HEALTH RISK ASSESSMENT OF HEAVY METALS DUE TO UNTREATED WASTEWATER IRRIGATED VEGETABLES

Abstract

Immense amount of wastewater is used for irrigation of vegetables and crops in order to cope with water scarcity issues in Pakistan. Wastewater is highly contaminated due to the disposal of untreated industrial wastewater into the main drains. Therefore, crops and vegetables have concentrations of heavy metals and other contaminants. The study was conducted at Chokera wastewater treatment plant in district Faisalabad, where wastewater is used for irrigation of vegetables. Samples of wastewater were collected from the drain during different time interval to find out variations in wastewater characteristics. Samples of irrigation wastewater and cultivated vegetables by wastewater were collected and investigated to check the Arsenic concentrations in vegetables. Soil samples and groundwater samples from the nearby vicinity have been taken so as to investigate the impact of wastewater characteristics which is being used for irrigation purposes. Furthermore, health risk assessment due to arsenic was conducted because consumption of wastewater irrigated vegetables. Results of selected vegetables shown that the edible portions of vegetables had average concentrations of Ni, Pb, Cd and Cr as 30.14, 27.49, 27.67 and 7.56 mg kg-1, respectively. All the water samples were alkaline. The mean concentrations of Ni, Pb, Cd and Cr in leaves samples were 30.78, 15.58, 12.37 and 3.74 mg kg-1, respectively. Waste water without treatment is not fit for irrigation to the vegetables.