Determination of mercury, lead, arsenic, cadmium and chromium in salt and water of Maharloo Lake, Iran, in different seasons

Background and purpose: Today, environmental pollutions are of the most important issues and hazardous in food safety around the world. Given the importance of salt and water in dietary, and extracting them from Maharloo Lake, Iran, this study aimed to investigate the concentrations of heavy metals, as environmental pollutions, in salt and water of this lake at different seasons. Materials and methods: In order to monitor heavy metals, including chromium (Cr), mercury (Hg), arsenic (As), cadmium (Cd) and lead (Pb), water and salt samplings were done in each season from August 2009 to May 2010. Using atomic absorption, the concentration of the mentioned metals was determined after digesting the samples. Results: The order of concentration of detected metals in different seasons in salt was Cr > As > Cd > Pb > Hg, and in water was Cr > As > Hg > Cd > Pb. In salt, the highest concentrations of Cr, Cd, Pb, and As were detected in spring and of Hg was seen in summer. Also in water, the highest concentrations of As and Cd were detected in spring, of Cr and Hg in summer, and of Pb in autumn. Conclusion: In summary, it could be concluded that the changes in the concentration of metals during different seasons was caused by the changes in the inlet water and human activities, especially agricultures. In addition, compared to Iranian standard, determined concentrations of Pb and Hg in salt samples were lower

Source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments (Case study: Pars special economic energy zone)

Background and purpose: Polycyclic aromatic hydrocarbons (PAH) compounds are amongst the most hazardous environmental pollutants due to some features such as chemical stability, low degradation, bioaccumulation, and high toxicity for living organisms. Their resources are found in Persian Gulf beaches, so, this study aimed at investigating the concentration, source identification, and ecological risk of PAH compounds in coastal sediments in Pars Special Economic Energy Zone (PSEEZ), Iran. Materials and methods: In order to assess the concentration of PAHs, 16 stations along the coast were selected and in each station two samples were collected. After preparation and extraction of samples using Soxhlet, the concentrations of these compounds were determined by HPLC. The toxicity evaluation indicators and diagnostic ratios were used to assess the ecological risk and determining their origin. Results: Mean concentration of PAHs in sediment was 292.72±54.44 ng/g dry weight. The mean effects range-median quotient of the PAHs (M-ERM-Q, M-PEL-Q), toxic equivalence quotient (TEQ), and mutagenic equivalence quotient (MEQ) showed that current values were less than the permissible limit. Comparison of PAHs concentration with sediment quality standards (NOAA, SQGs, and EPA) showed that the values for all compounds were lower than the standard limits (PEC, TEC, PEL, TEL, ERM). However, among these compounds, the average concentration of Acl was higher than the ERL standard and the concentrations of Acl, Ace, and Phe were higher than the EPA toxicity threshold. Conclusion: In this study, moderate PHAs pollution was seen in the region. Both petrogenic and fuel sources were found to be involved in introduction of these compounds into coastal sediments depending on the location of the station and its sources of contamination. Also, in terms of ecological risk, these compounds have low risks for living organisms. © 2018, Mazandaran University of Medical Sciences. All rights reserved

Determination and Ecological Risk Assessment of Heavy Metals (Cd, Pb, Cu, Zn) in Surface Sediments of Coastal Regions of Bushehr Province

Background: Persian Gulf is one of the most important ecosystems in the world that in recent decades has been exposed to various environmental pollutants such as heavy metals from human and natural activities. Therefore, the aim of this study investigates the concentration of heavy metals (cadmium, lead, copper and zinc) and ecological risk assessment of them in coastal sediments in of Bushehr province in Persian Gulf. Methods: In order to assess the concentration of metals, 54 stations along the coastal zones were selected and in each station three samples of sediment and plant were taken. After preparation and digestion of the samples, the concentrations of these metals were determined by using polarography. Results: The average of total concentration of detected metals Zn, Cu, Pb and Cd in sediment 52.40 ± 2. 62, 34.99±2.76, 11.53 ±2.01 and 2.41± 0.89 μg/g, respectively. Also, the results of comparison of heavy metals concentration in coastal areas in Bushehr Province (Jam, Deir, Bushehr, Dashti, Genaveh and Deilam) with ANOVA test showed there was a significant difference between the concentrations of sediments in different coastal areas. The results showed that the Pollution Load Index (PLI) and ecological risk represents less to moderately pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cd>Cu> Pb> Zn). Conclusion: According to the results, the pollution and ecological risk of metals in the region for Zn, Cu and Pb is low but for Cd is moderateevaluated

Determination of Heavy Metals Pollution Load Index in Sediments and Aquatic Plant (Nasturtium microphyllum) in Bashar River, Yasuj

Background: Pollution of aquatic ecosystems to heavy metals is one of the most important threats of human health and its food chain. Thus, in this study the concentration of heavy metals (lead, chromium, copper, and zinc) in Surface sediments and Nasturtium microphyllum was investigated in order to assessment their effects and ecological risk. Methods: In order to assess the concentration of metals, 8 stations along the river were selected and in each station two samples of sediment and plant were taken. After preparinng and digesting the samples, the concentrations of these metals were determined using Atomic absorbtion. Results: The average of total concentration of detected metals Cr, Pb, Cu and Zn in sediment (10.33 ± 0. 02 > 13.35±1.10 > 33.07 ±6.13 > 44.02± 4.13) mg/kg respectively. In addition, evaluation indicators such as; Pollution Load Index (PLI) and ecological risk represents less pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cu> Pb> Zn> Cr). The results of concentration of metals in different organs of root, stem and leaf of Nasturtium microphyllum showed that the highest average accumulated concentration for each metal was obtained in stem, root and leaf, respectively. Conclusion: According to the results, the pollution and ecological risk of metals in the region is low evaluated. The results of this study confirm the use of Nasturtium microphyllum as a heavy metals accumulation species and a suitable indicator for their biomonitoring

Water Quality Evaluation of the Intertidal Zone of Pars Special Economic Energy Zone in Differ-ent Seasons by Measuring the Concentration of Heavy Metals and Using WQI and TRIX

Background: Pars Special Economic Energy Zone (PSEEZ) in Bushehr province, Iran is a coastal ecosystem that is severely influenced by industrial and municipal activities. The present study was therefore conducted to monitor the health status of the intertidal zone of this ecosystem in different seasons using the Water Quality Index (WQI), Trophic Index (TRIX) and the concentration of heavy metals, including lead, copper, zinc and iron. Materials and Methods: To assess the desired indicators, 16 stations were selected along the region’s coast, and three samples were taken from each station. The required parameters of each index were then measured using standard methods. Results: Investigating the variations in WQI in different seasons found WQI to be the lowest (WQI=27.89) in winter, suggesting a bad status, followed respectively by summer (WQI=30.63), autumn (WQI=31.42) and spring (WQI=31.77), suggesting a relatively bad situation. The values of TRIX showed that the overall water quality of the intertidal zone is classified as oligotrophic. Moreover, the highest TRIX was associated with winter (TRIX=3.53) and the lowest with autumn (TRIX=1.93). The sequence of the overall mean concentrations of heavy metals in the water samples was also measured as Zn> Fe> Cu> Pb. Conclusion: The obtained findings attribute the high concentration of heavy metals and the low water quality of the coasts in winter to leaching contaminants from industrial, municipal and agricultural activities and the transmission of pollutants by surface currents to the coast of the region

Heavy Metals in Salt and Water Samples from Maharloo Lake and their Comparison with Metal Concentrations in Samples from Sirjan, Lar, and Firoozabad Salt Mines

Maharloo Lake is one of the most important water ecosystems in Iran, which is nowadays exposed to multiple risks and threats due to poor water management, salt extraction, and heavy metal pollution. In this study, the concentrations of such heavy metals as chromium, copper, zinc, arsenic, cadmium, and lead in both water and salt samples collected from areas in the north and south of the lake were determined by atomic absorption (AA-670G) after the samples had been digested. Results showed that metal concentrations in the salt samples taken from both the northern and southern areas had identical mean values in the order of Cr> Cu> As> Cd> Pb. An almost similar pattern was detected in metal concentrations in water samples taken from the same areas but with a slight difference in the way they were ordered (Cr> Cu> As> Pb> Cd). It was found that both water and salt samples collected from the northern areas had higher metal concentrations, except for that of Pb which was slightly lower. Comparison of the mean values of metal concentrations in the Salt Lake and those of Sirjan, Lar, and Firoozabad salt mines revealed that copper, cadmium, and lead had their highest concentrations in the Salt Lake while arsenic and chromium recorded their highest values in samples taken from Lar and Firoozabad salt mines, respectively. Based on these findings, it may be concluded that the increased metal concentrations observed in samples from both northern and southern areas of the lake are due to the sewage and effluents from urban, industrial, and hospital sources in Shiraz disposed into the lake as well as such other human activities as farming in the areas around the lake, especially in the northern stretches. These observations call for preventive measures to avoid further water quality degradation in the area

Measurement and Evaluation of Ecological Risk of Heavy Metals in Surface Sediments of Pars Special Economic Energy Zone

Background: Today, heavy metals pollution in aquatic ecosystems is one of the most important global environmental problems. Because this metals have characteristics such as chemical stability, low degradability and bioaccumulation ability at different levels of the food chain cause the abundant ecological risks for organisms. Therefore, this study investigates the concentration of heavy metals (mercury, cadmium, lead, chromium, copper, nickel, zinc and iron) and ecological risk assessment of them in coastal sediments in the Special Economic Energy Zone - South Pars. Materials and Methods: In order to assess the concentration of metals, 16 stations along the coast was selected and three samples were taken at each station. After preparation and digestion of the samples, the concentrations of these metals were determined by using Polarography. Results: The results showed that the average total concentration of metals in sediment were (Fe > Zn> Cu > Ni> Cr > Pb > Cd > Hg), to amount (56.065 ± 2.04 > 45.91±12.035 > 28.58±1.77 > 18.96 ± 0.84 > 8.59±0.47 > 0.447 ± 0.07 > 0.03 ± 0.016 mg/kg) respectively. In addition, evaluation indicators of the environment such as; Geo accumulation index (Igeo), Contamination factor (CF), Pollution Load Index (PLI) represents less pollution and partly average in the region. Also the investigation ecological risk and environmental risk of heavy metals showed the risk was alike with (Cd >Cu> Pb> Ni> Zn> Cr> Hg) respectively. Conclusion: According to the results, it can be concluded that pollution in the region for Hg, Zn, Cr, Pb and Ni were low and moderate for Cd and Cu. High concentrations of cadmium in comparison with the corresponding amount in the crust of the Earth, along with high levels of pollution factor, pollution modified for Cd, Cu implies the effects of human activities on pollution and accumulation of these heavy metals in sediments. Based on the calculation of the ecological risk index of metals we can expressed that among the measured elements, sediments in terms of Cadmium are in moderate ecological risk. &nbsp