جستجوی مقالات مرتبط با کلیدواژه « فاکتور غنی شدگی » در نشریات گروه « پزشکی »

Heavy metal contamination of surface soils has become a serious concern. The aim of this study was to evaluate the potential risk of heavy metal (loid) pollution on human health in the surface soils of Arak industrial areas, the capital of Markazi province in western Iran.

235 surface soil samples were collected from a depth of 0-5 cm. Concentrations of lead, cadmium, nickel, zinc, copper and arsenic were determined by digestion with nitric acid (4 N). The level of soil pollution in the region was measured using geo- accumulation index (Igeo) and enrichment factor (EF). The model proposed by the U.S Environmental Protection Agency (USEPA) was used to assess the health risks of heavy metals.

The Mean concentrations of Pb, Cd, As, Cu, Ni, and Zn were 37.88, 1.17, 151.78, 13.48, 92.98 and 104.04 mg/kg, respectively. The calculated enrichment factor values ​​for soil samples varied from deficiency to significant enrichment. The mean geo-accumulation index (Igeo) for Pb, Cd, Cu, Ni, Zn and arsenic were 0.37, 1.59, -2.53, -0.48, -0.63 and 2.9, respectively. The results of the health risk assessment showed that hazard quotient (HQ) for children and adults through the ingestion route was higher than dermal contact and inhalation pathway. The Hazard index values for all studied metals were lower than the safe level of 1 except for As. Arsenic showed the highest risk of carcinogenicity (CR) for children (2.37 x 10-4) through ingestion.

The carcinogenic risk (CR) of As in children and adults is higher than the safe limit of 1 × 10-4, which indicates an unacceptable risk.

Atmospheric dust particles play a significant role in the transfer of chemical elements released from industrial and urban sources. So that the contaminants attached to these particles, can be transported over long distances and are as a function of meteorological conditions, the physical and chemical properties and nature of surface. The aim of this study was to evaluate the metal richness and degree of heavy metal contamination in atmospheric deposited dust in Tehran.

Atmospheric dust samples were collected from eight locations in Tehran in 2018. Heavy metals (Pb, Zn, Cu, Ni, Cr, Mn and Al) were analyzed in dust using ICP-MS. Metal richness and degree of contamination were determined using Enrichment Factor (EF), Geoaccumulation Index (Igeo), degree of Contamination (Cd) and modified degree of contamination (mCd). Paired t-test, Pearson correlation and Hierarchical cluster analysis (HCA) were also used for analysis.

The mean concentration trend of elements in the warm and cold seasons was similar as Al>Zn>Mn>Pb>Cu>Cr>Ni. Results of enrichment factor index in atmospheric deposited dust showed that Pb and Zn in warm season and Pb and Cu in cold season were highly enriched. Paired t-test results showed a significant difference between Cu and Cr between seasons. Cluster analysis also showed Al of natural origin and other elements of anthropogenic origin.

The results of this study showed that atmospheric deposited dust particles of Tehran have high levels of contamination especially in cold season. Therefore, it is necessary to formulate more effective and practical policies to improve Tehran’s air quality.

Heavy metals in urban parks are one of the most important indicators of urban pollution, as children playing in the park can readily be affected. This research was conducted to evaluate the environmental pollution of some heavy metals in Ahvaz parks. To this end, 26 sampling stations were selected from 20 parks in Ahvaz city and the soil samples were analyzed by inductively coupled spectroscopy (ICP-OES) method. The pollution levels of heavy metals were calculated based on enrichment factor, Index of Geo accumulation, pollution index and Nemerow integrated pollution index. The average concentrations of heavy metals of Cr, Zn, Ni, Pb, Cu and V were 167.26, 131.92, 78.75, 51.83, 28.71 and 12.49 mg/kg, respectively. The average concentrations of all heavy metals except Cu and V were several times higher than the base content. Based on the average EF and PI in the study area, heavy metals of Ni, Zn and Pb had high contaminations. Moreover, the highest mean of Igeo was related to Ni, Zn and Pb. According to NIPI results, 100% of samples had high degree of contamination. The results showed that the contamination source of evaluated metals was anthropogenic activities, including vehicle traffic and burning fossil fuels. Parks in Ahvaz were polluted by heavy metals, so these results may be useful for planning, risk assessment and decision making by city administrators.

Background and The aim of the present study was to investigate the concentration, enrichment factor, Nemrow integrated pollution index, and potential ecological risk of heavy metals including (Pb, Ni, Cu, Zn, Cd, V and Cr) in surface soils of Ahvaz oil filed.
For this purpose, 49 soil samples with a systematic scheme from Ahvaz oil field were analyzed by atomic absorption method.
The mean concentration of heavy metals was as follow: Pb (251.20), Ni (94.6), Cu (75.80), Zn (132.84), Cd (0.69), V (4.97) and Cr (141.48) (mg/kg). The average value of enrichment factor in the soil samples decreased as Pb>Ni>Cu>Cr>Zn>Cd>V. Nemrow integrated pollution index (NIPI) indicated high level of pollution for the studied heavy metals except V. The Potential ecological risk of the studied heavy metals showed a low potential ecological risk for V, Cd, Zn and Cr; Cu showed a moderate risk and Ni and Pb indicated a considerable ecological risk. The mean value of the risk index indicated that 27 (55.10%) of the soil samples with a moderate risk, 21 (42.85%) with a considerable risk and one sample (2.05%) with a high ecological risk.
The obtained results from the enrichment factor, Potential ecological risk, and risk index indicated that the main source of heavy metals in the study area were anthropogenic sources such as oil drilling activities.

Street dust is considered as one of the important sources of particulate matters and heavy metals in the atmosphere. The goal of this study was to assess the heavy metals pollution in street dust of Tehran and evaluate their ecological risk.
The sampling of street dust was carried out in two areas at the east and west of Tehran. After preparation of samples, the concentration of heavy metals was measured by ICP-MS. The pollution level of heavy metals in the street dust was assessed using geo-accumulation index (Igeo), pollution index (PI), integrated pollution index (IPI), enrichment factor (EF) and ecological risk index (RI).
The results of the calculations of the indices showed that the street dust in both studied areas was non-polluted with Li, Al, Ti, V, Cr, Mn, Fe, Ni, Sr and Ba. The origin of these elements was mainly natural sources. However, Cd, Cu, As, Zn, Sn and Pb had medium to high level of contamination. These elements had a very high to extremely high enrichment in both areas. Their origin was mainly anthropogenic sources. The ecological risk index indicated a moderate ecological risk for the east and a low ecological risk for the west area.
The higher level of lead in the East is the main reason of higher ecological risk of this area. Therefore, the heavy metals pollution of the street dust, especially lead and its enterance into the environment, should be considered in this area.

The aim of this study was to investigate the physico-chemical properties, size distribution and shape of the falling mineral dusts over Masjed Soleyman and to identify their origins. Also, seasonal and annual variations of climatic parameters and their relation with dust storm occurrence were investigated.
The collected samples were as result of dry deposition process during warm season in 2013. Particle size distribution was determined by laser size diffraction. Chemical and mineralogical compositions were measured with atomic absorption spectrophotometer (AAS) and X-ray diffraction (XRD). Crustal and non-crustal origins for elements in the dust samples were determined using enrichment factor (EF). In addition, dust storm sources were identified using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT.4).
The study of the annual and seasonal changes in meteorological parameters associated with the occurrence of dust storms indicated an agreement between the occurrence of dusty days, temperature and rainfall in summer. The chemical and mineralogical analysis of dust particles demonstrated that the likely origin of these particles is of neighboring countries in the South West of Iran. Also, some of the detected trace elements had non-crustal sources.
Using HYSPLIT.4 results, it was concluded that the main origin of dust storms are North West of Iraq and East of Syria in Masjed Soleyman.

Street dust reflects one of the most important indicators of pollution in the urban environment. Most studies carried out in the world on heavy metal pollution are related to cities and metropolitans¡ while less attention has been paid to towns. Masjed-e- Soleiman¡ the most oil-rich town is located in the north eastern part of Khuzestan Province in Iran. This town contains geogenic pollutants such as gas and oil sources¡ oil and gas activities¡ oil and gas combustion¡ industries¡ and heavy traffic¡ which make it important from the viewpoint of environmental impact assessment.
For monitoring and management of pollution¡ 11 samples of street dust were collected and prepared from different stations within the town during the dry season (June 2013). Each sample was analyzed using ICP-OES instrument.
Possible sources of the heavy metals were identified by multivariate analyses such as Principal Component Analysis (PCA) and Cluster Analysis (CA). In addition¡ factors such as the Index of Geo-accumulation (Igeo)¡ Pollution Index (PI)¡ Integration Pollution Index (IPI)¡ and Enrichment Factor (EF) were assessed to determine the degree of heavy metals pollution in street dust of the Masjed-e- Soleiman Town. The results of PCA and CA indicated that the region is mostly affected by oil pollution (both natural and combustion of fossil fuels)¡ traffic¡ and industrial activities (PI revealed high levels of Pb¡ Cd¡ Cu¡ and Zn pollution in samples and the average level of Ni¡ As¡ and V pollution in other samples). Igeo indicated the moderate to severe pollution of some samples to Pb¡ Cd¡ Cu¡ and Zn while no to moderate pollution against Ni¡ As¡ and V in other samples. EF for Pb¡ Cd¡ Cu¡ and Zn showed a significant pollution in some samples and other samples represented the least pollution against Ni¡ As¡ and V.
Results showed that the concentrations of heavy metals in dust samples were higher than control samples in Masjed-e- Soleiman. Thus¡ the classification of pollution in street dust in Masjed-e- Soleiman is as follows: IPI> EF> Igeo ≈ PI.