Long-lived Gamma-Emitting Radionuclides in Commonly Consumed Imported Coffee Brands in Lagos and the Total Committed Effective Dose using a High Purity Germanium Detector

Abstract

In public opinion, most of the imported food products are associated with several health risks relative to their origin. This study was set out to evaluate the long-lived gamma-emitting radionuclides in coffee brands imported from different countries, with steps taken towards assessing the harmfulness due to the level of activity in the each sample. The commonly consumed brands were selected based on a mixed sampling method. The samples were prepared accordingly for gamma analysis and analyzed through hyper pure germanium gamma spectrometry technique. The outcome of the study based on the counting statistics recorded the minimum activity concentrations value of 0.10 ± 0.04 Bq kg^-1, 0.34 ± 0.04 Bq kg^-1 and 0.34 ± 0.04 Bq kg^-1, maximum activity concentrations value 0.41 ± 0.08 Bq kg^-1, 2.39 ± 0.32 Bq kg^-1 and 985.32 ± 52.25 Bq kg^-1, and all-sample mean of (±SD) 0.19 ± 0.05 Bq kg^-1, 1.31 ± 0.15 Bq kg^-1 and 877.49 ± 46.54 Bq kg^-1 respectively for ²³⁸U, ²³²Th and ⁴⁰K. While the activity concentrations of ²³⁸U and ²³²Th are well below the acceptable limit, the activity concentrations of ⁴⁰K is dominant and significantly higher than the threshold value irrespective of the origin. The current findings also indicate that activity concentrationsfor²³⁸U and ²³²Th lie within the data for other food samples, but that of ⁴⁰K is clearly above the values in other food samples. Potassium, one of the vital micromolecules in the body, is essentially regulated under normal condition in healthy human. In spite of its higher value, ⁴⁰K is disregarded as a contributor to the ELCR and was not accounted for in this study. This study presents mortality probability of 6 in 100,000,000.