Assessment of Radiation Levels and Geochemical Factors in Iraqi Soil

Radiation exposure related human hazards and environmental pollution caused by the natural and manmade radioactive materials needs inhibition. An accurate evaluation of the radiation levels and geochemical factors of soil play a vital role. In this perception, γ-ray spectroscopy with NaI (Tl) luminescence detector was used to assess the natural radioactivity level and associated radiological risk due to contaminated surface soil (33 samples) collected from the Waist province of Iraq. Compared to the stipulated global average, about 64% and 15% of the samples showed higher radioactivity concentration of 226Ra and 40K, respectively, whereas for 232Th it was lower. Furthermore, the statistical guides of the geo-accumulation and contamination factors were used to calculate the pollution levels in the soil samples. The geochemical factors for some polluting heavy metals (Ge, Se, Ag, Sn, Sb, Te, I, Ce, Hf, W, Hg, Ti, and Bi) in the samples revealed wide variation. The contamination factor and I-Geo-accumulation catalogues of the samples exhibited the pollution level fluctuations from very high (Hg of 1.88 ppm) to very low (W of 1.33 ppm, U of 1.87 ppm, Sn of 3.8 ppm, Sb of 2.99 ppm, Ti of 0.66 ppm and Ag of 1.92 ppm, Bi of 1 ppm) to moderate Se of 0.53 ppm, Hf of 1.81 ppm and I of 3.19 ppm). It was asserted that the observed intense adsorption of some specific metals on the surface soils was due to the natural sources in the clays and heavy minerals originated from the carbonates. Such heavy elements could move into the minerals structure of the surface soils from the anthropogenic urban wastes, agricultural and industrial activities.