Risk-Informed Assessment of Heavy Metal Exposure Through Wheat Flour Consumption in Northern Iraq

Wheat flour is a staple food with high consumption rates, making it a potential pathway for dietary exposure to heavy metals. This screening-level study evaluated the concentrations of selected heavy metals in commercially available wheat flour marketed in Erbil, northern Iraq, and assessed associated dietary exposure and noncarcinogenic health risks. Twenty wheat flour samples of domestic and imported origin were analyzed for arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), and nickel (Ni) using inductively coupled plasma-optical emission spectrometry (ICP-OES). Mean concentrations of arsenic (As) and lead (Pb) exceeded Codex guideline values in a substantial proportion of samples, whereas nickel (Ni) exceeded commonly referenced benchmark values reported in international risk assessments. Dietary exposure was assessed using estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) approaches for both adult and child populations. For adults, HQ values for individual metals were below unity, and the cumulative HI (HI = 0.598) indicated no significant noncarcinogenic risk. In contrast, higher EDI and HQ values were observed for children, and the cumulative HI (HI = 1.675) exceeded unity, suggesting a potential health concern for younger populations with higher relative intake. These findings highlight the importance of exposure-based risk assessment for staple foods and underscore the need for continued monitoring of wheat flour to protect vulnerable population groups.