The natural radioactivity levels of Kirkuk oil field are studied using high resolution gamma rays spectrometry. For this reason, soil samples were collected from three sites in the Iraq North Oil Company: Baba Gurgur, Shurau and old process plant (Terkiz). The activity concentrations obtained for 238 U-series ( 226 Ra, 214 Pb, and 214 Bi), 232 Th-series ( 228 Ac, 212 Pb, and 208 Tl) and 40 K. The results have been compared with the worldwide average values.The radium equivalent activity (Ra eq ), the absorbed dose rate (D), the annual effective dose rate (AEDE), the external hazard (H ex ), the internal hazard (H in ) and Gamma radiation representative level Index (I g ) were also obtained and compared with the international recommended values.

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This study is based on agricultural soil samples which are collected along three traverses (A, B, C), near the gypsum quarries located near the village of Bajwan north of Kirkuk city, to conduct a geochemical analysis and determining some heavy elements (Co, Cr, Ni, Cu, Sr, Pb, Cd) levels in the surface and subsurface soil horizons, and to indicate the potential sources of contamination with these elements. Accordingly, 30 samples were collected (six samples from travers A, five samples from travers B, and four samples from travers C) from the soil for each of the surface and subsurface levels. The results showed that the average concentrations of most studied elements increased in the subsurface soil compared to the surface soil, as a result of the influence of different geological and environmental conditions on the distribution of these elements in different soil horizons. The concentrations of the studied elements (Co, Ni, Cd) are more than their natural concentrations when compared to the natural abundance of these elements in the earth's crust, which indicates an increase in the concentration of these elements in the soil as a result of the proximity of the study area to the oil industries activities, causing the emission of high concentrations of heavy elements. As well as the traffic density of vehicles, causing the release of high concentrations of some elements. The geo accumulation factor (Igeo) indicates that most of the soil samples within different horizons of most of the heavy elements are uncontaminated to moderately contaminated, and moderately contaminated for cadmium. Also, by calculating the RI and the environmental risk factor (Er), it was found that the relative content of cadmium in soil samples recorded a considerable potential ecological risk to a high potential ecological risk. This indicates high affinity of cadmium in the soil as its infiltration into the subsurface layers.

The chemical characterization study of the river sediment contributes to understanding the weathering and transportation trend and their impacts on the nature of the source rocks in the catchment region. Accordingly, sixteen samples of recent stream sediment were collected from the Balakian River, northern Iraq. The significant correlation coefficients for the major oxids (CaO, MgO, K2O, Na2O) with the majority of the trace elements indicate that the abundance of carbonate and clay minerals significantly influenced the concentrations of these elements during the weathering and transport of BR sediments. The average values of the Chemical Index of Weathering (CIW = 57.77%) and Chemical Index of Alteration (CIA = 60.70%) reflect moderately intense weathering in the basin. The Upper Continental Crust and Post-Archean Australian Shale normalized ratios, as well as a comparison between the sediment chemistry and the composition of the source rocks, would suggest that these elements were lost from source rocks during weathering, with Na2O experiencing a significant degree of loss. Moreover, the Fe2O3, MgO, and CaO normalized ratios show that these elements were derived from the closest supplied outcrops of source rocks, which are represented by the Late Campanian carbonate and clastic rocks (Tanjero and Shiranish) formations and the Pliocene (Red Bed Series) in the catchment areas. Available Upper Continental Crust and Post-Archean Australian Shale normalized ratios for trace elements showed high enrichment values of most trace elements and slightly enriched values of Sr. This means that Sr is effectively more solubilized and more mobile than other metals. Thus, this demonstrates how distinct rock sources from different geological formations contributed to an enrichment in the concentration of certain elements in the river sediments.

The study involved the determination of fluoride and other elements like Mn, Na, Mg, Si, K, Ca, Fe, Al, Cl and some trace elements (Cr, Cd, Ni, Zn, Pb, Sr, As, Co, Cu, Mo and Se) in 220 teeth samples with age group ranging from 6–45 year. The average concentration of fluoride in samples were less than the global average, and the total contents of fluoride in the children deciduous teeth are relatively higher than that of permanent teeth. The infection rate of dental caries in children seen in age between 6–11 years and increasing after the age of 12 due to certain environmental factors, age, water and food quality, so there is a strong relationship between the rising amount of fluoride concentration in the area and reducing the rate of dental caries. The study also determines the different limits and importantly the optimum value of fluoride concentration in drinking water of Kirkuk City which is done by correlation with the mean value of the maximum daily temperature of the city over the last five years, and also taking in consideration that human gets the fluoride from a different source such as food, air and tooth paste, so we correlate our finding with the rate of fluoride taken from other sources which not greater than 6mg/day, according to World Health Organization (WHO), in order to avoid the hyper fluorosis (excess fluoride).