Assessment of levels of naturally occuring radionuclides at iron mining and processing sites in the Midlands Province of Zimbabwe.

Abstract

Mining and mineral operations have been associated with exposures of Naturally occurring radioactive materials. A study was carried out to assess the activity concentration of naturally occurring radionuclides in iron mining, processing and waste materials by means of high resolution gamma ray spectrometry using a 109 HPGe detector. A total of 12 sampling points were sampled for the Buchwa’s Ripple creek Mine, Buchwa Limestone mine and ZISCO Steelworks damp site. The samples were measured in the laboratory with respect to their gamma radioactivity for a counting time of 60000 seconds each. From the obtained spectra, activity concentrations were determined. The mean activity concentrations of 238U, 232Th, 226Ra, 210Pb and 40K in the soil samples were, 220.95, 32.99, 181.60, 112.99 and 276.24 Bq/kg respectively. The study also highlighted the potential hazards of alpha, beta and gamma emissions on human body and their mechanisms for inhalation and ingestion. The total effective dose was 0.4275 mSv per annum. The results in this study compared well with the average worldwide average values. The results indicate an insignificant exposure of public to technologically enhanced NORM.