Radiological Assessment of Gamma Ray Index and Excessive Lifetime Cancer Risk in Locally Grown Maize and Beans in Bungoma County, Kenya

Abstract

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.