metal toxicity in humans if used unprocessed for irrigation purpose. Key Words: Heavy metals, Sewage water, Wheat, Maximum tolerable limits. are caused by extreme buildup of Fe in the vital organs. Manganese is an important cofactor for several enzymes 6 and is indefinite in humans. Adverse influences have also been reported on central nervous system due to Mn over exposure 7 . Zinc occurs in all living cells and it is distributed widely in animal and plant tissues. It acts as a cofactor and is a part of numerous enzymes 8 . Toxicity disorders of zinc in human beings comprise vomiting, gastrointestinal irritation, a decrease in high density lipoprotein (HDL) cholesterol and a decreased immune function. Nickel is a necessary constituent in animals 9 . One of the important environmental and industrial pollutants is lead. As suggested by different studies that declining repro- ductive health and ecological pollutants like lead have a close relationship 10 , while today a serious public health problem is the human exposure to lead 11 . In ruminants, Pb causes noxious consequences 12 . The objective of the present study was to investigate the effect of domestic sewage water being used for Asian Journal of Chemistry; Vol. 25, No. 17 (2013), 9704-9706 http://dx.doi.org/10.14233/ajchem.2013.15180