Abstract

Vegetable cultivation at urban peripherals is gaining ground due to the quest to feed an ever-increasing urban populace. However, the extensive use of agrochemicals in such gardens often leads to heavy metal contamination, with consequences for soil quality and human health. In order to safeguard human health and protect the environment, this study evaluated the contamination levels of per-urban vegetable garden soils with Cd, Cr, Cu, Pb, Ni, Co, and Zn after long-term use of agrochemicals. Soil samples were analyzed for their physicochemical parameters using standard methods, and their heavy metal content was analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy. The data were subjected to descriptive and inferential statistics using Microsoft Excel 2019, R programming, and ARCGIS for mapping. The soil recorded a low pH (4.5-5.8). The organic matter content ranged from medium to very high (3.08-7.52%). The cation exchange capacity varied from very low to low (ranging from 14.48-22.06 cmol/kg). Soil textures ranged from clay loam to loamy to sandy loam. The heavy metal concentrations were significantly higher than the maximum acceptable limits. The soils varied from unpolluted to moderately polluted, with contamination factors ranging from 9.37E-05 to 5.136 mg/kg. The pollution load indices were generally less than 1. The contamination degree and potential ecological risk index indicated slight to moderate pollution levels. Cobalt was identified as the heavy metal of major concern. The study highlighted minimal environmental and health risks, but with increasing trends of agrochemical use in vegetable cultivation, considerable efforts should be made to reduce agrochemical use and protect soil and human health, including the use of organic manure.

Key words: Soil heavy metals, vegetable-cultivation, pollution level, human health, sustainable management.