Assessment of internal exposures from ingestion of geophagic materials found in some parts of Kenya

Abstract

An assessment of the radiological impact of Geophagia deliberate ingestion of soil. was carried out in this study Samples of the most widely used geophagic materials were collected from three regional locations in Kenya. The radioactive levels were determined using gamma rav spectroscopy. and the elemental concentrations were measured using the \:-Ra: Fluorescence (XRF) spectroscopy. The potential internal doses due to the ingestion of these geophagic materials were estimated using calculations based on biokineric and dosimetric models. The \:RF results show that Iron is the most abundant element in all the samples. The other elements that were also present in significant concentrations include Manganese. Titanium. Calcium. and Potassium. Bur there are no observable correlations between elemental composition of samples and sampling location. The average active concentrations of Ra. Th and K in the samples are also within the normal ranges reported elsewhere. Bur the levels were generally lower in the samples from locations in the Siaya district of Nyanza province compared to the other two regions. i.e. Maragua district in the Central province and Nakuru in the Rift valley province. In the dose calculations. only the internal doses to the Castro-Intestinal (GI) tract. comprising the stomach and the intestines were considered. The specific effective dose per unit intake per unit time was calculated. The highest average internal dose of.3.45 x 10·' uSv per gram per day v"35 obtained tor samples from Kenol -quarrv in Maragua district. Central province. and the least value of 5.85 x 10- u Sx per gram per da: \\35 obtained for samples from Mbinga in Siayadistrict Nyanza province. The radiological significance of these findings is discussed in this report.