IMPACTS OF CANAL WATER ON SOIL QUALITY, TOMATOES AND PUBLIC HEALTH IN DISTRICT SWABI

Abstract

The current study evaluated the impacts of using contaminated canal water for irrigation on health and the environment in District Swabi, Khyber Pakhtunkhwa. The study determined the quality of canal water, its impacts on soil characteristics, accumulation of heavy metals in tomatoes, and health risks to humans based on heavy metal concentrations. Water, soil, and tomato samples were collected from a geographical site where the main use of water is for agriculture and heavy metal concentrations were determined for Cadmium, Lead, Chromium, and Nickel, using standard laboratory methods. In soil samples, Cd ranged from 2.9 to 4.3 mg/kg, Cr 85 to 135 mg/kg, Pb 87 to 142 mg/kg, and Ni from 40 to 68 mg/kg and most were above World health organization Standards. For canal water, a high level of metals was observed above the required limits suggested by the World Health Organization as; Cadmium was up to 0.174 mg/L (Worl Health Organization limit: 0.1 mg/L), Chromium was up to 1.378 mg/L (1.0 mg/L), Lead was up to 5.13 mg/L (0.01 mg/L), and Nickel was up to 3.887 mg/L (1.0 mg/L). Contaminated irrigation water affected metal uptake in tomato fruits directly with Cd (0.01-0.6 mg/kg), Cr (0.01-0.4 mg/kg), Pb (0.2-0.9 mg/kg) and Ni (most were safe levels, only a few cases were semi- safe). Some tomato samples were above the WHO food safety limits, with the samples of Cd, Cr, and Pb being the main exceedances. This study demonstrates that farmers are contaminating soil and food crops by using polluted canal water for irrigation. The current study suggests that contamination by heavy metals has negative impacts on the environment and humans. These studies show immediate and continuous action must be taken to monitor and evaluate regulations indicated for soil health, food safety and human health in the area.