Journal Articles

Permanent URI for this collectionhttp://erepository.kibu.ac.ke/handle/123456789/9624

Browse

Browsing Journal Articles by Subject "Absorbed Dose Rate"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Radiological Risk Assessment of 238u, 232th And 40k in the Top Soils of Ahero Paddy Fields of Kisumu County, Kenya
    (Journal of Engineering and Technology for Industrial Applications, 2022-08-22) Mukanda, Kere Wanyama; Waswa, Michael Nakitare; Ouma, Linda Immaculate
    A radiological risk assessment of 238U, 232Th and 40K in the top soils of Ahero paddy fields of Kisumu County has been measured using NaI(TI) gamma ray spectroscopy. A total of 17 samples were collected at a depth of 15 - 20 cm and measured for activity concentrations of three radionuclides which were used to calculate the absorbed dose rates and Annual effective dose rates of the samples. Samples were collected from fields at various stages of farming process i.e., four (4) weeks after transplanting (field 1), during transplanting (field 2), after harvesting and land ploughed (field 3) and a control field (field 4) where rice farming had not been done for 2 years. The average activity concentrations for the three radionuclides for field 1 were 32.63 ± 1.63 Bq/kg for 238U, 104.69 ± 5.20 Bq/kg for 232Th and 75.00 ± 3.2 6 Bq/kg for 40K. The average activity concentrations of the radionuclides from field 2 were 16.97 ± 0.84 Bq/kg, 68.03 ± 3.40 Bq/kg and 70.31 ± 3.51 Bq/kg for 238U, 232Th and 40K respectively. The average activity concentrations of the radionuclides from field 3 (post harvesting) were 28.92 ± 1.44 Bq/kg, 91.73 ± 4.58 Bq/kg and 122.60 ± 6.13 Bq/kg for 238U, 232Th and 40K respectively. The average activity concentrations of the radionuclides were 29.74 ± 1.48 Bq/kg, 121.11 ± 6.05 Bq/kg and 87.51 ± 4.37 Bq/kg for 238U, 232Th and 40K respectively. The average Absorbed Dose Rates were 81.50 ± 4.07 nGy/h for field 1, 52.59 ± 2.62 nGy/h for field 2; 74.68 ± 3.73 nGy/h for field 3 and 91.79 ± 4.59 nGy/h for field 4. The values were below the permissible limit of 1500 nGy/h, thus the radiological risk associated with the top soils of the Ahero Paddy fields of Kisumu County, Kenya is insignificant.