Health risk assessment of potassium bromate in bread in Ghana

Potassium bromate (KBrO₃) is an oxidizing agent added to flour to improve bread quality. However, KBrO₃ is nephrotoxic, and a class B carcinogen banned in most countries, including Ghana.

This study aimed to determine the residual KBrO₃ concentration in bread and to estimate the chemical and carcinogenic risk that is associated with the consumption of these breads in Ghana.

A total of 285 samples of bread, consisting of 97 tea breads, 95 sugar breads, and 93 butter breads were randomly sampled from bakeries across ten regions of Ghana for this study. The bromate contents were qualitatively and quantitatively determined spectrophotometrically at 515 nm, based on the redox reaction between KBrO₃ and promethazine. The change in colour from colourless to pink indicated the presence of KBrO₃ in the sample. The data were analyzed with Microsoft Excel 365 Apps for Enterprise and GraphPad Prism and the map was plotted with QGIS.

Out of the 285 bread samples analyzed, 12.28% (35/285) tested positive for KBrO₃ with concentrations ranging from 0.46 to 26.67 μg/g (mean 6.13 μg/g). This exceeded the permissible dose (0.02 μg/g) by 23-1334 times, respectively. Except Ashanti and Volta regions, all the other 8 regions had at least one bread type testing positive for KBrO₃. There was no statistically significant difference in the concentration of KBrO₃ between the bread types analyzed at p < 0.05. The hazard ratio ranged from 0.166 to 0.435 and the chronic hazard quotient ranged from 0.0037 to 0.00141.

Breads from 8 regions of Ghana tested positive for KBrO_3, but their concentrations may not pose chemical or carcinogenic risks after regular consumption.