Browsing by Author "Odumo, Benjamin O."

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    Natural Radioactivity Levels and Radiological Risk Assessment in Locally Grown Maize and Beans from Bungoma County
    (Open Access Library Journal, 2024-12-30) Tsimbasi, Stanley C.; Makokha, John Wanjala; Odumo, Benjamin O.
    This study investigated the concentration of 226Ra, 232Th, and 40K in maize (Zeamays) and beans (Phaseolus vulgaris), the common cereals and pulses available in Bungoma County. Eighteen representative samples were collected from the study area and analyzed using a Thallium-activated Sodium Iodide NaI (TI) scintillation detector. The average activity concentration of 226Ra, 232Th, and 40K in maize were found to be 20.9 ± 7.19 Bq/kg, 54 ± 21.15 Bq/kg, and 161 ± 76.84 Bq/kg, while in beans, these values were 18.4 ± 4.03 Bq/kg, 43 ± 15.51 Bq/kg and 195 ± 132.48 Bq/kg respectively. The mean absorbed dose rates were 49 ±2.45 nGy/h and 43 ± 2.15 nGy/h for maize and beans respectively which were lower than the admissible dose standard of 1500 nGy/h. The average annual effective ingestion dose (AEID) in maize and beans were 1.240 mSv/y and 0.263 mSv/y respectively. The average AEID values in maize were above the limit of 1mSv/y for the general public, as the International Commission on Radiological Protection (ICRP) recommended. This shows that there is an increased health risk for the whole body of an individual due to the intake of maize with higher AEID. While the AEID in maize suggests an elevated health risk for consumers due to whole-body radiation exposure, the overall radiological risk posed by beans and other consumption in the region remains minimal and within international safety limits hence poses no significant risk to the consumers and the general populace of Bungoma County.
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    Radiological Assessment of Gamma Ray Index and Excessive Lifetime Cancer Risk in Locally Grown Maize and Beans in Bungoma County, Kenya
    (Voice of the Publisher, 2025-06-09) Tsimbasi, Stanley C.; Makokha, John Wanjala; Odumo, Benjamin O.
    Radionuclides ingested through food consumption may contribute significantly to the average irradiation of different organs in the body. This study focused on radiological hazard indices by consuming maize (Zea mays) and beans (Phaseolus vulgaris) locally grown in Bungoma County. The activity concentration of 226Ra, 232Th, and 40K in eighteen representative samples was determined by gammaray spectrometry technique using a Sodium Iodide (NaI (TI)) scintillation detector, and the hazard indices were determined. The average activity concentration of 226Ra, 232Th, and 40K in maize and beans were 20.9 ± 7.2 Bq/kg, 54 ± 21.2 Bq/kg, 161.0 ± 76.8 Bq/kg, and 18.4 ± 4.0 Bq/kg, 43.0 ± 15.5 Bq/kg, 195.0 ± 132.5 Bq/kg respectively. Average AEID values for maize and beans were 1.31 mSv/year and 0.26 mSv/year, respectively. For maize, the gamma ray index is 0.7 ± 0.206, and excessive lifetime cancer risk is 4.89 × 10−8. For beans, the gammaray index is 0.6 ± 0.2, and excessive lifetime cancer risk is 1.00 × 10−8. Excessive lifetime cancer risks associated with 226Ra, 232Th, and 40K were all within the internationally recommended limits of 10⁻3. The average gamma representative indices for both maize and beans were below unity, according to International Commission on Radiological Protection ICRP guidelines, indicating that their consumption poses minimal radiological risk to the residents of Bungoma County.