Iranian Journal of

Background and Objective: Heavy metals are toxic and can enter the food and thus the health of people who consume these kinds of foods may be affected. The aim of this study was to investigate the concentration of heavy metals in fruits and to estimate the exposure level of heavy metals by fruit consumption.
Materials and Methods: In this descriptive cross-sectional study, 60 samples (35 samples of apple fruit and 25 apricot fruit samples) were randomly collected from gardens around Zanjan and Mahneshan city in 2016. The concentration of Pb, Cd, Zn, and Cu were determined by atomic absorption spectrometer. Statistical analysis was done with SPSS software.
Results: The average concentration of the elements in the samples was as follows: Pb (0.121 mg/kg wet weight), Cd (0.052 mg/kg wet weight), Zn (10.63 mg/kg dry weight), and Cu (4.99 mg/kg dry weight). The average lead concentration in apple and apricot was, respectively, 0.17 and 0.057 mg/kg wet weight, cadmium 0.08 and 0.003 mg/kg wet weight, zinc 9.15 and 12.7 mg/kg dry weight, Copper 4.4 and 5.583 mg/kg dry weight. Furthermore, it was found that 28.3% of the samples were contaminated with Pb, 13.3% with Cd and 3.3% with Zn. Cu contamination was not detected above permitted concentration. The concentrations of heavy metals in Zanjan were more than Mahneshan and the concentrations of Pb and Cd in the apple samples were higher than the apricot samples but the concentration of Zn and Cu in the apricot samples were higher than the apple samples.
Conclusion: Heavy metals pollution was found in samples belonging to the gardens around the factories and mines of lead and zinc. However, there is no risk of non-cancerous diseases with the use of these fruits in accordance with the national standard declared per capita.
 

Background and Objective: Measurment of metals concentrations in scalp hair is a well known method for monitoring exposure to heavy metals, assessment of heavy metal poisoning, evaluation of nutrient levels and diagnoses of diseases. The present research was conducted to evaluate the concentrations of heavy metals in the scalp hairs of the local fishermen from Shif Island (Bushehr) and assess the effect of various factors on heavy metals levels in hair.
Materials and Methods: Thirty hair sampls were collected from fishermen of Shif Island. After sample preparation and chemical digestion, the heavy metals were analyzed by Atomic Absorption Spectrometer. The information required to evaluate the exposure was obtained via a questionnaire that was distributed among the fishermen.
Results: The concentration of Fe, Zn, Cu, Mn, and Ni were 72.79, 148.11, 8.6, 4.72, and 19.71 mg/kg, respectively. There were significant correlations among Zn, Mn, and Ni. In addition, the results showed that use of hair colour increased the metal concentrations.
Conclusion: Our findings recommend that the population of Shif area and neighbouring county may be exposed to some of these heavy metals, particularly Ni that is an industrial and oil pollutant. The most likely exposure pathways seemed to be fish consumption; however, more detailed studies should be performed.
 

Background and Objective: The aim of the present study was to investigate risk of heavy metals on human health including (Pb, Zn, Cu, Cr, Cd, Ni, V, As and Co) in street dusts in Abadan.
Materials and Methods: 30 dust samples were collected from sidewalks of main streets of Abadan and analyzed by inductively coupled spectroscopy (ICP-OES) method.
Results: The mean concentration of the heavy metals was as follows: Pb (59.13), Zn (287.50), Cu (112.97), Cr (50.30), Cd (0.52), Ni (56.77), V (35.83), As (10.7) and Co (7.33) (mg/kg). The concentration of all of the heavy metals, except V, in the dust samples was several times higher than the field concentration (concentration in the earth's crust). The average value of the potential ecological risk of the heavy metals V, Cr, Zn, Ni, As, Cu and Pb was low and had a low potential ecological risk. Cd had a moderate potential ecological risk. Also, based on the average value of Risk Index, the samples were at medium risk. Cumulative non-carcinogenic hazard of all the heavy metals in the street dust was higher for children than adults. This indicates that children are more at risk for heavy metals than the adults. In both age groups, Cr had the highest risk of carcinogenicity and Pb had the lowest risk.
Conclusion: The results indicated that the main source of the heavy metals in the study area is anthropogenic sources such as traffic, industrial facilities and burning of fossil fuels.
 

Background and Objective: Batteries can be hazardous to the environment and human health due to their toxic compounds. In this study, for detoxification and recovery of metals from spent coin batteries, a two-step bioleaching using Acidithiobacillus ferrooxidans was investigated.
Materials and Methods: A number of spent coin batteries were powdered. The powder was added to the bacterial culture medium and after 12 days the concentration of leached metals was determined. For investigating the effect of how to add the powder on metals recovery, the gradual addition of powder to the medium was carried out. For this purpose, the powder was added to the medium every 48 h at a rate of 20 g/L until the pulp density of 100 g/L. All experiments were run in triplicate and the standard deviation was shown as an error bar in the graphs.
Results: With an increase in pulp density, the metals recovery rate reduced. The highest recovery rates for lithium, cobalt and manganese was 100%, 88% and 20%, in pulp density of 40 g/L after 12 days. Leaching of lithium, cobalt and manganese was 66%, 8% and 0%, if the powder was added gradually until pulp density of 100 g/L.
Conclusion: The two-step bioleaching using Acidithiobacillus ferrooxidans was an appropriate method for recovery of metals from spent coin batteries. Also, gradual powder addition to the medium did not have a positive effect on the metals recovery and on improvement of bacterial growth characteristics. The metals recovery in high pulp densities was mainly due to chemical leaching.
 

Background and Objective: Water pollution due to heavy metals is a critical and increasing problem worldwide. In this study, removal of cadmium and lead heavy metals using a graphene oxide (GO) adsorbent was examined.
Materials and Methods: GO nanosheets were synthesized through Hummer’s method, and its characterizations were examined using FTIR, XRD, and SEM. The effect of independent variables pH, contact time and initial concentration of the solution on removal efficiency of Cd²⁺and Pb²⁺ using response surface methodology was evaluated according to Box-Behnken experimental design. Applying quadratic model, adsorption rate of Cd²⁺ and Pb²⁺ achieved 99%. ANOVA was applied for statistical analysis of responses.
Results: According to SEM images, the average size of graphene oxide sheets was 1 to 3 µm. After optimization through RSM, the adsorption capacity for Pb²⁺ and Cd²⁺ was 136 mg/g and 68 mg/g, respectively. Examination of the isotherms suggested that Cd²⁺ and Pb²⁺ adsorption follows Langmuir and Freundlich isotherm, respectively.
Conclusion: the results show that the graphene oxide performed well in removing both Cd²⁺ and Pb²⁺ ions from aqueous solutions. The most influential parameters on the above-mentioned heavy metals adsorption were pH of the solution and the initial concentration.
 

Background and Objective: The main objective of this study was to evaluate the surface and deep distribution of Pb, Ni and Cu in the wastewater-irrigated area of south of Tehran using GIS and Hydrus. It was expected to find a comprehensive information of heavy metals distribution and their accumulation in the soil. 
Materials and Methods: This study was carried out in wastewater-irrigated area of south of Tehran. Soil sampling from the top surface layer (0-15 cm) and wastewater channels was done. After sample analysis, ordinary Kriging method using different variogram in GIS was applied to explore the surface distribution of Ni, Pb and Cu heavy metals. Moreover, the deep percolation of heavy metals in the soil profile was simulated by Hydrus-1D in a duration of 210 days and the heavy metals concentrations in the soil were estimated.
Results: Exploration of the distribution of Pb using spherical model showed that the variation of this element was in the range of 20-70 mg/kg. This amount varied to 50-60 mg/kg for Cu and about 30 mg/kg for Ni. Moreover, the simulation of heavy metals deep percolation using Hydrus revealed that the most accumulation of heavy metals happened in the 0-15 cm soil surface layer and for deeper layer, this trend was descending.
Conclusion: Comparing the concentration of Pb, Cu and Ni with the maximum allowable amounts of WHO standards demonstrated that Pb concentration was more than the threshold limit. Finally, the applied models could simulate soil’s heavy metals content for both surface and deep distribution in the studied area.
 

Background and Objective: Street dust is an important factor in urban pollution which consists of soil, particulate matters and heavy metals. At present, over half of the world’s population lives in urban areas. Therefore, this study aimed to investigate health risks of heavy metals in street dusts in Zahedan.
Materials and Methods: The samples of street dust were collected in Zahedan. After preparation, the samples, were injected to ICP-MS for determination the amount of Hg and Cu. According to the measured concentrations, Hazard quotient (HQ) and hazard index (HI) were calculated to evaluate the health risk assessment.
Results: Results showed that Hazard quotient for both Hg and Cu was less than 1 for children and adult. HQ for Hg and Cu was in order of HQ_ingestion >HQ_dermal >HQ_inhalation> HQ_vapour for adults and HQ_vapour > HQ_ingestion > HQ_dermal > HQ_inhalation  for children. HI was also less than 1.
Conclusion: The value of HQ showed that inhalation of mercury vapor and ingestion were the main routes of exposure to Hg for children and adults. The non-carcinogenic risk was within the safe value (HI <1) in this study.
 

Background and Objective: The establishment of pelletizing and steel industries in Ardakan suburbs has increased the pollutants such as heavy metals into the environment. The purpose of this study was to investigate the contamination of the area soil by heavy elements around these industries using the pollution index (PI), comprehensive pollution index (NIPI), accumulation index (I_geo) and enrichment index (EF).
Materials and Methods: 57 soil samples were prepared by systematic-random sampling from 0 to 5 cm depth and levels of As, Cd, Cr, Mo, Ni, Pb, V and Zn were analyzed by ICP-OES.
Results: The highest and lowest mean of I_geo (0.49 and 0.36) and PI (2.16 and 1.17), were related to nickel, and the highest EF was calculated for Zn at about 25.1 and the lowest were detected for molybdenum approximately that was 17.1. The EF index of lead, vanadium and zinc, which was 15.8%, 5.3% and 1.8%, respectively, classified the study area in a medium enrichment class. Hot spots of lead, vanadium, nickel and zinc was at the nearest distance to these industries and downstream of wind direction.
Conclusion: Indicators of I_geo and EF showed a low level of soil pollution. The PI and NIPI indices in most stations were classified in medium pollution class, and the highest of these indicators was related to the surface soil of station 30, which was located near the steel industry. Therefore, it can be concluded that the activities of these industries had affected the soil contamination of the study area.
 

Background and Objective: Heavy metals contaminations are readily bioaccumulated in aquatic systems and lead to increased concentrations in food chains, posing a serious threat to human health, water-related organisms and aquatic ecosystems. The purpose of the present study was to determine the concentration of heavy metals in surface sediments of CheshmehKile River, to evaluate environmental and ecological risk and to determine the degree of contamination of the elements studied.
Materials and Methods: In this study, 25 samples of surface sediment were collected from the CheshmehKile River. The heavy metals content of the samples was measured by inductively coupled plasma-optical emission spectrometry. According to the content of heavy metals in sediment samples, environmental and ecological risk indices were calculated. Also, river contamination was evaluated by comparing the elements studied values with the sediment quality guidelines values.
Results: The mean concentration of chromium, manganese, iron, cobalt, nickel, zinc and arsenic were 41.27, 356.35, 16756.32, 9.17, 11.87, 41.24 and 24.60 µg/g, respectively. Based on the values of the CF and I_geo indices, all of the elements, with the exception of arsenic, showed a low degree of contamination. The indices of Eⁱ_r and RI also showed the lowest ecological risk at all stations.
Conclusion: The results of this study showed that the surface sediments of CheshmeKile River in Mazandaran province were somewhat contaminated with arsenic. However, fortunately, the river sediments were of good quality from the point of view of the content of chromium, manganese, iron, cobalt, nickel and zinc.

Background and Objective: Considering the toxicity, health and ecological hazards of heavy metals in the environment and the impact on organisms, it looks essential to measure and evaluate their concentrations at the various levels in indigineous ecological strctures. The present study evaluated the concentration of Lead, Nickel, Copper and Zinc and their ecological risk assessment in surface sediments of Sezar River in Lorestan province.
Materials and Methods: 16 stations along the Sezar River were selected for sampling. After preparation and acid digestion of the samples, the concentrations of these metals were determined by Atomic absorbtion.
Results: The average total concentration of the detected metals Ni, Zn, Cu and Pb in the sediment was 71.84 > 40.56> 7.75 > 5.61 mg/kg, respectively. In addition, the evaluation of the Potential acute toxicity, ecological risk, and Pollution Load Index represented a low pollution in the sediments. The environmental risk of the metals in the sediment was evaluated as: Ni> Pb> Cu> Zn. The findings showed that among metals, the contamination factor and modified hazard quotient (mHQ) for nickel was moderate and in the mediun to severe pollution level to the contamination, respectively.
Conclusion: According to the results, it can be concluded that Potential acute toxicity, pollution and ecological risk in the region for investigated metals were low. However, a rapid expansion of various human activities in the area and the pollution of nickel in the river along with the probability of its biological effects require continuous monitoring of the river in order to assess the health risk and its ecological risk.
 

Background and Objective: Environmental pollution emitted from industrial areas while enter the food chain can cause serious adverse health effects. Therefore, this study was conducted to use Ziziphus spina-christi and Prosopis cineraria leaves as bio-indicators of environmental pollution emitted from the complex of Steel Company.
Materials and Methods: In this descriptive study, a total of 90 surface soil samples and also 90 leave samples were collected. After acid digestion of samples, the heavy metal contents were measured using atomic absorption spectrophotometer. Also, the Bioconcentration Factor (BCF) of metals were computed. All statistical analyses were performed using SPSS statistical package.
Results: The highest content of the metals (mg/kg) with an average of 2180.3 ± 202.3 and 2237.9 ± 315.1 for Fe, 76.6 ± 9.6 and 114.3 ± 4.5 for Pb and 69.2 ± 16.8 and 107.2 ± 6.8 for Cd were found to be in Z. spina-christi and P. cineraria unwashed leaves respectively. Also, the BCF of all studied metals were higher than 1.
Conclusion: Based on the values of BCF, it can be concluded that Z. spina-christi and P. cineraria can be considered as a suitable species for phytoextraction of heavy metals in the most polluted regions including industrial and urban areas.
 

Background and Objective: Heavy metals enter to water resources through various ways, causing dangers such as illness, cancer, and, in general, a disorder in the body of living organisms. Mullet (Liza aurata) is highly consumed by the people living in Guilan province, Iran. Therefore, the amount of heavy metals included copper, zinc, and nickel was investigated in the muscle tissue of mullet.
Materials and Methods: A total number of 11 mullet were obtained from Bandar Anzali.  After a preparation step, the fish samples were digested using chemical digestion, and the amounts of heavy metals were determined by atomic absorption.
Results: The average concentration of copper, zinc, and nickel in muscle tissue was 10.07±0.93, 28.39 ±3.99, and 4.01 ± 0.55 μg/g dry weight, respectively. The concentrations of the studied metals were lower than the FAO, WHO, FDA, NHMRC and UKMAFF international standards, except for the nickel. The daily absorption rates of the studied metals (EDI) for children and adults were lower than the reference dose set by the EPA and the TI provided by the FAO / WHO Organization. The risk potential (THQ) of seven days, three days and one day consumption per week of Golden grey mullet for both adults and children were found less than 1. The hazard index (HI) of 7 days a week consumption of mullet for children was greater than 1.
Conclusion: According to the results of the present study, the consumption of this fish has a harmful effect on consumer health in children age group.
 

Background and Objective: Non-biodegradation in nature and creation of adverse health effects in humans is important features of heavy metals. The main objective of this study was to determine the level of contamination, carcinogenic and non-carcinogenic risks of falling dust containing heavy metals on residents around the industrial areas of Ardakan. Another objective was to identify potential sources of heavy metal release into the environment.
Materials and Methods: In this cross-sectional analytical study, the falling dust was collected in summer around Tile and Ceramic, Khak-e-chini, sand and gravel and glass industries by installing 35 Inverted Frisbee traps with artificial grass cover. The concentration of Cd, Ba, Cu, Ni, Cr, Mn and V were measured by ICP-MS. Probable sources of the heavy metal of the dust were evaluated using Pearson correlation coefficient and cluster analysis. Ecological risk indices for determining the level of contamination and proposed relationships proposed by the US Environmental Protection Agency were used to assess the carcinogenic and non-carcinogenic risks.
Results: The highest and lowest mean concentrations of heavy metals were measured for Cd and Ba, respectively. The results of Pearson correlation analysis and cluster analysis revealed three anthropogenic and also natural sources for heavy metals of the falling dust. According to the Ecological Risk Potential Index, Cd in 45.10% of the samples was in a very high class and in 54.88% of the samples was a high class. Pollution class of the ecological risk index of all the heavy metals was medium to high. The carcinogenic risk of Cr and Ba in children and adults was estimated to be higher than 10^–4. In both age groups, the Hazard index for each metal was less than 1 and its sum was measured as 1.29 for children and 0.16 for adults.
Conclusion: Cd increases the ecological risk of the falling dust in the area. Ther heavy metal carcinogenic risk results showed that the concentrations of Cr and Ba were higher than standard. Also, the non-carcinogenic risk was higher in children than in adults.

Background and Objective: Rangeland forage is the main source of feed for sheep and goats in many countries and the concentration of heavy metals in these plants is very important. Bushehr province is also affected by environmental pollution due to its proximity to the Persian Gulf, the occurrence of different wars and the existence of different oil and gas resources. The environment and rangelands, which feed on various livestock, are also exposed to these contaminants. Therefore, knowing the composition of the compounds and health of grassland forages will greatly help experts to better understand the health of meat and milk of animals that graze on these pastures.
Materials and Methods: Based on the rangeland area and the number of livestock in the coastal strip, two rangelands of Bashi and Rostami were selected and their grassland forage was randomly sampled. Plants were sampled at three grazing stages (first, middle and end of grazing season). Samples were dried in shade, then mixed and milled and sent to the laboratory.
Results: The results showed that the average of lead, cobalt, cadmium and chromium were 0.30, 0.15, 0.017 and 3.73 mg/kg dry matter in total rangeland, respectively. Significant differences were observed in the amount of cobalt element in the two study areas and the amount of other elements was not significantly different. The amount of cadmium was significantly different in the various stages of grazing, with the highest concentration in the first stage of grazing.
Conclusion: In general, the concentrations of these elements in the fodder of coastal rangelands of Tangestan area of Bushehr province were at permissible level for grazing animals. No risk of shortage or poisoning for the animals was observed and hence no danger to human health.

Background and Objective: Heavy metals contamination, particularly in aquatic environments, is an important concern.  Since Mahbad river is the source for supplying drinking water to the city and the dam established on it is used for catching fish and sale in the market, heavy metals concentrations in the sediments of Mahabad River and the Dam, and the possible health risk of the fish consumption were investigated.
Materials and Methods: Sediment samples from 21 sites in Mahabad dam, and river, and 16 fish samples (Sander lucioperca and bramis brama species) were collected. After preparation, the samples were analyzed using ICP-MS method. For data analysis, enrichment factor (EF), potential ecological risk index (RI), health risk indices, principal component analysis (PCA) and Mann-Whitney test were used.
Results: The EF and RI values of the studied heavy metals in the sediments were low. The max concentrations of lead, zinc, copper, arsenic and manganese were 36, 162, 74, 22.8 and 3221 mg/kg, respectively. This was more obvious in the samples taken from the downstream of the dam. However, accumulation of the heavy metals in fish tissues resulted in high values for total hazard quotients (THQ), particularly for As (1.19); high hazard index (above 1); and high estimated daily intake (EDI) for copper (1.64) in the study area.
Conclusion: The results of this study revealed that the conditions for elements’ mobility and bioavailability was suitable in the river and Mahabad Dam. Therefore, assessing the mobility and bioavailability of the heavy metals in the sediments of the region, and measurement and continuous monitoring of the heavy metals concentrations in the water, sediment and fish of the study area are needed.

Background and Objective: Application of sewage sludge contaminated with heavy metals may cause health and ecological concern. Ecological risk and heavy metals content of sewage sludge from wastewater treatment plants of East Azerbaijan province were evaluated in the present study.
Materials and Methods: Nine composite samples were taken and analyzed for heavy metals. The geo-accumulation index (Igeo), contamination factor(CF) , and potential ecological risk index were calculated.
Results: Variation of the heavy metals concentrations were in the following order: Zn>Cu>Pb>Cr>Ni>As>Hg>Cd. The contents of some heavy metals were several order of magnitude higher than the crustal average (CA) values. Considering the Maximum Permissible Standards (MPS) and the Muller's index, the Cd, Cu, and Zn pollution were found to be in the moderate range, whereas As and Pb were in strongly polluted category; and Hg was in extremely polluted category. Considering MPS, the single-factor pollution index (PI) and the Nemerow’s synthetic pollution index (PN) were lower than 1 and 0.7 respectively. This indicated that the sludges were unpolluted with most heavy metals and could be safely applied for agricultural uses. However, a high potential ecological risk for As and Cd; very high risk for Pb; and extremely high risk for Hg were calculated when considering the CA values. There were significant differences between the levels of heavy metals and MPS (p <0.05).
Conclusion: Although the metal concentrations were below the MPS according to the US EPA regulations, sludge samples showed a high degree of potential ecological risk for the environment in comparision with the CA values,. Periodic monitoring of sludge quality are strongly recommended.  

Background and Objective: 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.
Materials and Methods: 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.
Results: 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.
Conclusion: 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.