Background: Bread is regarded as one of the most predominant foods consumed among the poor. It is seen as the largest contributor to radiation doses received by the human body. Therefore, this study was carried out to evaluate the potential health implications due to natural radioactivity and heavy metals in bread samples commonly consumed in Apata, Ibadan South-West Local Government Area of Oyo State, Nigeria.

Materials and Methods: Gamma spectrometry (HpGe) was used to evaluate the potential health implications due to natural radioactivity while the heavy metals were determined using atomic absorption spectrophotometry. Relevant radiological hazard parameters and health risks assessments due to heavy metal consumption were also evaluated.

Results: Results of this study showed that the mean activity concentrations of 226Ra, 232Th and 40K as 31.57 3.61, 11.46  0.68 and 349.45  18.25 Bqkg-1 respectively. Estimation of the radiological risk parameters showed: average annual committed dose 0.04 – 0.12, absorbed dose 19.32 – 49.32, annual gonadal dose equivalent 144.59 - 255.16, radium equivalent 40.35 - 74.86 and internal hazard index 0.10 – 0.44. These values were lower than the world average values of 1.0 , , 300 , 370  and unity respectively for ingestion of natural radionuclides provided by the United Nations Committee on the effects of Atomic Radiation for any individual. Results of the heavy metal contents (mg/kg) showed: Lead BDL, Iron 25.01 – 103.89, Zinc 2.26 – 7.39, Copper 3.56 – 3.78 and Cadmium BDL. Results of health risks due to heavy metals in adult populace showed: average daily intake 0.004 – 0.647 mg/person/day, health risk index 0.040 – 7.189 and target hazard quotient 0.0006 – 0.3767. All the evaluated potential health risk parameters of the adult populace due to the heavy metal intake from consumption of the bread sample were lower than the permissible limits (apart from occurrences in THQ-target hazard quotient - values).

Conclusion: The results suggested that consumption of bread samples in the study arears may not pose significant health risk to adult populace. However, continuous consumption may pose toxicological risk due to the accumulation in the body. Hence, monitoring of the natural radionuclides and heavy metals in bread samples and other foodstuffs should be carried out for long term ingestion. This investigation may serve as a baseline study for further researches on the subject.

Keywords: Natural radioactivity, gamma spectrometry, atomic absorption spectrometry, heavy metals, radiological hazard parameters, health risk assessments