Measurement of Heavy Metals in Bread with an Emphasis on the Risk Assessment of Aluminum

Document Type : Research Paper


1 PhD Student of Animal and Poultry Health and Nutrition, Department of Basic Sciences, Toxicology and Animal Poisoning Research Center, Faculty of Veterinary Medicine, University of Tehran (FVM-UT), Tehran, Iran.

2 Professor of Toxicology, Division of Toxicology, Department of Comparative Bioscience, Faculty of Veterinary Medicine, University of Tehran (FVM-UT), Tehran, Iran.

3 PhD Student of Toxicology, Department of Comparative Bioscience, Faculty of Veterinary Medicine, University of Tehran (FVM-UT), Tehran, Iran.


Introduction: Humans are exposed to aluminum (Al) and other heavy metals through various sources. Scientists have long investigated the effects of Al and heavy metals on human health, reporting a correlation between Al concentrations and health issues such as Alzheimer’s diseases and cancer. Therefore, a risk analysis study is required to assess the risk of non-cancerous diseases. The present study aimed to measure heavy metals in bread with an emphasis on the risk assessment of Al. Methods: Various types of flatbread, cakes, and muffins were randomly collected in Tehran, Iran. The samples were prepared based on the modified AOAC official method. Subsequently, test solutions were analyzed for Al, Pb, Hg, Ni, As, Cd, Co, Cr, and Cu via inductively-coupled plasma/optical emission spectrophotometry (ICP-OES). Significant differences between the bread sample groups were determined using one-way analysis of variance (ANOVA) and Duncan’s least square difference (LSD) test. Results: We calculated the concentration, daily intake (DI), national theoretical maximum daily intake (NTMDI), and the hazard quotient (HQ) of Al in Iran. The lowest concentration of Al was observed in Sangak bread, and the highest level was detected in Taftan bread. In addition, the highest Al concentration was observed in cakes (mean: 40.44). The DI of Al was estimated at 0.26 mg/kg, and the NTMDI for adults was 0.005. The HQ of Al in all the bread samples was less than one. Conclusion: According to the results, the mean acceptable daily intake of Al was 92% of the provisional tolerable daily intake, and the HQ was less than one in the studied bread samples. Therefore, no risk of non-cancer diseases was observed due to the consumption of the bread samples.


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