Assessment of Potassium Bromate Levels and Dietary Health Risk in Commonly Consumed Breads in Ijebu-Ode, Ogun State, Nigeria

Abstract

The continued use of potassium bromate as a dough improver in bread production is often driven by its technological advantages, including enhanced loaf volume and improved texture; however, its potential adverse health effects remain a major public health concern. In addition, contamination of bread with heavy metals may further compromise consumer safety. This study therefore quantified potassium bromate and selected heavy metals (Pb, Cd, Cr, Ni, Fe, and Zn) in commercial bread samples and evaluated associated dietary risks. Potassium bromate concentrations ranged from 1.52 ± 0.64 to 22.38 ± 0.98 mg/kg (mean: 9.35 ± 0.58 mg/kg), with 100% exceedance of the maximum permissible limit established by the World Health Organization and Food and Agriculture Organization. Heavy metals (mg/kg, mean ± SD) were: Pb (0.11 ± 0.052), Cd (0.04 ± 0.020), Cr (0.17 ± 0.060), Ni (0.12 ± 0.051), Fe (20.55 ± 5.42), and Zn (10.75 ± 2.70). Hazard Index values ranged from 0.062–0.197 (adults) and 0.291–0.923 (children). Although heavy metal exposure remained within non-carcinogenic safety thresholds (HI < 1), the widespread occurrence of potassium bromate classified as a possible human carcinogen by the International Agency for Research on Cancer indicates significant regulatory non-compliance and potential long-term health risks.