Distribution of natural radioactivity around mechanized and non-mechanized mining regions

Abstract

This study was conducted to assess the radiological impacts of mining activities in mechanized and non-mechanized mining sites in order to build up database records for non-nuclear industries. Measurements of 226Ra, 226Th and 40K in 50 soil samples collected from these sites were carried out using gamma spectrometry system. The investigations showed that the highest concentrations of these radionuclides were 32, 37 and 648 Bq/kg, respectively . The average values in the mechanized region were 16 ± 7, 22 ± 9 and 366 ± 148 Bq/kg, respectively, while in non-mechanized region they were 9 ± 4, 12 ± 6 and 111 ± 68 Bq/kg, respectively. Spearman’s rank correlation test resulted in significant correlations (at 0.01 level) between 226Ra and 232Th (0.6) and 40K (0.8) in the mechanized region, while 232Th correlated with 40K (0.445) in the non-mechanized region. At 0.05 level, only 232Th is correlated with 40K in mechanized area (0.58). Between the two groups, only 40K in the mechanized area showed significant correlation to 232Th in the non-mechanized area (0.497) at 0.05 level. The 226Ra/232Th ratios were 0.88 ± 0.66 and 0.77 ± 0.23 in the two regions, while 226Ra/40K ratios were much lower than natural. This is attributed to weathering and metrological conditions rather than mining activity. Some radiological parameters were assessed displayed in general, significantly low values when compared with average global and recommended values. It can be concluded that both mechanized mining and non-mechanized mining do not significantly alter the levels of natural radioactive elements and do not give rise to a significant radiation exposure for the mining workers or population.