رخساره عظیمی یانچشمه

In the last two decades, air pollution has become a serious problem, leading to a variety of harmful health effects. Street dust is a complex combination of pollutants from different sources, which can be a good indicator of air quality in the urban environment. So, this study was conducted to assess the health risk of toxic metals associated with street dust and identify their emission sources.

Dust samples were collected from three high-traffic districts in Karaj. After acid digestion, Cu, Zn, Cr, Mn, Ni, Ca, Ba, Sr, Li, Ti, Na, Mg, K, Fe, Al and V were measured using ICP-OES and Cd, Co, W and Pb were measured using ICP-MS.

The results of the measurement of elements in the street dust of Karaj indicated that compared to the amounts of elements in the earth's crust, the concentration (mg/kg) of Cd (X =0.9), Zn (X =479.15), Cu (X =159.37) and Pb (X =113.57) were at a very high level and the concentration (mg/kg) of Ni (X =69.36), Cr (X =93.96), Co (X =21.06), W (X =5.73) and Ca (X =75900) were at a relatively high level. In contrast, the concentrations of other elements (Ba, Mn, V, Sr, Ti, Li, Mg, Na, Ka, Fe, and Al) were in the range of values found in the earth's crust. Cluster analysis showed that Cd, Pb, Zn, Cu, Ni, Cr, Co, and Ca were mainly caused by anthropogenic activities, while other studied metals were associated with natural sources. Ingestion of dust particles was the main exposure pathway of toxic metals for both adults and children in Karaj. The Hazard Index (HI) in the children was higher than the adults, but it was lower than the safe level (HI≤1) in the both groups. Co, Cr and Cd had the highest carcinogenic risk among the studied metals.

The results of this study indicated that the street dust of Karaj is highly contaminated with toxic metals that long-term exposure with them can cause harmful effects, especially in children. Therefore, continuous monitoring of metal pollutants especially Co, Cr and Cd is recommended.

Atmospheric deposition has a significant influence on environmental pollution and human health because of its role on transport mechanisms. The aims of this study were the determination of Concentrations, Sources and Ecological Risks of trace elements in atmospheric deposition of Karaj City, Iran.

18 atmospheric deposition samples were collected from the flat roof of buildings in six districts and then, the concentration of elements including Cu, Zn, Cr, Ni, Li and other (Co and Pb) were analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS), respectively. Pearson Correlation, One-Way ANOVA and Factor Analyses were used to identify probable sources of the trace elements.

The mean concentrations of Pb, Zn, Cu, Cr, Ni, Co, and Li were 184.73, 931.75, 94.61, 98.79, 83.90, 21.05 and 24.71 μg/g, respectively. Also, the result showed the Enrichment Factors (EF) of Pb and Zn were high; Cr, Ni, and Cu were moderate while Co was unpolluted. Based on statistical analyses, trace elements could be originated from several anthropogenic (Vehicular Sources, Industrial Emissions and Fossil Fuel Combustion) and natural sources. Zn and Cu showed the highest concentrations at high-traffic stations, especially at Karkhene-Ghand located in city center. Maximum concentrations of Cr, Ni, and Co were observed at Fardis Station closed to Karaj Power Plant. Industrial Stations including Kamalshahr, Mohammadshahr, and Mahdasht had the most amount of Pb. Finally, Risk index (RI) showed all studied stations had low potential risk except of Kamalshar with a considerable risk.

Karaj has influenced by several anthropogenic sources of environmental pollution that are created many human health problems and the pollutants have increased with the population density. Therefore, we would have suggested the continuous monitoring of trace elements, especially Pb and Zn to control of the emission sources.

Air pollution is one of the most important problems in megacities. To provide comprehensive reduction plan for air pollution and pollutants emission prevention, first it must be estimated the amount and importance of major pollutants emission from various sources. The aims of this study were estimation the air pollutants emission from mobile sources and spatial modelling for each pollutant in Karaj. International vehicle emission model (IVE) was used to obtain air pollutants emission factors based on vehicle type. Finally, the annual pollutants emissions of vehicle fleet were calculated and spatial distribution of pollutants emissions based on traffic data and road networks were mapped in GIS environment. The results showed that the maximum annual emission of air pollutants including carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), particulate matters (PM) and carbon dioxide (CO2) were estimated about 1688.84, 185.61, 6.26, 31.16, 120.54 and 33737.04 t y-1, respectively. The highways and the heavy vehicles were the major source for PM and NOx. In addition, the arterial roads and light vehicles were the main source for CO and VOCs. Despite the highest SOx emission factor was for heavy vehicles, the total SOx emission from light vehicles was higher than heavy vehicles because of their numbers. Also, the highest emissions amount of pollutants in municipal districts of Karaj were in 3, 4 and 6 and the lowest amount were in 1, 8 and 9.

Human activities cause to the accumulation of heavy metals in soil. Soil pollution will significantly reduce environmental quality and affect human health. This study aimed to determine the concentration of some heavy metals (Ni, Pb, Fe, Zn, Cr and Cd) and evaluate the effects of Kerman steel industry on concentration of soil heavy metals. A total of 60 samples from the surface soil and a depth of 0-15 cm were collected at different distances from Kerman steel complex and analyzed with Atomic Absorption Spectroscopy (AAS). Some indices of pollution including Contamination factor (Cf), Pollution index (PI), Pollution load index (PLI), Pollution Intensity index (Ipoll), Potential contamination index (Cp) were calculated to assess the levels of soil contamination. The Pearson correlation, principal component analysis (PCA), hierarchical clustering analysis (HCA) was used to determine the origin of pollutants. The results were showed the trend of heavy metal concentration in the study area as Fe>Zn>Pb>Ni>Cr>Cd respectively. The maximum of studied indices was related to Pb and then Zn. Pearson correlation was showed that Zn with Cd and Pb with Cr had significant positive correlation. A PCA results of Cf index was stay Zn and Pb in the first cluster. In the other words, these two elements are more human origin. This study showed that the study area does not need to severe remedial action; however, continuous monitoring of environment is essential.

Urban and industrial development has increased concentration of heavy metals in the environment. The goal of this study was to assess the impact of Kerman steel complex on their surrounding soil by heavy metals.
This study was a snapshot and its type was descriptive-analytical research. Heavy metals contents from 60 soil samples (top soil, 0-15 cm) near two Steel Complexes were analyzed using flame atomic absorption spectroscopy (AAS). Source identification and pollution degree indices including enrichment factor (EF) and its percentage (EF%), geo-accumulation index (Igeo), contamination factor (Cf), degree of contamination (Cd) and modified degree of contamination (mCd) were calculated to assess the soil pollution level.
The average concentration of Ni, Zn, Fe, Pb, Cr and Cd were 9.98, 54.38, 15063.33, 20.86, 3.54 and 0.038 mg/kg, respectively. The order of average EF for heavy metals was Pb > Zn> Cd> Fe> Ni> Cr. Cf index also showed that 90% of the samples were moderately to significantly polluted with lead element. The results of EF% indicated that Fe (68.18%) had higher enrichment than others. The average values of Cd and mCd indices were 2.90 and 0.48, respectively, that showed low degree of pollution.
In this study, Pb and Cd concentration were related with activities of the steel complexes and other metals had a combination of natural and anthropogenic emission sources. The steel complexes should plan to reduce pollutants emission to their environment.

In recent years, enterance of oil contaminants especially polycyclic aromatic hydrocarbons (PAHs) to Anzali Wetland, has seriously threatened organisms life. Therefore, the current study was conducted to determine and compare concentration of PAH compounds with multiple sediment quality assessment indice to evaluate the ecological toxicity of surface sediments of Anzali Wetland and present appropriate management strategy. We randomly collected 22 surface sediment samples; each sample was dried and extracted based on the soxhlet method. Then during two-step of column chromatography the PAH compounds were separated and analyzed by gas chromatography equipped with a mass spectrometry detector (GC-MS). Total concentrations of these compounds ranged from 212 to 2674 ng g-1 d.w. with the mean of 907 ng g-1 d.w. The highest concentrations of PAHs was reported from stations (3-1 and 4-1) located in the vicinity of urban areas with shipping activities. In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in the majority of stations situated in low range values of adverse biological effects. Only in a few stations (3-1, 3-2 and 5-3), the concentrations of some of PAH compounds exceeded the low range of adverse biological effects. In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in Anzali Wetland rarely lead to adverse biological effects. However, concentrations of some of these compounds can cause acute toxic effects. Therefore, further studies including toxicity and bioaccumulation tests and survey of benthic community composition, especially in areas exceeded SQGs are essential for proper management.

Surficial sediments from the South-Western coast of the Caspian Sea (Anzali Port) were studied to determine the concentration and probable source of normal alkanes. In this regard, nine surface samples were collected and analyzed by gas chromatography–mass spectrometry (GC–MS). Concentrations of these compounds ranged from 743 to 6146 μg g-1 dw (average 2700 ± 1612 μg g-1 dw). Normal alkenes with long chain length were dominant in all studied stations. Based on used indices in this study, it was concluded that n-alkanes in sediments mainly come from petrogenic source, that was included the old oil spills (significant amount of UCM in all chromatograms) and recent inputs (high values for the ratios of n- C17/Pr and n-C18/Phy at some sampling sites). However, a contribution of hydrocarbons from higher and aquatic plants in the study area was observed.