Food Safety Risks from Heavy Metals and Pesticide Residues in Cauliflower (Brassica oleracea) from a Subtropical Region of Pakistan

<title>Abstract</title> <p>Heavy metal contamination and pesticide residues in vegetables irrigated with wastewater pose serious risks to food safety and human health. This study evaluated the concentrations of selected heavy metals, including copper (Cu), lead (Pb), chromium (Cr), cadmium (Cd), and cobalt (Co), along with pesticide residues of chlorpyrifos, imidacloprid, carbofuran, profenofos, and lambda-cyhalothrin in cauliflower (Brassica oleracea) cultivated under wastewater irrigation in Gujranwala, Pakistan. Heavy metal concentrations in cauliflower, soil, and wastewater were determined using Flame Atomic Absorption Spectroscopy (FAAS), while pesticide residues were analyzed through High Performance Thin Layer Chromatography (HPTLC). The results revealed elevated concentrations of Cd (0.253 mg/kg), Pb (0.350 mg/kg), and Co (0.197 mg/kg) in cauliflower curds, exceeding permissible limits. Soil samples also showed higher Cd accumulation (0.403 mg/kg), whereas wastewater samples contained elevated levels of Pb, Co, Cr, and Cd beyond recommended standards. Statistical analysis indicated significant variations among heavy metals, particularly Cr and Co. Bio-concentration ratio analysis demonstrated greater accumulation of Cd and Co in curds and Cu in leaves. Chlorpyrifos residue (0.0634 mg/kg) exceeded the maximum residue limit, highlighting potential health hazards and the need for continuous monitoring of wastewater-irrigated vegetables.</p>