Lead, Nickel and Copper Concentration and Related Factors in Some Uncooked Vegetables Irrigated by Wastewater

Population density of Erbil City, Northern Iraq (where this work was carried out) estimated as more than 2 million. The sewage discharge of the city may reach 77760m3/ day during low level and 108000m3/ day during high-level periods. About 225 hectares of scattered farmlands are used by local farmers for production of uncooked vegetables for local need, all of which are irrigated by untreated sewage water. In the present work, about 28 physical and chemical variables those related to sewage water quality were assessed on fortnightly bases for 7 months. Some toxic heavy metals, namely; Pb, Ni and Cu bioaccumulation rates in sewage, soil and some uncooked vegetables in five different locations/ farms were followed up (only bioaccumulation rates of Pb, Ni and Cu in lettuce, cress, dill and radish are given here) (Full data can be obtained from both authors). Onset results revealed that Pb, Ni and Cu bioaccumulation rates calculated for lettuce, cress, dill and radish were surpassed maximum permissible levels (MPL). However, the bioaccumulation ranges calculated for lettuce, cress, dill and radish respectively were; lead (3.01-6.72mg/ kg/ dwt), (3.03-6.52mg/ kg/ dwt), (0.48-2.74mg/ kg/ dwt) and (0.41-3.00mg/ kg/ dwt); nickel (1.01-3.92mg/ kg/ dwt), (4.03-7.99mg/ kg/ dwt), (0.37-3.98mg/ kg/ dwt) and (1.00-3.95mg/ kg/ dwt) and copper (8.02-15.26mg/ kg/ dwt), (7.20-13.62mg/ kg/ dwt),(6.35-10.37mg/ kg/ dwt), (2.01-5.94mg/ kg/ dwt). The studied vegetables were showed different modes concerning heavy metal accumulation rates.