地理情報学と地球統計学: 概要

ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND LOCAL GEOLOGY OF BUILDING MATERIALS USED FOR THE CONSTRUCTION OF MUD HOUSES IN KANKE AREA, PLATEAU STATE, NIGERIA.

NANSAK. B RIMVEN

 An assessment of outdoor radiation in parts of Kanke Local Government Area of Plateau State Nigeria was carried out using a Portable Handheld Gamma ray Spectrometer/Scintillometer (RS-230). Readings of radiation counts of Uranium, Thorium, Potassium and distribution of dose rates (DR) were taken from rocks and soils, which are the main building material used in the construction of mud houses in the study area. Samples were also taken to ascertain elemental compositions and show co-relation of the elements Uranium, Thorium and Potassium to radiation. From the results, the highest values observed in the activity concentration of Uranium, Potassium, and Thorium for rock were 2325 Bq kg⁻¹ (K), while the lowest values were 0.000 for all the three elements. The highest values observed for the activity concentration for soil were 2232 Bq kg⁻¹   (K), while the lowest values were 20.3253 Bq kg^{−1 (}Th). The potential radiological hazards were assessed by calculating the estimated Absorbed Dose Rate (D_R), Annual Effective Dose Rate (H_R), Radium Equivalent Activity (Ra_eq) and External Radiation Hazard (H_EX). These parameters were all calculated and compared with other works on the basement complex rocks within and outside Nigeria and the results obtained were found to fall within the acceptable limits of 1mSv/yr, UNSCEAR (2000), IAEA, NEA-OECD and WHO.