Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) in soils of different land uses in Erbil metropolis, Kurdistan Region, Iraq.

Urban soil contamination is a growing concern for the potential health impact on the increasing number of people living in these areas. In this study, the concentration, the distribution, the contamination levels, and the role of land use were investigated in Erbil metropolis, the capital of Iraqi Kurdistan. A total of 74 soil samples were collected, treated, and analyzed for their physicochemical properties, and for 7 heavy metals (As, Cd, Cr, Cu, Fe, Pb, and Zn) and 16 PAH contents. High concentrations, especially of Cd, Cu Pb, and Zn, were found. The Geoaccumulation index (Igeo), along with correlation coefficients and principal component analysis (PCA) showed that Cd, Cu, Pb, and Zn have similar behaviors and spatial distribution patterns. Heavy traffic density mainly contributed to the high concentrations of these metals. The total concentration of ∑PAHs ranged from 24.26 to 6129.14 ng/g with a mean of 2296.1 ng/g. The PAH pattern was dominated by 4- and 5-ring PAHs, while diagnostic ratios and PCA indicated that the main sources of PAHs were pyrogenic. The toxic equivalent (TEQ) values ranged from 3.26 to 362.84 ng/g, with higher values in central parts of the city. A statistically significant difference in As, Cd, Cu, Pb, Zn, and ∑PAH concentrations between different land uses was observed. The highest As concentrations were found in agricultural areas while roadside, commercial, and industrial areas had the highest Cd, Cu, Pb, Zn, and ∑PAH contents.

Polycyclic aromatic hydrocarbons (PAHs) in soils around oil refineries; Case study: Erbil and Kirkuk refineries, Iraq- A modelling approach.

Purpose: Political tensions in Iraq have made attention to environmental issues not a priority for the authorities. Therefore, the influence of Kirkuk and Erbil refineries on contamination of the surrounding soil by polycyclic aromatic hydrocarbons (PAHs), were studied. Methods: 25 soil samples were collected and analyzed using high-performance liquid chromatography (HPLC), and their fate and health risk were investigated using Exposure Model for Soil-Organic Fate and Transport (EMSOFT) and the Monte Carlo Simulation (MCS) model. Results: High ∑PAHs contamination (raged from 212.8 to 12,790.4 ppb), the dominance of pyrogenic sources, and high ecological risk were observed. The mean hazard index values for children (0.043) are higher than those for adults (0.02), while the incremental lifetime carcinogenic risk values for adults (8.50E-4) are greater than those for children (5.27E-4). Pyrene is the significant soil PAH from the depth of 3 cm downwards, while phenanthrene and fluorene are the major constituents of PAHs between the depth of 3 and 10 cm. Also, low molecular weight PAHs significantly decrease in soil layers over the time frame, and maximum PAHs concentrations belong to high molecular weight PAHs over 20 years. Conclusion: Using an appropriate monitoring system, as well as sound management decisions to reduce the emission of environmental pollution are needed. Also, it seems that the use of constant values for soil physicochemical parameters such as moisture and porosity, despite seasonal variations, may result in uncertainty for fate and transport modelling. Therefore, seasonal sampling and analysis of soil parameters, would be helpful. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-022-00809-y.

Heavy metal(loid) pollution of a hard-rock aquifer: evidence, distribution, and source.

Composition of groundwater in the mining areas can be affected by oxidation of sulfide minerals and related reactions. Given that in the Miduk copper mine area, groundwater is the only available water resource for drinking and agriculture purposes. In the study area, assessment and measurement of groundwater physicochemical properties such as pH, TDS, EC, major cations, and major anions were performed. Physicochemical studies showed that the calcium and sulfate are the main cations and anions (Ca-SO4 water type), respectively. Groundwater in the area is mainly fresh and with a source of meteoric water infiltration. Three pollution indices, HEI, HPI, and Cd, were selected to evaluate the concentration level of ten of heavy metal(loid)s (Al, As, Cd, Cu, Fe, Mn, Mo, Ni, Pb, and Zn). To investigate the source and relations between heavy metal(loid)s, multivariate statistical analysis was executed for eleven variables. The results of pollution indices showed that samples in group 1 (mine pit area) have the highest level of pollution and considering that the samples of this group are in the closest distance to the mine pit and group 3 (springs) around the study area had the least level of pollution. Multivariate statistical analysis showed a negative correlation between heavy metal(loid)s (with the exception of arsenic and molybdenum) with the distance from the mine pit. This suggested the origin of these elements can be considered as anthropogenic source due to mining activities. The geogenic source of arsenic, molybdenum, and lead can be cited based on Spearman's correlation coefficient supported by PCA analysis.

Bioavailability, distribution and health risk assessment of arsenic and heavy metals (HMs) in agricultural soils of Kermanshah Province, west of Iran.

Kermanshah Province as an agricultural hub exports food crops to neighboring countries. In this study, contamination status, bioavailability, spatial distribution, and ecological and human health risk of arsenic and heavy metals (HMs) in soil were investigate. For this purpose, 121 agricultural soil samples were collected and analyzed using ICP-MS. The data were studied by calculating some geochemical indices, and using geographical information system and statistical analysis. Results showed that Cd has the highest bioavailability, following by Cu and As. Also, Cu was severely associated with organic matter. Enrichment factor (EF) followed the order of As > Cu > Pb > Se > Cd > Zn > Ni > Cr, and the soil pollution index (SPI) ranged from 0.82 to 2.65. Low potential ecological risk was measured for most of the samples. However, Kermanshah County and Eastern parts of the Province showed the highest HMs enrichment and ecological risk. Moreover, high carcinogenic risk of Cr and Ni threatens the children. Cr showed also high non-carcinogenic hazard index (HI) for children. Principal component analysis (PCA) indicated the anthropogenic origins for As, Cd, Cu, Pb, Se and Zn, while Cr and Ni originated mainly from a geogenic source. Furthermore, Kruskal-Wallis H test revealed that As, Cd, Cr, Cu, Ni, Pb, Se and Zn concentrations were significantly different (p < 0.05) between 16 Counties of the Kermanshah Province. Overall, the management of urban and industrial contamination sources is required to minimize the concentration of bioavailable portion of HMs and preventing residents of the area from being exposed to contaminants.

High geogenic arsenic concentrations in travertines and their spring waters: Assessment of the leachability and estimation of ecological and health risks.

Travertines and their springs are rarely investigated as a source of toxicity. Remarkably high contents of As (up to 10 g/kg) have been found in travertine deposits and associated spring waters, nearby Ghorveh city (western Iran). Two types of travertines were distinguished: (i) Fissure ridge travertines, in areas with a carbonate-dominated basement, are characterized by a relatively low content and leaching of As. Their spring waters contain > 150 µg/L of As; (ii) Mound travertines, rich in non-carbonate impurities, occur in areas with volcanic substrates and contain high As concentrations (on average ~1,500 mg/kg) with high leachability. Their spring waters have lower As concentrations than equivalent fissure ridge waters. Principal Component Analyses of the elemental and mineralogical composition show the unstable association of As over a wide range of pH values to non-carbonate related elements, in particular iron, related to clay minerals. The high potential release of As may result in adverse ecotoxicological effects in surrounding agricultural soils and crops. An ecological risk assessment confirms the enrichment and very high potential ecological risk of As around mound carbonates. The human health risk assessment based on calculation via exposure factors suggests adverse non-carcinogenic and high carcinogenic risk with regard to As, both for adults and children.

Biosynthesis of reusable and recyclable CuO@Magnetite@Hen Bone NCs and its antioxidant and antibacterial activities: a highly stable magnetically nanocatalyst for excellent reduction of organic dyes and adsorption of polycyclic aromatic hydrocarbons.

For the first time, through a fast, eco-friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV-vis analytical techniques. Also, the radical scavenging activity using (2,2-diphenyl-1-picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV-vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.

Contamination, health risk, mineralogical and morphological status of street dusts- case study: Erbil metropolis, Kurdistan Region-Iraq.

Street dusts contamination by heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs), their mineralogical and morphological properties were investigated in Erbil metropolis. A total of 43 soil and street dust samples were collected and analyzed, and SPSS, ImageJ, X-powder and positive matrix factorization (PMF) software were used for data analyzing. Results showed the role of geology in mineralogical status of dusts. Based on ImageJ software processing, dust particles with diameters below 10 µm and low circularity and roundness were dominant. The enrichments for Hg, Cu, Pb and Zn contents were observed in compare with their calculated local geochemical baselines and geoaccumulation index, while, Ni, Co and Cr were categorized as particularly unpolluted. However, Hg, Cu and Pb showed the highest ecological risk (Eji) values among the studied elements, and 25.80%, 25.80% and 12.90% of the samples were classified as very high, moderate and considerable potential ecological risks, respectively. Hazard index (HI) followed the decreasing order of Pb > Cr > Cu > Ni > Hg > Zn > Co, and ingestion was the main exposure route particularly for children. The concentrations of individual PAHs ranged from 1.06 to 1000 ng/g, with the dominance of 3 and 4-ring compounds. Also, non-carcinogenic PAHs concentrations were higher than carcinogenic compounds and toxic equivalents (TEQs) ranged from 22.30 to 246.92 ng/g, with a max value in Northern industrial zone. Finally, source identification using multivariate statistics and PMF introduced three main PAHs and HMs sources in the study area including geogenic, traffic and industries, and incinerators (mainly for medical wastes).