Assessment of Lead, Cadmium, Iron, and Zinc Contamination in Wheat Grains From Multan District: Sources, Health Risk Evaluation, and Potential Implications

Background: Wheat (Triticum spp.) is a staple food crop cultivated globally and consumed by over one-third of the world’s population. In Pakistan, it remains a primary dietary source of macronutrients and essential trace minerals such as iron and zinc. However, the rise of heavy metal contamination—mainly from industrial runoff, wastewater irrigation, vehicular emissions, and agrochemicals—has raised serious concerns about food safety, particularly with respect to cadmium (Cd), lead (Pb), iron (Fe), and zinc (Zn). Objective: This study aimed to quantify the concentration of selected heavy metals in commonly grown wheat varieties from Multan district, Pakistan, and assess potential public health risks associated with their consumption. Methods: A total of 25 wheat grain samples representing five different varieties (A–E) were collected from local farms, markets, and storage facilities. Parallel soil and irrigation water samples were obtained from corresponding fields. All samples were subjected to wet acid digestion and analyzed using Flame Atomic Absorption Spectrophotometry (FAAS). Statistical comparisons were conducted using ANOVA and homogeneous grouping to evaluate inter-varietal metal differences. Results: Lead (Pb) concentration ranged from 0.0320 ± 0.0261 to 0.0376 ± 0.0355 mg/kg, with significant variation across varieties (p < 0.05). Zinc (Zn) ranged from 0.0557 ± 0.0283 to 0.1153 ± 0.0546 mg/kg and also showed significant varietal differences. Cadmium (Cd) ranged between 0.0338 ± 0.0070 and 0.0391 ± 0.0060 mg/kg, and iron (Fe) varied from 0.0396 ± 0.0052 to 0.0850 ± 0.0041 mg/kg; both showed statistically non-significant differences (p > 0.05). All concentrations remained below international safety thresholds but indicated potential cumulative exposure risk. Conclusion: The study highlights low but detectable levels of heavy metals in wheat grains from Multan, especially Pb and Zn. It recommends proactive measures such as using clean irrigation sources, soil monitoring, phytoremediation practices, and safe grain storage to reduce contamination. These findings support the promotion of sustainable agricultural practices and informed policymaking to protect food safety and public health.