Assessment of potentially toxic elements (PTEs) in atmospheric dry deposition of Hamedan Metropolis, west of Iran: pollution status, spatiotemporal variation, health risk implications, and source identification.

The present study was designed to assess concentrations, contamination levels, spatiotemporal variations, health hazards and source apportionment of potentially toxic elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and V) of atmospheric dry deposition (ADD) in Hamedan Metropolis. In so doing, a total of 144 atmospheric dry deposition samples were collected from 12 sites during four seasons in 2023. The concentrations of the analyzed PTEs in dry deposition samples were determined using ICP-OES after samples were digested with acid. The results illustrated that the average contents of As, Cd, Cr, Cu, Ni, Pb, and Zn with 4.52, 0.591, 4.01, 36.5, 42.5, 10.9, 84.6, 69.6, 178, and 3.91 mg/kg, respectively, were higher than those in the background samples reported for Iran, which could indicate the anthropogenic origin of these PTEs. The highest quantities of the tested PTEs in various seasons were observed in summer and/or fall samples and their highest amount in various functional regions pertained to the samples collected from the commercial or industrial regions, showing the effect of seasonal changes on emission sources and human inputs. Values of average contamination factor (CF), geo-accumulation index (I-geo), and enrichment factor (EF) ranged from 0.013 to 4.45, - 7.07 to 1.56, and 0.120 to 41.3, respectively, showing 'slight to high' pollution, 'unpolluted to moderately polluted', and 'no enrichment to very severe enrichment' levels, respectively. The pollution load index (PLI) with an average value of 0.680 reflected slight pollution levels in the entire study area. The average hazard index (HI) values of the tested PTEs for the residents were all within the safe limit (< 1). Additionally, the total carcinogenic risk (TCR) values showed that the carcinogenic risk of As, Cr and Ni for both target groups were at an acceptable level. Based on the positive matrix factorization (PMF) model, non-exhaust emissions and natural sources, fossil fuel combustion and industrial emissions, and traffic sources were identified as the primary contributors to ADD pollution, accounting for 26%, 38%, and 36%, of the total pollution respectively. In conclusion, further research is recommended to investigate the source-oriented ecological and health risks associated with atmospheric dry deposition pollution.

Pinus eldarica (L.) bark as urban atmospheric trace element pollution bioindicator: pollution status, spatial variations, and quantitative source apportionment based on positive matrix factorization receptor model.

In this study, a total of 180 Pinus eldarica bark samples were collected from different regions of Hamedan megacity, Iran, in 2023, and contents of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the samples were determined using ICP-OES. The results illustrated that the average contents of all the analyzed elements were greater than those in the background contents, which presumably demonstrated anthropogenic sources of these potentially toxic elements (PTEs). The greatest concentrations of the analyzed PTEs for different functional areas were observed in specimens collected from commercial or industrial areas, indicating the impact of human entries. The I-geo values were in the range of "unpolluted to moderately polluted" to "moderately to heavily polluted", PI showed "moderate to very high pollution", and PLI reflected high to very high pollution levels for the whole study area. Additionally, the cumulative mean value of ecological risk (RI) was found to be 152, demonstrating moderate ecological risk across the study area. The results of positive matrix factorization (PMF) showed that the PTE contamination in the air of Hamedan could mainly have an anthropogenic origin (82.7%) and that the traffic emissions as the primary pollution source (33.6%) make the highest contribution to the PTE pollution and ecological risks in the study area. In residential areas, demolition and construction activities could be considered the main sources of PTEs, while in commercial and industrial areas traffic emissions and industrial emissions, could be regarded as the main sources of such pollution, respectively. In conclusion, this study provides a useful approach to identifying the sources and contributions of the toxic elements in different functional areas and can inform future endeavors that aim at managing and controlling metal element pollution.

Removal of fluorouracil from aqueous environment using magnetite graphene oxide modified with γ-cyclodextrin.

Fluorouracil (FU) is a widely utilized antineoplastic medication in the pharmaceutical industry for combating gastrointestinal cancers. However, its presence in wastewater originating from pharmaceutical facilities and hospital effluents has a potential effect on DNA, and cannot be efficiently eliminated through conventional treatment methods. Consequently, the adoption of advanced technologies becomes crucial for effectively treating such wastewater. Accordingly, this study investigated the efficiency of magnetite graphene oxide nanocomposite functionalized with γ-cyclodextrin for removing fluorouracil from aqueous solutions. The magnetite graphene oxide nanocomposite functionalized with γ-cyclodextrin was synthesized via the hydrothermal method. Next, the effect of pH, temperature, adsorbent content, and contact time on the fluorouracil removal efficiency was explored. Ultimately, the experimental data were matched against Langmuir, Freundlich, and Temkin isotherms and Kinetic models. Accordingly, the efficiency of the absorbent used was dependent on the pH, contact time, temperature, and initial concentration of the adsorbent. The results indicated that the maximum removal efficiency for fluorouracil was achieved within the contact time of 45 min and adsorbent content of 0.020 g. In addition, the optimal pH for removing the medicine was 7. The conditions of the adsorption process followed Langmuir isotherm with correlation coefficients of 0.992 and a quasi-second kinetic model with a correlation coefficient of 0.999, with the maximum adsorption capacity of the adsorbent synthesized for the evaluated medicine estimated as 190.9 mg/g. The results showed that the magnetite graphene oxide nanocomposite functionalized with γ-cyclodextrin could be used as an effective and available adsorbent for removing fluorouracil from pharmaceutical wastewater.

Feasibility Study on Phytoremediation of Potentially Toxic Elements (Cd, Ni and Pb) in Aquatic Environments Using Suaeda maritima Plant Species, a Case Study: Khorkhoran International Wetland, Persian Gulf.

The current study was designed to assess the phytoremediation potential of Suaeda maritima has been assessed for cleanup of contaminated sediments with Cd, Ni and Pb. In so doing, totally, 20 sampling sites were selected in the Khorkhoran International Wetland. The contents of elements in sediments, plant organs and water samples were determined using ICP-OES. The mean contents of Cd, Ni and Pb (mg/kg) in the sediment samples were found to be 0.096, 38.1 and 1.78, respectively. Moreover, the mean levels of Cd, Ni and Pb (mg/kg) in root samples of S. maritime were 0.160, 2.72 and 1.22 respectively; whereas, in leaf samples they were found to be 0.157, 3.34 and 2.23 mg/kg, respectively. Furthermore, the mean contents of Cd, Ni and Pb (µg/L) in water samples were 243, 1440 and 3010, respectively. The values of BCF for Cd, BAF for Cd and Pb, and TF for Ni and Pb were higher than 1, which would indicate that S. maritima could possibly be a suitable candidate for the phytostabilization of Cd and the phytoextraction of Ni and Pb.

Sediment-connected Potentially Toxic Element Contamination and Phytoremediation Potential of Native Aquatic Macrophytes along the Jajrood River, Tehran Province, Iran.

This study was conducted to analyze Cu, Fe, and Pb contamination in sediments and also phytoremediation ability of bulrush (Typha Latifolia) and one-rowed water-cress (Nasturtium microphyllum) along the Jajrood River, Iran in 2022. In so doing, a total of 60 sediment and macrophyte samples were collected from four sites. The contents of the analyzed elements were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Also, the values of pollution index (PI), pollution load index (PLI), bioconcentration factor (BCF), bioaccumulation factor (BAF), transfer factor (TF) and metal accumulation index (MAI) were calculated. The results demonstrated that the average contents of Cu, Fe, and Pb were lower than those in the background, which presumably demonstrated natural sources of these metals. The greatest concentrations of analyzed elements for all the sediment and macrophyte samples were observed in specimens collected from S4 located at the end of the river, indicating the impact of anthropogenic entries from upstream areas on elemental accumulation in downstream section of the river. The values of PI reflected slight contamination. The higher BCF and lower translocation TF values of Fe and Pb in T. Latifolia and also Cu in N. microphyllum imply that these species could be suitable for their phytostabilization of above-mentioned elements from the sediment. This study provides evidenceas to the efficiency of T. Latifolia and N. microphyllum in bioremediation of Cu, Fe, and Pb in contaminated aquatic environments.

Honeybees (Apis mellifera L.) as a Potential Bioindicator for Detection of Toxic and Essential Elements in the Environment (Case Study: Markazi Province, Iran).

Honeybees, due to their wide-ranging foraging behaviour, have great potentials for monitoring environmental quality. Therefore, the purpose of this study was to use honeybees as bioindicators for the detection of toxic and essential metals (Cd, Cr, Cu, and Fe) in the environment. Totally, 180 soil, plant (including root and aerial part), honeybees, and honey samples were collected from 12 sites within the main beekeeping and honey production regions in Markazi Province, Iran in 2016. After acid digestion of samples, the metal concentrations were measured by inductively coupled plasma-optical emission spectrometers. The translocation factor (TF), and bioconcentration factor (BCF) of metals were computed. The results showed that among the analyzed bee samples, Cd (mg kg-1) was detected in amounts ranging from 0.01 to 2.35, Cr (mg kg-1) ranged from 0.02 to 18.10, Cu (mg kg-1) ranged from 2.00 to 39.11, and Fe (mg kg-1) ranged from 163 to 1695. BCF and TF values obtained showed that the Astragalus gossypinus would have a great accumulation ability for Cd and Cr. The results indicated that honeybees could be used to detect the spatial patterns of metal contaminations in the environment they dwell in.

Surveying the efficiency of Platanus orientalis bark as biosorbent for Ni and Cr(VI) removal from plating wastewater as a real sample.

Heavy metals make up one of the most important pollutants in industrial wastewater. For wastewater, adsorbent materials developed from suitable biomass can be effective in removing the heavy metal ions. In this study, the powder of the bark of Platanus orientalis was used as a biosorbent to remove Cr(VI) and Ni from a nickel-chromium plating wastewater as a real sample for the first time. Two different adsorbents were used in analyzing the data: modified and non-modified bark. The extent of adsorption was dependent on the pH (in the range of 1.5, 3, 5, 7, and 9), the time of contact (in the range of 30, 60, 90, 120 min), and the adsorbent dosage (different doses of 0.5, 1, 1.5, 2 g L-1). The concentration of unabsorbed metals was measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES, Model Thermo iCAP 6000). The maximum removal of Cr(VI) was obtained 89.6% for non-modified bark and 90.7% for modified bark both at pH of 5 in 2 g L-1 of adsorbent dosage in 300 min. While, the maximum Ni removal was obtained 74.5 and 56.5% for non-modified and modified bark, respectively, at pH 3 in 2 g L-1 adsorbent dosage in 90 min. Based on the results, Freundlich isotherm appears better fitted in adsorption with a better correlation coefficient (R2 = 0.998) than that of Langmuir model with a correlation coefficient of R2 = 0.996. The qmax for Ni1 and Ni2 were 126.58 and 285.714 mg g-1 and the qmax for Cr1 and Cr2 were 13.423 and 19.920 mg g-1, respectively. The FTIR studies indicated that S-O stretching group from sulfonate, surface O=H stretching, and also aliphatic C-H stretching are responsible for the adsorption. The SEM results obviously show the difference between the biomass surface before and after loading of ions. Ultimately, the present study concluded that P. orientalis could be a cheap and efficient biosorbent to adsorb and remove Cr(VI) and Ni from the plating wastewater; however, it seems more efficient for Cr(VI) with an average removal power of 90.15% than Ni with an average removal power of 65.75%.

Developing a bioindicator in the northwestern Persian Gulf, Iran: trace elements in bird eggs and in coastal sediments.

Levels of arsenic (As), cadmium (Cd), cobalt (Co), lead (Pb), nickel (Ni), selenium (Se), and vanadium (V) were evaluated in coastal sediments, egg contents, and eggshells of crab plover (Dromas ardeola), bridled tern (Sterna anaethetus), lesser crested tern (S. bengalensis), and western reef heron (Egretta gularis) breeding in the northwestern Persian Gulf. Levels of Cd, Pb, Ni, V, and Se were greater in eggs of terns than in eggs of crab plover, perhaps due to the higher trophic level of terns. Levels of all elements were lower than known effects levels for birds. However, levels of Se in eggs were greater than those known to cause toxic effects in birds. Eggs of terns are ideal for monitoring metal contaminants on the breeding grounds because the bioaccumulation ratios (egg/sediment) of some metals (As, Co, Se) in the eggs of terns are significantly greater compared with those of crab plovers.

2,4-Dinitrophenylhydrazine functionalized sodium dodecyl sulfate-coated magnetite nanoparticles for effective removal of Cd(II) and Ni(II) ions from water samples.

2,4-Dinitrophenylhydrazine immobilized on sodium dodecyl sulfate (SDS)-coated magnetite and was used for removal of Cd(II) and Ni(II) ions from aqueous solution. The prepared product was characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The size of the nanoparticles according to SEM was obtained around 20-35 nm. In batch tests, the effects of pH, contact time, initial metal concentration, and temperature were studied. The kinetic and equilibrium data were modeled with recently developed models. The adsorption kinetics and isotherms were well fitted by the fractal-like pseudo-second-order model and Langmuir-Freundlich model, respectively. Maximum adsorption capacity by this adsorbent is 255.1 mg g(-1) for Cd(II) ion and 319.6 mg g(-1) for Ni(II) ion at pH 7.0 and 25 °C. The method was successfully applied to the removal of metal cations in real samples (tap water, river water, and petrochemical wastewater).

UiO-66-NH2/guanidine-functionalized chitosan: A new bio-based reusable bifunctional adsorbent for removal of methylene blue from aqueous media.

Methylene Blue (MB) is a common pollutant found in industrial wastewater, and its removal is crucial to ensure environmental sustainability. Due to MOFs have high surface area, tunable pore size distribution, and excellent adsorption capacity, in the current study, Uio-66-NH2@Cs-ISo-Gu nanohybrid was prepared through soluthermal method and then was used to remove MB dye. The results displayed that dye optimal adsorption by Uio-66-NH2@Cs-ISo-Gu nanohybrid occurred in the first 40 min, pH = 8, and low dye concentrations. Also, with increasing temperature, the amount of adsorption has decreased, which indicated the adsorption process would be exothermic. Based on the results, the Uio-66-NH2@Cs-ISo-Gu nanohybrid has a surface area of 120.9 m2.g-1 and a type IV isotherm. Also, the Freundlich isotherm and pseudo-second order models had the best agreement with the experimental data. The maximum adsorption capacity for this nanohybrid was 178.571, 153.846, and 135.135 mg.g-1 at 25 °C, 45 °C, and 65 °C temperatures, respectively, which could be successfully used as an excellent adsorbent in treatment of wastewater. However, further research is needed to understand the underlying adsorption mechanism and optimize the process for efficient removal of MB from contaminated water sources.

A fuzzy interval dynamic optimization model for surface and groundwater resources allocation under water shortage conditions, the case of West Azerbaijan Province, Iran.

The allocation of water in areas which face shortage of water especially during hot dry seasons is of utmost importance. This is normally affected by various factors, the management of which takes a lot of time and energy with efforts falling infertile in many cases. In recent years, scholars have been trying to investigate the applicability of fuzzy interval optimization models in attempts to address the problem. However, a review of literature indicates that in applicating such models, the dynamic nature of the problem has mostly been overlooked. Therefore, the aim of the present study is to provide a fuzzy interval dynamic optimization model for the allocation of surface and groundwater resources under water shortage conditions in West Azerbaijan Province, Iran. In so doing, an optimization model for the allocation of water resources was designed and then was validated by removing surface and groundwater resources and analyzing its performance once these resources were removed. The model was then applied in the case study of ten regions in West Azerbaijan Province and the optimal allocation values and water supply percentages were determined for each region over 12 periods. The results showed that the increase in total demand has the greatest effect while the increase in groundwater industrial demand has the least effect on the supply reduction rate. The increase of uncertainty up to 50% in the fuzzy interval programming would lead to subsequent increases in groundwater extraction by up to 19% and decreases in water supply by up to 10%. The increase of uncertainty in the fuzzy interval dynamic model would cause an increase in groundwater extraction to slightly more than 10% and a decrease in water supply to 0.05%. Therefore, implementing the fuzzy interval dynamic programming model would result in better gains and would reduce uncertainty effects. This would imply that using a mathematical model can result in better gains and can provide better footings for more informed decisions by authorities for managing water resources.

Fabricating modified carbon sesame straw for adsorption of acetaminophen and ibuprofen from aqueous media: isotherm and kinetic models.

As acetaminophen (ACT) and ibuprofen (IBP) have serious environmental impacts, despite their widespread use in many countries, the present research examined the effectiveness of activated carbon made from straw and sesame stubble in removing ACT and IBP from water. To that end, the as-synthesized adsorbent was functionalized using zinc chloride. The maximum adsorption capacities were found to be 51.7 mg g-1 for ACT and 63.7 mg g-1 for IBP. The adsorption kinetics and isotherm results showed that the pseudo-second-order (PSO) kinetics and Langmuir isotherm fit the data obtained from this study better than the other experimental models do. Also, the adsorption reached equilibrium within 120 min, and the optimal adsorbent dose and temperature were obtained as 1.0 mg and 25 °C, respectively. The mechanisms involved in the adsorption process would include acid-base, hydrogen bonding, electrostatic forces, and π-π interaction. Reusability studies revealed that the adsorbent still preserved about 89% and 82% of the adsorption performance for ACT and IBP, respectively, after seven repeated adsorption cycles. As the findings indicated, CSS/Zn could be accepted as a hopeful adsorbent to be used in pharmaceutical treatment.

Groundwater quality modeling using a novel hybrid data-intelligence model based on gray wolf optimization algorithm and multi-layer perceptron artificial neural network: a case study in Asadabad Plain, Hamedan, Iran.

Monitoring and assessment of groundwater quality (GWQ) as an important freshwater source for drinking purposes in urban and rural regions of developing countries due to rapidly increasing contamination is one of the concerns of water managers. Therefore, developing an efficient intelligent model for analyzing GWQ could help hydro-environmental engineers for sustainable water supply. The current research investigated the applicability of a novel nature-inspired optimization algorithm hybridized with multi-layer perceptron artificial neural network based on gray wolf optimization (GWO) for estimating dissolved oxygen (DO) total dissolved solid (TDS) and turbidity parameters at Asadabad Plain, Iran, and results are compared with the stand-alone multi-layer perceptron artificial neural network (MLPANN), generalized regression neural network (GRNN), and multiple linear regression (MLR) approaches. Evaluation of performance of models is carried out using various statistical indices like relative root mean square error, Nash-Sutcliffe efficiency, and correlation coefficient. Based on the results obtained, it is found that the hybrid GWO-MLPANN is a beneficial GWQ forecasting tool in accordance to high performance accuracy. Also, the study found that the superiority of the applied meta-heuristic algorithm (GWO) in improving the performance accuracy of the stand-alone artificial intelligence techniques in modeling the GWQ parameters.

Magnetite graphene oxide modified with ß-cyclodextrin as an effective adsorbent for the removal of methotrexate and doxorubicin hydrochloride from water.

The purpose of this investigation was to analyze the performance of magnetite graphene oxide modified with ß-cyclodextrin (GO@Fe3O4@ß-CD) for adsorption of methotrexate (MTX) and doxorubicin (DOX) from aqueous solutions. Characterization of GO@Fe3O4@ß-CD was carried out using some methods. The perfect conditions for the adsorption of MTX and DOX were 7.0, 45 min, 20 mg, and 25 °C for solution pH, contact time, adsorbent dose, and temperature, respectively, with removal efficiency values of 97.8% and 98.5% for MTX and DOX, respectively. The adsorption kinetic of MTX and DOX via GO@Fe3O4@ß-CD followed pseudo second-order (PSO) model, while the adsorption isotherm obeyed Langmuir model by monolayer adsorption with maximum adsorption capacities of 198.5 and 204.5 mg g-1 for MTX and DOX, respectively. Therefore, it could be argued that HCl and 0.1 mol L-1 NaOH would reflect adequate elution properties for GO@Fe3O4@ß-CD recovery.

Ecological and human health risks assessment of some polychlorinated biphenyls (PCBs) in surface soils of central and southern parts of city of Tehran, Iran.

PURPOSE: The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazards of polychlorinated biphenyls (PCBs) in topsoil across business districts, public green space, cultural and educational areas, and roadside and residential areas in city of Tehran, in 2019. METHOD: A total of 30 surface urban soil specimens were collected and after preparing them in the laboratory, PCBs contents were determined using gas chromatography-mass spectrometry. RESULTS: Based on the results of data analyses, the median concentrations of PCB18, PCB28, PCB 29, PCB 31, PCB 44, PCB 52, PCB 101, PCB 138, PCB 141, PCB 149, PCB 153, PCB 189 and PCB 194, were found to be 6.81, 0.759, 0.005, 1.75, 2.51, 0.059, 2.31, 3.76, 5.82, 0.599, 0.408, 0.008 and 0.008 µg/kg, respectively. Also, the overall daily PCBs intakes via soil ingestion, inhalation and skin contact were 5.48E-04, 1.19E + 00 and 1.62E-04 µg/kg, respectively. Thus it was decided that the inhalation of soil could be the main pathway of exposure to PCBs, and that, based on the carcinogenic risk outcomes, children would be more at risk of cancer than adults would. CONCLUSIONS: In general, considering that among the studied urban spaces, the contents of PCBs in public green spaces were more than their rates in other areas, and considering that children normally play in the green areas are, it is recommended that special attention be paid to these areas in controlling and removing pollution caused by PCBs in urban areas.

Evaluation of some chelating agents on phytoremediation efficiency of Amaranthus caudatus L. and Tagetes patula L. in soils contaminated with lead.

PURPOSE: This study was designed to evaluate the possible effects of some chelating agents on phytoremediation efficiency and plant growth parameters of Amaranthus caudatus L. and Tagetes patula L. in soils contaminated with lead. METHOD: The plant species were grown in pots and treated with lead nitrate and in combination with 2.5, 2.0 and 2.5 mmol/kg of EDTA, SA and CA, respectively. RESULTS: The results showed that the highest accumulations of Pb (mg/kg) with 0.74 and 0.13 were found in the roots and stems of A. caudatus exposed to 400 mg/kg Pb containing EDTA and SA, respectively. Moreover, the highest accumulation of Pb in the roots and stems of T. patula with 0.87 and 1.5 mg/kg were observed in 400 mg/kg Pb- contaminated soil containing SA. CONCLUSIONS: Although the results obtained showed that T. patula would have a better phytoextraction potential than A. caudatus, it should be noted that due to the Pb behavior in the soil and/or leaching of Pb from the soil columns during the irrigation period the low amounts of Pb absorption by the root and aerial parts of the plants compared to the added doses of Pb(NO3)2 solution to the soil samples, imply the studied plants haven't the adequate potential for phytoextraction of Pb from contaminated soils.

Analysis and health risk assessment of phthalate esters (PAEs) in indoor dust of preschool and elementary school centers in city of Tehran, Iran.

Individuals spend a lot of time indoors; thus they are generally exposed to phthalates used in consumer products. Therefore, those exposed to phthalates as indoor contaminants are at high risks. The present study was conducted to evaluate the carcinogenic and non-carcinogenic hazard of phthalate esters (PAEs), like dimethyl phthalate, diethyl phthalate, di(nbutyl) phthalate, butyl benzyl phthalate, dioctyl phthalate, and di(2-ethylhexyl) phthalate in the dust obtained from 21 schools in Tehran, in 2019. A total of 63 indoor dust specimens were obtained by a vacuum cleaner. After transferring dust samples to the laboratory, 100 mg of each sample was centrifuged and mixed with 20 ml acetone and kept through a night and ultrasonicated within 30 min. Eventually, PAEs' contents were measured via gas chromatography-mass spectrometry. Based on the findings, median concentrations of DMP, DEP, DnBP, BBP, DEHP, and DnOP were 0.90, 0.10, 6.0, 0.20, 118.30, and 4.10 mg kg-1 respectively. Moreover, the overall average daily exposure doses (ADD) of phthalate esters via dust ingestion, skin contact, and inhalation were 1.56E-03, 1.70E-06, and 1.56E-07 mg kg-1 day-1, respectively, and the lifetime average daily exposure doses (LADD) were 1.83E-04, 2.34E-08, and 2.46E-08 mg kg-1 day-1, respectively; thus ingestion of dust particles was found to be the main pathway of exposure to phthalate for non-carcinogenic and carcinogenic risks. Although based on the results, the studied samples were below the US Environmental Protection Agency threshold of 1.00E-06, due to the disadvantages of phthalates in human safety, these kinds of investigations are helpful in understanding the main ways of exposure to PAEs and providing a science-based framework for the future attempts for mitigating the PAEs indoor emissions.

Heavy metal concentrations in roadside plants (Achillea wilhelmsii and Cardaria draba) and soils along some highways in Hamedan, west of Iran.

The present study was conducted to analyze the effects of traffic volumes on Cd, Cu, Pb, Ni, and Zn contents in roadside soils and in two dominant herbaceous species (Achillea wilhelmsii and Cardaria draba) along highways and to evaluate the dynamic characteristics of these elements and their accumulation by the aerial parts and roots of these herbaceous species. The plant samples were collected along 700 m of a 9-km segment of each of the three major highways in Hamedan Province (West Iran) with different traffic volumes: Hamedan-Goltapeh (HG), Hamedan-Razan (HR), and Hamedan-Kermanshah (HK). The results indicated that the mean contents of Cd, Cu, Pb, Ni, and Zn in the soil samples were 0.26, 18.74, 14.98, 18.21, and 62.25 mg kg-1, respectively. Furthermore, the mean contents of elements (mg kg-1) in aerial parts of A. wilhelmsii were 0.16 for Cd, 4.52 for Cu, 1.91 for Pb, 1.70 for Ni, and 44.80 for Zn, while in the aerial part samples of C. draba, the concentrations (mg kg-1) and the mean contents were 0.16, 2.29, 2.58, 1.60, and 31.29, respectively. This meant that the traffic volume affected the contents of the metals in the soil and the herbaceous species. The metal content in herbaceous tissues varied significantly between plant species. A. wilhelmsii tended to accumulate the metals in the roots while C. draba retained them mostly in the aerial parts. The significant positive correlations of Cd, Cu, Ni, and Zn content in root and aerial parts of the herbaceous plant with those found in the soil samples showed the potential of the studied species for application in biomonitoring studies. Comprehensive analysis (effect of traffic volumes and relationships between the content of elements in plant tissues and soil samples) indicated that Cu in both herbaceous plants was mainly derived from soil, while A. wilhelmsii absorbed Cd and C. draba absorbed Zn mainly through the stomata from atmospheric depositions. Without considering atmospheric depositions due to intense traffic volumes, in A. wilhelmsii, the translocation factor (TF) values of Cu and Zn were 1.06 and 1.44, respectively and in C. draba, the TF values of Cd, Cu, and Pb were 1.06, 1.09, and 1.13, respectively, thus suggesting that both herbaceous species had high potentials for transferring metals from the roots to aerial parts.

Analysis, spatial distribution and ecological risk assessment of arsenic and some heavy metals of agricultural soils, case study: South of Iran.

PURPOSE: In this study, rates of arsenic, cadmium, chromium, copper, lead and zinc contents in agricultural soils from Eghlid County, south of Iran, were determined to assess the soil pollution and potential ecological risk index (PERI) and also spatial distribution of such elements. METHOD: A total of 100 topsoil specimens were collected from 100 sampling stations. In the laboratory, after acid digestion the element contents in soil samples were determined using ICP-OES. Then, the soil contamination and also ecological risk of the soil were assessed using various indices especially Igeo, PI, IPI, PLI and PERI. Also, the spatial distribution maps of the studied elements in soil specimens were made using the kriging interpolation technique by ArcGIS software (10.4). RESULTS: Based on the results, the mean contents (mg/kg) of the elements in specimens were 1.85, 2.80, 19.04, 19.35, 7.17 and 38.77 for As, Cd, Cr, Cu, Pb and Zn, respectively. Arsenic and Cu contents were comparable to background values, while Cd contents were higher than their corresponding background values. The results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that Cd had anthropogenic sources; while, other elements originated from natural sources. Pollution index (PI) values of As, Cd, Cr, Cu, Pb and Zn varied in the range of 0.45-1.49, 0.52-32.09, 0.096-0.33, 0.36-1.35, 0.18-0.32 and 0.23-1.59, with mean values of 0.92, 12.17, 0.21, 0.68, 0.21 and 0.96, respectively. The integrated pollution load index (PLI) values of the specimens with an average value of 0.84, indicated that 65% and 35% of soil samples were moderately and low contaminated, respectively. The mean value of PERI with 380.32 implied that the agricultural soils of the study area could be classified of high ecological risk. The spatial distribution of content of the elements showed that Cd had high spatial variability. CONCLUSIONS: Although in the short run, the contents of the elements found in the agricultural soil samples may not be alarming for agricultural production and consequently human health, signals it can be observed especially for Cd in the long term due to the impact of anthropogenic activities that lead to the discharge of this element to the environment and can result in its accumulation in agricultural soils. In conclusion, as it is expected that the metal inputs increase in the future, it is recommended that plant analyses be included in the future studies for determining the impact of the amount of bioavailable metals.