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Showing 3 results for Ecological Risk Assessment
Ecological risk assessment of polycyclic aromatic hydrocarbons in the Persian Gulf surface sediments, Bushehr
F Bateni, A Mehdinia, M Seyed Hashtroudi ,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: This study conducted to assess ecological risk of an important group of pollutants called polycyclic aromatic hydrocarbons (PAHs) in offshore sediment of the Persian Gulf deposits in Bushehr province. The aim of this study was to model the toxicity of PAHs for aquatic organisms in the study area.
Materials and Methods: In the first step of the applied risk assessment model in this study, the unit of toxicity for each PAH and solubility were calculated by Quantitative Structure-Activity Relationships (QSAR) model. In the second step, the pore water concentration of all compounds in sediment was calculated as an available fraction. Finally, the proposed model was used to evaluate the offshore sediments of the Persian Gulf. Sediments in 19 stations and 7 transects were studied to assess the ecological risk of 21 PAHs. The extraction and clean up method was based on pressurized liquid extraction (PLE) with packed clean up cell. Compounds were analyzed by GC-MS.
Results: The toxicity and solubility of PAHs were modeled. The Pearson correlation for the predicted and measured data was more than 0.93. The amount of total toxicity was introduced as a risk index. The maximum and minimum total toxicity values for the sediments were found as 0.018 and 0.147, respectively. The results from this study indicated that although the concentration of PAHs in the sediments may not cause significant concern in the study area, they may affect benthic organism at the sub-lethal levels. According to the applied risk assessment model for 21 unsubstituted PAHs, the offshore sediments of Bushehr are in low-risk range.
Conclusion: The result of this study indicated a low risk of the sediments. The hazard index decreased as the distance from coastal and oil and gas industry increased, indicating the high impact of anthropogenic activities on the contamination of the study area.
 

Ecological quality assessment of Anzali wetland for heavy metals using heavy metals pollution index (HPI)
F Jaffari, N Hassanzadeh,
Volume 12, Issue 2 (9-2019)
Abstract 
Background and Objective: Research has shown that assessing the toxicity and ecological risk of various types of pollutants, including heavy metals, using specific indicators, is indispensable in the ecological risk assessment of the ecosystem. Accordingly, the aim of this study was the assessment of the ecological effect of heavy metals presence (Pb, Zn, Cu, Cd and, As) in Anzali wetland using Heavy Metals Pollution Index (HPI).
Materials and Methods: 43 water samples were collected from the eastern, western and central parts of Anzali wetland. The samples were transferred to the laboratory, and the preparation steps were carried out using the ASTM method. Concentration of the elements was determined by Inductively Coupled Plasma -Atomic Emission Spectroscopy (ICP-AES). According to the concentration of heavy metals in the water samples, the index (HPI) was calculated. The results of the HPI index were classified into three classes: low risk (<15), moderate (15-30), and high risk (> 30).
Results: The numerical value of the HPI index was 3.59-23.3 with an average of 27.97, indicating the average level of heavy metals pollution in Anzali wetland. Indicator (HPI) in the eastern part of Anzali wetland and ​​the Pirbazar area showed a severe contamination and ecological hazard of the heavy metals and in the Abkenar region showed an acceptable ecological status.
Conclusion: Although the average of HPI in the whole Anzali wetland was modest, but at some stations, especially in the east of the wetland, the HPI indicates the occurrence of ecological hazards in the wetland in the event of uncontrolled entry of pollutants in future. Therefore, monitoring the sources of these pollutants entering to the wetland and controlling the ecological risks is necessary.
 
Potential ecological risk assessment of arsenic, cadmium, nickel and vanadium in the surface sediments of southern of Caspian Sea (case study: Khazar Abad, Sari Township)
Arezoo Khalijian, Bahareh Lorestani, Soheil Sobhanardakani, Mehrdad Cheraghi, Lima Tayebi,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Soils and sediments contamination with trace and toxic elements lead to potential ecological risk and adverse effects on human health and so have been the cause of increasing concern worldwide. Therefore, this study was carried out to potential ecological risk assessment of As, Cd, Ni and V in surface sediments of Khazar Abad, southern parts of Caspian Sea in 2019.
Materials and Methods: In this descriptive cross-sectional study, a total of 36 surface sediment samples were collected from 12 sampling sites. After samples preparation, the elemental contents were determined using ICP-OES. Also, potential ecological risk factor (Eir) and cumulative potential ecological risk index (RI) were calculated. All statistical analyses were performed by SPSS software.
Results: Based on the results obtained, the mean contents of As, Cd, Ni and V in analyzed samples were found to be 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The computed values of Eir  showed that factor values were decreased in the order Cd > As > Ni > V. Additionally, the mean values of RI with 53.7 indicated that all the examined elements have the "low potential ecological risk".
Conclusion: Accordingly, although the examined elements have shown a low potential ecological risk, cadmium with 46.4% and arsenic with 45.4% mean values of RI can cause for concern. Therefore, source identification and management of organic and inorganic pollutants and also periodic monitoring of water and sediments as the sink of environmental pollution are recommended.

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