Comparative Evaluation of Heavy Metal Uptake in Soils and Crops Irrigated with Canal and Wastewater in Lahore, Pakistan

Heavy Metal Uptake in Soils and Crops Irrigated with Canal and Wastewater

Abstract

This research investigates the accumulation of heavy metals in soils and different number of crops such as spinach, rice, potatoes, and cucumbers irrigated with canal and municipal wastewater. As freshwater reservoirs decline, alternative irrigation sources such as wastewater are increasingly used, though they may contain contagious levels of metals like arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb). In this comparative analysis, soil and crop sample including various crops (potatoes, spinach, cucumbers, and rice) were collected from both canal- and wastewater-irrigated fields and characterized by using Atomic Absorption Spectroscopy (AAS). Arsenic was found in the highest concentrations (1.5-5 ppm), particularly in wastewater-irrigated crops, often exceeding optimum consumption limits. Chromium was present at moderate levels (0.7-1.9 ppm), while lead and cadmium (<0.1 ppm) appeared in lower but still were present at alarming rate. These outcomes signify the risks posed by wastewater irrigation to food safety and human health. Furthermore, this study emphasizes the urgent need for regular monitoring of irrigation sources, execution of remediation strategies especially for arsenic and stricter regulatory supervision. Promoting safe and accessible irrigation practices is essential to protect public health and ensure long-term agricultural yield.