Radionuclide Analysis of Locally Processed Snuff Tobacco Consumed in Benue State

Abstract

Radionuclide analysis of locally processed snuff tobacco consumed in Benue state was carried out using a lead-shielded NaI(TI) detector crystal (Model No. 802 series, Canberra Inc.) coupled to a Canberra series 10 plus Multichannel Analyzer (MCA) (Model No. 1104) through a preamplifier. The detector measured the radionuclide activity concentrations of locally processed snuff samples collected from the selected Local Government Areas (LGAs) of the state. The results showed that the average values of activity concentrations (Bqkg^-1) of ⁴⁰K, ²³⁸U and ²³²Th in the analyzed snuff samples were 1292.86 ± 63.73, 22.57 ± 2.65 and 8.26 ± 0.48 Bqkg^‑1 respectively. In addition, a control sample (an additives-free snuff) was used. The activity concentrations of ⁴⁰K, ²³⁸U and ²³²Th in the additives-free snuff sample were 617.73 ± 30.93 Bqkg^-1, 26.49 ± 3.05 Bqkg^-1 and 4.06 ± 0.23 Bqkg^-1 respectively, whereas the activity concentrations of a snuff sample made with additives (S5) that shared tobacco leaves of same source (plants) with the additives-free snuff (A5) during their processing were 565.05 ± 28.14 Bqkg^-1, 28.86 ±3.61 Bqkg^-1 and 4.28 ± 0.25 Bqkg^-1 for ⁴⁰K, ²³⁸U and ²³²Th respectively.  Meanwhile, the mean value of radium equivalent activity obtained for the snuff products was 133.93 Bqkg^‑1 and thus found to be lower than the UNSCEAR recommended limit of 370 Bqkg^‑1.  The estimated average value of annual effective dose (µSvy^-1) was 369.14 for inhaling 1 wrap of snuff daily, and was also found to be lower than the UNSCEAR recommended limit of 1260 µSvy^-1. However, consuming 4 wraps of snuff daily would result to an annual effective dose of 1476.56 µsvy^-1. This value was therefore found to be higher than the recommended limit of 1260 µSvy^-1. Furthermore, the estimated excess lifetime cancer risk averaged 1.29×10^-3 for inhaling 1 wrap of snuff daily and was thus seen to...