Activity Concentration and Associated Radiation Dose in Machinjoni Dumpsite in Trans-Nzoia County, Kenya.

Abstract

The activity concentration in Machinjoni dumpsite has been investigated. Activity concentration was measured using a 76 mm x76 mm NaI (Tl) detector using gamma ray spectrometry technique and various radiological parameters calculated to quantify the level of radiological hazardousness posed by the dumpsite on those interacting with the dumpsite. The mean activity concentration of 238U, 232Th and 40K in the dumpsite were 16±0.83 BqKg-1, 68±3.4 BqKg-1 and 60±3 BqKg-1 respectively. 232Th exceeded the permissible limit of 45 BqKg-1 while 238U and 40K were within permissible limits. The radiological hazard calculated in this study was absorbed dose rate. The calculated values of absorbed dose rate ranged from 29±1.45 to 140±7.03 nGyhr-1 with a mean of 51±2.56 nGh-1 and were lower than the world mean value of 84 nGhr-1. From the values it can be seen that there is significant radiation it parts of the dumpsite even though the mean values were all below permissible world values.