Assessment of heavy metal contaminations in irrigation water, soils, and onions in the Isser and Zemmouri Regions, Algeria

This study investigates heavy metal contamination in irrigation water, soil, and onion (Allium cepa L.) samples from the Isser and Zemmouri regions of Boumerdes, Algeria, to assess potential health risks from consuming these vegetables. The analysis focused on both essential and toxic heavy metals, including iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd), chromium (Cr), lead (Pb), and nickel (Ni). Atomic Absorption Spectroscopy (AAS) was employed for accurate quantification, and results were compared with FAO/WHO 2001 standards. Elevated copper (0.72 mg/L) and zinc (0.19 mg/L) levels were detected in Isser’s irrigation water, while Zemmouri’s water contained near-threshold concentrations of nickel (0.18 mg/L), chromium (0.09 mg/L), and copper (0.14 mg/L). Soil contamination was observed at both sites, with Isser showing high Cu (68.41 mg/kg), Zn (62.12 mg/kg), and Pb (71.63 mg/kg) levels, while Zemmouri exceeded limits for Pb (64.32 mg/kg) and Ni (11.21 mg/kg). In onion bulbs, Isser showed elevated chromium (3.1 mg/kg) and lead (0.31 mg/kg), while Zemmouri exhibited high zinc (11.34 mg/kg) and iron (43.76 mg/kg) levels in leaves. These findings indicate significant health risks associated with onion consumption from these regions, highlighting the need for improved monitoring and management of water quality and agricultural practices.