Iranian Journal of Health and Environment

Ecological risk of heavy metals in surface soils of urban parks

S Sobhanardakani

Background and Objective: Heavy metals are the most frequent pollutants of urban soils. In general, human health and especially children are directly at risk if the soil is being accidentally ingested orally or nasally. Therefore, this study was conducted to assess potential ecological risk index (RI) of Pb, Cd, Cr and Cu in surface soils of urban parks in Tehran City in 2016.
Materials and Methods: A total of 60 surface soil samples were collected from Mellat, Laleh, Velayat, Ekbatan and Pirouzi parks. The heavy metals contents in samples were determined using ICP-OES after acid digestion of soil samples. Also, RI of heavy metals was determined. All statistical analyses were performed according to the Shapiro-Wilk test, One-Way ANOVA, One Sample T-Test and Pearson Correlation Coefficient.
Results: The lowest and highest contents of the metals (mg/kg) with an average of 0.52 ± 0.25 and 153.81 ± 31.83 were related to Cd and Pb, respectively. Pb and Cu were higher than MPL. Also, the highest surface soil contamination was related to Velayat Park located at the south of Tehran. The value of RI was 99.16 and therefore the soil contamination was categorized in low ecological risk.
Conclusion: Although the value of RI categorized as low ecological risk, due to mean concentrations of Pb and Cu were higher than MPL, control of soil-contamination sources, periodic monitoring of surface soil in the urban parks where citizens spend most of their free time. Additionally, it should be avoided to construct urban parks close to the regions with high traffic intensity.

Catalytic degradation of Triclosan by using xenon light/GO @ TiO2 combination system: optimization of initial parameters

K Yaghmaeian

Background and Objective: Triclosan is one of the substances as anti-microbial that is used in many of these pharmaceutical products. This compound can affect human such as reduction of thyroid hormone levels, antibiotic resistant, and increasing skin cancer. This study evaluated the performance nanophotocatalysis process UV/Xe/TiO₂-GO on triclosan removal from aqueous solutions.
Materials and Methods: Synthesis of TiO₂@GO and its structure was analyzed by SEM, EDX and FTIR. The effects of pollutant concentration, catalyst dosage, and contact time on the removal of Triclosan were studied by DOE software according to response surface methodology. Analysis of variance test was considered for the influence of parameters. Optimum process condition was determined by desirability factor.
Results: Optimum conditions regarding concentration of pollutant, contact time, and catalyst dosage were determined as 0.205 g/L, 14.898 min, and 0.487 mg/L, respectively. Maximum removal efficiency in optimum condition was 97.542 percent. The catalyst dosage was the most effective parameter in removal of Triclosan.
Conclusion: Using of TiO₂@GO and xenon lamp had acceptable efficiency for the removal of Triclosan. The use of Xenon lamps alone was economically affordable.

Analysis of pollution of jobs: a case study in city of Qom in 2016 year

A Eskandari

Background and Objective: Today, workshop industries play an important role in urban development by creating effective employment in urban areas. It has been stated that these small industries can cause environmental pollution. The purpose of this study was to investigate and analyze the contaminations caused by the workshops in Qom in 2016.
Materials and Methods: The present study was descriptive-analytic-cross sectional. First, all of the city's businesses were listed in 67 relevant :::::::union:::::::s. After identifying the polluting businesses, a total of 223 classes of all :::::::union:::::::s were randomly screened. Sewage, solid waste, air, sound, soil and landscape pollution were investigated. According to 15 specialists and using Expert Selection software, each pollution type and rating of each class were weighed and determined.
Results: The results showed that the wastewater, solid waste, air, noise, and landscape pollution with a score of 0.399, 0.259, 0.169, 0.097, and 0.027, respectively, are important. Accordingly, in terms of the total contamination of the studied occupational units, authorized dealers of car sales, carwash, guest house, carpet cleaning, bath, brick plants, chalk plants, gemstones, chelokbaby, mosaic making, lathes and blacksmans, iron doors and window making, general blinds and shuttering, ceramic making, wood processing industry, mechanical, polishing with a total score of 1, 0.889, 0.881, 0.872, 0.709, 0.644, 0.644, 0.641, 0.62, 0.609, 0.582, 0.569, 0.552, 0.546, 0.518, 0.499, and 0.499 had unfavorable status, respectively.
Conclusion: In order to reduce the environmental pollution caused by these businesses, continuous monitoring and inspections should be carried out in the short term. Moreover, the polluting industries should be relocated out of the city in the long term.

Comparative study of the performance of chitosan and chitosan adsorbents modified with Fe3O4 to eliminate erythromycin from aqueous solutions

E Asrari

Background and Objective: Excessive consumption of antibiotics and the entrance of the potentially hazardous substances to the environment has become one of the environmental concerns. Today, adsorption is one of the efficient and reliable methods for the removal of this class of compounds. The aim of this study was to synthesize chitosan-Fe₃O₄ and to compare the efficacy of removing erythromycin antibiotics from aqueous humorous media by this adsorbent and chitosan.
Materials and Methods: The structural properties of the synthesized adsorbent were analyzed by TEM, PSA, VSM techniques. Various parameters including pH (1-11), contact time (0-60 min), adsorbent concentration (1-5 g/L), and initial concentrations of erythromycin (5-50 mg/L) was evaluated for the removal efficiency. For data analysis, Excel software was used. The equilibrium constant and the kinetic constants were calculated from the first-order kinetic model using Freundlich and Langmuir isotherms.
Results: The results indicated that increased pH and initial concentration of erythromycin increased the dose of adsorbents and the contact time of removal efficiency. The highest absorption efficiency at pH of 3 for both adsorbents, the contact time 30 min for modified chitosan and 50 min for chitosan, the dose of adsorbent 2 g/L for modified chitosan, and 3 g/L for chitosan and the initial concentration of erythromycin for each of the two adsorbents was 10 mg/L and the erythromycin adsorption by both adsorbents follows the Langmuir isotherm and the pseudo second order kinetics.
Conclusion: According to these results, chitosan modified with Fe₃O₄ can be used as a more effective adsorbent than chitosan for removal of erythromycin by adsorption method.

Optimization of activated carbon production by using K2CO3 at different temperatures for the removal of Reactive Black 5 dye from aqueous solutions

H Younesi

Background and Objective: Reactive dyes are the newest dyes in textile industry. They may cause environmental problems. The aim of this study was to remove Reactive Black 5 (RB5) in aqueous solutions with activated carbon that was made from grape wood.
Materials and Methods: The activated carbon was synthesized by potassium carbonate with impragnation ratios of 1:0.25 at different temperatures (600,650,700,750,800,850,900)^°C. Experiments on dye adsorption were done under the same conditions including pH of 2, adsorbent dose of 0.025 g/L, initial dye concentration of 250 mg/L, volume of 100 mL, and contact time of 120 min. Then, the absorption RB5 in a bathc mode was done using the optimized activated carbon. The trends of pH, absorbent dose, initial concentration, temperature, retention time, parametrs were studied. The BET and SEM techniques were used to characterize the activated carboon. Finally, the equilibrium, synthetic and thermodynamic studies were done for RB5.
Results: The results showed that the activated carbon sample that was synthesized under the imprenation ratio of 1:0.25 and temperature of 900 ^oC had a surface area 1670 m²/g. Moreover, the total pore volume was 1.134 cm³/g and 68% of the total pore size were within mesoporous zone. The highest adsorption capacity was observed at the optimum condition. The optimum condition with the maximum adsorption capacity for RB5 was pH of 2, adsorbent dose of 0.035 g/L and temperature 45 °C. According to the equilibrium test results RB5 followed the Freundlich model. of the kinetic adsorption results showed that RB5 showed a pseudo-second-order kinetic model. According to the thermodynamic studies, it seems that RB5 absorption process was an endothermic, non-spontaneous and physical sorption process.
Conclusion: The study showed that the produced-activated carbon from grape wood had a great potentioal for removing RB5 from aqueous solutions.

Determination of peroxide value of edible oils used in sandwich and falafel shops in Tehran

GR Jahed Khaniki

Background and Objective: Hydrogen peroxide is one of the compounds that is primarily produced by the oxidation of oil and fat and causes various diseases, including atherosclerosis and coronary artery disease .The aim of this study was to survey the peroxide value of edible oils used in sandwich and falafel shops in Tehran in 2016.

Materials and Methods: In this study, sampling from a number of fast food centers was done randomly. After the transfer of samples to the chemistry laboratory of environmental health engineering department, the peroxide number was determined based on the national standard procedure 4179. The data was analyzed by SPSS software for descriptive statistical parameters and t-test.

Results: According to the National Iranian Standards, from total of 50 samples of the sandwiches taken, 20 samples (40 %) were consumable and 30 samples (60 %) were inedible. Also, from 40 samples of falafel taken, 14 samples (35 %) were consumable and 26 samples (65 %) were inedible. The maximum peroxide values of sandwiches and falafel were 29.79 and 31.22 meq/kg, respectively.

Conclusion: The findings show that Peroxide value in the sandwich and falafel shops were higher than the standard, and thus it seems that having an educational plan for staff regarding the correct methods of frying food is necessary.

Assessment of rainfall heavy metals in the Bojnourd urban watershed

H Izanloo

Background and Objective: Important information can be obtained about the sources of pollutants in the atmosphere by studying the concentration of heavy metals in atmospheric precipitation.. Therefore, in this study concentrations of Pb, Zn and Cu were measured in samples of urban watershed of Bojnourd in autumn and spring seasons to help urban managers to control pollution in Bojnourd area.
Materials and Methods: This study was a descriptive and cross-sectional research. 24 samples of rain water were collected to measure heavy metals. The amount of heavy metals in the samples was measured using atomic absorption.
Results: Results showed that the pH was alkali in the Bojnourd urban watershed. Concentrations of Pb, Zn and Cu in rainwater in both autumn and spring were compared to international standards of WHO and EPA. The difference was significant (P <0.05) and was less than the standards values. Also, the results of the Pearson correlation test showed that the highest positive correlation was between zinc (r = 0.733) and copper (r = 0.190) in the samples of autumn and spring. This correlation was approved using hierarchical cluster analysis method.
Conclusion: The low levels of pH and low concentrations of heavy metals in comparison with global standards indicated low rainwater pollution to heavy metals. Thus, there is no a health threat to the people of the city. The concentration of heavy metals in the metropolitan area of urban watersheds had been higher than other basin levels and the most dominant contaminant was lead in the residential and commercial areas with the highest urban traffic. The pollution to heavy metals varied in different seasons and the value was higher in spring rainwater samples than the autumn ones.

Determination of heavy metals in apples and apricots in Zanjan and Mahneshan gardens in 2016

N Khodamoradi Vatan

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.

Ozone estimation on the ground surface using multivariate linear regression and parameter determination

AA Kakroodi

Background and Objective: Ground level ozone (O₃) is one of most dangerous pollutants for human health in urban areas. The aim of this study was to identify the factors affecting the formation of ozone and modeling the spatial and temporal variations of ozone concentration in Tehran metropolitan area.
Materials and Methods: The data used in this research included meteorological data and pollution concentration data for 2014. First, we studied the impact and correlation of parameters to ozone concentration using the coefficient of Pearson, and then we did modeling of ozone concentration using a multivariate linear regression method.
Results: The developed model had the ability to describe 79% of the data changes for 2014. The temporal analysis of the ozone concentration showed that the best coefficient of determination of the model was R² = 0.771 in the summer and R² = 0.778 in July. These results also showed that among the air quality monitoring station of Tehran, station 4 had the lowest coefficient of determination (R² = 0.6) and Aqdasieh station had the highest coefficient of determination (R² = 0.79). Finally, the spatial distribution of the estimated ozone concentration was consistent with the measured ozone concentration at the station level.
Conclusion: According to the results, all the parameters related to air pollution concentration and meteorological parameters were effective parameters on modeling of ozone concentration on the ground level. The spatial distribution of ozone concentration in Tehran showed a greater concentration of ozone in the South and East than the North and West of the city.

Monitoring of groundwater quality changes trend in four plains of Gilan province during a 12-year period

M Bayatvarkeshi

Background and Objective: Drought and water shortage in recent years caused rice farmers to use maximum groundwater as a secure source. However, the rice is affected not only by the quantity but also by the quality of water. The purpose of this study was to evaluate trend of quality parameters of groundwater in wet and dry periods in 4 plains including Astaneh, Talesh, Lahijan and Foumanat, which are all located in Gilan province.
Materials and Methods: In this investigation, data was collected for quality parameters from 15 groundwater of the 4 plains of Gilan province from 2003 to 2014. The data was collected from 15 piezometer wells of Astaneh, 41 piezometer wells in Talesh, 24 piezometer wells in Lahijan and 44 piezometer wells in Foumanat. For each well, two time series of 15 quality parameters in wet and dry periods were created in SPSS software. The trend was evaluated by Mann- Kendall test that is a nonparametric method.
Results: The results showed that in both periods, the trend of most quality parameters was declined, However, the quality decline in wet period was more severe. In both periods, the pH and Na % were increasing. Additionally, in dry period, the increasing trend of SAR and SO₄ was observed. Overall, the water quality of wells in Talesh plain for cultivation of rice was better than the other plains.
Conclusion: Consumption of groundwater of all the plains in both wet and dry periods for agricultural purposes and especially rice cultivation was without limitation. According to the decreased concentration of the measured parameters during the studied period, it can be expected that groundwater quality of Gilan province plains has been improved.

Assessment of the quality of groundwater for drinking purposes in Varamin aquifer: heavy metals contamination

Z Nejatijahromi

Background and Objective: Irrigation of agricultural lands with treated wastewater in the main part of the Varamin plain, the highly populated urban areas of the middle part of the plain, and the presence of industries have increased the actual risk of heavy metal contamination of groundwater. Therefore, the concentrations of heavy metals were investigated in this study in order to assess the risk of using groundwater of Varamin aquifer for drinking purposes.
Materials and Methods: A total of 78 groundwater samples were collected to measure the concentrations of Cu, Pb, Zn, Cr, Cd, Fe, Co, and Mn ions. The bivariate correlation analysis has been used to describe the correlation between hydrochemical parameters in the Varamin area. Heavy Metal Evaluation Index (HEI) and Heavy Metal Pollution Index (HPI) of the groundwater were determined to determine the feasibility of drinking supply in Varamin plain.
Results: The average concentrations of cadmium in dry and wet periods were 7.5 and 8 μg/L, respectively. In the wet period, the average concentration of lead in the groundwater of the Varamin plain was 12.5 μg/L. The concentrations of both heavy metals were more than the permissible amount for drinking. Pearson correlation analysis of qualitative data of the water samples of the Varamin plain showed a strong correlation between some heavy metals such as Pb and Co with Cd, Cu and Mn. This reflected a similar source of contamination of the groundwater, inter-correlations, and the same mobility behaviors in the aquifer media. The results obtained from HEI and HPI showed that the pollution of Varamin aquifer in most parts was not dangerous with respect to the heavy metals concentrations, but in some areas, significant variations in the concentrations of some metals can be observed.
Conclusion: It may be expected that the risk of groundwater contamination continues with respect to heavy metals due to the persistence of contamination sources in the Varamin plain. Hence, some measured should be taken with regards to the agricultural recycle water, dispose of domestic and industrial wastewater, and the quality of transferring treated effluent from Tehran to the plain.

A systematic review on drinking water resources-related studies in Iran: identification of research gaps

M Hadi

Background and Objective: Supply of safe drinking water to each community is one of the most important challenges in improving the general community’s health. Considering the importance of the research on water quality, identification of water quality research gaps was performed by reviewing the relevant studies through a systematic review for Iran.
Materials and Methods: In this study 638, 166, 300 and 1000 relevant articles were found on Scopus, SID, Magiran and Iranmedex databases, respectively. Out of 2104 articles, 1394 articles were excluded from the study. Finally, 710 articles were further reviewed.
Results: Monitoring of pollutants by a descriptive study was the main objective of the most studies (36.62%). Around 13% of the studies were performed on a laboratory scale. Organic pollutants in Iran have been concerned only in 17 provinces, and other provinces have not participated in this regard. Nitrate is studied in around one fifth of the total studies. Heavy metals were also considered as a parameter of concern in the studies carried out on monitoring drinking water resource quality.
Conclusion: This study reflects the research gaps and provides a basis for prioritizing water quality research in Iran. More actions and sound planning should be taken to monitor organic and inorganic pollutants. Chemical and microbial risk assessment, tracing the fate of pollutants and assessment of their ecological effects, investigations on advanced water purification processes, the use of bioremediation methods, identification of biological contaminant using biomarkers and molecular identification techniques are the most important research priorities that require more investigations.