Abstract:
The use of waste or untreated water for irrigation purposes particularly in developing nations where fresh water supplies are rare, is a common practice. This study examines the impact of using untreated sewage water for irrigation in selected sites in Islamabad, where fresh water is scarce. It focuses on the contamination of soil, vegetables, and water by toxic heavy metals, posing significant risks to human health. Samples of irrigation water, soil, and vegetables were collected from sewage water irrigation (SWI) and groundwater irrigation (GWI) zones from surrounding of Islamabad. The analysis targeted heavy metals like Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Cobalt (Co), Nickel (Ni), Lead (Pb), and Zinc (Zn). Results show that sewage water and the soil irrigated with it were highly polluted, with As and Cd levels being particularly alarming. In vegetables from the SWI zone, arsenic concentration followed the order: China cabbage (3.26 mg/kg) > Mint (2.41 mg/kg) > Tomato (2.3 mg/kg) > Tinda (0.68 mg/kg), while cadmium concentrations were highest in Cauliflower (9.43 mg/kg), followed by China cabbage (2.56 mg/kg) and other vegetables. These levels exceed permissible limits, posing significant health risks. In contrast, vegetables from the GWI zone were comparatively safer. The study highlights the urgent need for continuous monitoring of heavy metal levels in water, soil, and crops in the farmlands across Islamabad to prevent harmful accumulation in the food chain. It provides critical insights into heavy metal contamination, informing policymakers and stakeholders on sustainable environmental management and agricultural practices to protect public health and food security in Islamabad.
