Showing 58 results for Air
M Khalaji, Sa Hiseini, R Ghorbani, N Agh, H Rezayi,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Nutrient-rich effluents (mainly nitrogen and phosphorus) may lead to algae blooms and many harmful effects in aquatic environments. Micro-algae have been more effective among the various methods used for the removing of nutrients from wastewater. Microalgae Chlorella vulgaris has specific characteristics such as rapid growth, resistant to systems manipulation, simple and inexpensive production technology, as well as the rapid uptake of nutrients such as phosphate and nitrate.
Materials and Methods: In the present study, two concentrations of chlorella vulgaris microalgae (13 and 26 million cells/mL) were injected into dairy effluent, diluted using distilled water by 25, 50 and 75%, and the amount of nutrient removal and microalgae growth were examined during the growth period.
Results: Results indicated that different concentrations of algae at various percentages of dilution (25, 50, 75%) had a significant effect on the removal of nutrients and algal growth (p<0.05). The absorption of nutrients (nitrate, phosphate and ammonia) were 57.01, 51.84 and 43.15 percent respectively that containing lower density of initial algae compared to the treatments of 2nd group (29.15, 51.84 and 43.15 percent) with higher algae concentration. In both algal concentrations, the highest percentage of phosphate and ammonia adsorption were in dilution of 25% effluent and the highest percentage of nitrate adsorption were in the first group with 50% dilution and in the second group with 75% dilution.
Conclusion: The more percentage of nutrients (nitrate, phosphate, ammonia) was eliminated compared to the second group (26 million cells / mL) when the microalgae concentration (group I) was 13 million cells / mL. Absorption of nutrients was decreased by increasing the concentration of microalgae. Regarding to the percentage of nitrate adsorption, the higher absorbance in the dilution was occurred at the highest concentration of algae.
A Ahmadi Orkomi, A Kamkar, Z Aghajani,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Since mobile resources are the most important sources of air pollution in the metropolis of Rasht and due to the importance of air pollution in wet weather condition in Rasht, this research was carried out in a specific area to determine the pattern governing the change in the monthly emissions of pollutants on a small scale, using the results obtained from that area.
Materials and Methods: In this study, the amount of air pollutants was estimated on a small scale by continuous monitoring of traffic throughout the year (four days per month and six hours per day) and using MOVES software.
Results: The maximum annual average emissions of CO and NOx in the study area were 15.76 (between Gas and Razi squares) and 2 (between Imam Hossein Square and Nirou Daryaee square) g/(m.hr), respectively. In addition, the results showed that the average monthly emission of NOX throughout the year in each of the sections was constant and the average monthly emission of CO in the first half and the second half of the year was constant, and its value in the first half was higher than that in the second half.
Conclusion: Hourly distribution of CO emission in different months was affected by events and, in general, the pattern of people's life styles. But the hourly distribution for NOX was roughly constant throughout the year. Also, according to the results, with a single measurement (for CO) and twice measurement (for NOX) of traffic instead of monthly measurements, the pollutant emission estimation in other parts of the city was possible with an acceptable accuracy. Because the generalization of the method used in this study to estimate the emission of pollutants in all roads of the city is not reasonable and cost-effective.
R Bayat, Kh Ashrafi, M Shafiepour Motlagh, Ms Hassanvand, R Daroudi,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Despite the significant improve in air quality in Tehran in 2018 and reducing the average concentration of most pollutants, compared to previous years, air quality is still far from the WHO air quality guideline level and national air quality standards. The purpose of this study was to estimate the effects of air pollution on health in Tehran by considering the spatial distribution of particulate matter 2.5 micrometers or less in diameter (PM2.5) and population in determining exposure levels.
Materials and Methods: In this study, while introducing the GEMM concentration–response function and BenMAP-CE software, the mortality attributed to PM2.5 in Tehran and its distribution for 2017 and 2018 was calculated. Hourly PM2.5 from monitoring stations used to estimate the mean PM2.5 for 349 Tehran neighborhoods.
Results: The results showed that the average population weighted PM2.5 concentrations in Tehran in 2017 and 2018 was estimated to be 31.8 and 26.2 µg/m3 respectively. Using the GEMM function, about 7,377 (95% CI: 6,126-8,581) total mortality attributed to PM2.5 was estimated in adults in 2017 (> 25 years) and the figure for 2018 was estimated as 6,418 (95% CI: 5,918-6,753).
Conclusion: The spatial distribution of deaths attributable to PM2.5 showed that the total mortality rate per 100000 in the districts 16 and 18 of the Tehran municipality were higher than other districts and the lowest rate observed in the district 1.
M Ghannadnia, Mm Zarrabi, N Habibi,
Volume 12, Issue 4 (2-2020)
Abstract
Background and Objective: Air pollution, especially the portion related to Motor vehicles, is a serious problem in many heavily polluted areas in the world. This investigation was conducted to study the effects of the air pollution on the anatomical structure of leaf in some valuable fruit-bearing trees in Traditional Qazvin gardens.
Materials and Methods: In this study, 72 leaf samples were randomly collected from the contaminated and control areas from traditional Qazvin gardens in 2018. Three leaves of each sample were selected randomly and were submerged into the fixative solution. Then the samples were sliced using a microtome after embedding in the paraffin. Staining was carried out with hematoxylin and eosin. Measurements at cellular levels were performed by Image J. Data were analyzed by SPSS 16 software. Comparison of the means was done by Duncan's test and the charts were drown using Excel.
Results: The thickness of the lower cuticle of the main leaf's vein was significantly increased in both plants. The leaf thickness and length of palisade parenchyma in the polluted areas were increased in Juglans regia in comparison to Pistacia vera. In addition, the resin duct's diameter of the leaves of the P. vera was significantly decreased as compared with those of the control areas.
Conclusion: The results revealed some of the negative effects of air pollution on the anatomical structure of the leaves, and on several various resistance mechanisms of them. In conclusion, the metabolism of the plants can be affected by air pollution and consequently their consumers health may be at risk.
Ali Ahmadi Orkomi, Melika Mirchi,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: Since people spend a lot of time indoors, assessment of Sick Building Syndrome (SBS)is the first step to improve working and living conditions in closed environments. This study wasconducted to evaluate the SBS symptoms among staff in Razi Hospital of Chalous, to identify the affecting environmental parameters on these symptoms and to provide solutions to reduce the symptoms of SBS.
Materials and Methods: This descriptive-analytical study was conductedrandomly among 72 out of 240 hospital’s staff. Questionnaire MM040EA was used to collect demographic data, SBS symptoms and affecting environmental factors. Statistical analysis was carried out using Pearson’s Chi-squared test and Fisher's exact test in Excel software.
Results: 60% of people showed moderate to severe SBS symptoms. Fatigue, headache, and sneezing were the most common symptoms among staff, with 85%, 75%, and 63%, respectively. Significant correlation was observed between SBS symptoms and room temperature fluctuations (p <0.001), low ambient temperature (p = 0.037), unpleasant odor (p = 0.043) and gender (p = 0.011) with significance level of α=0.05.
Conclusion: Investigating the influence of work environmental related factors on the general symptoms of SBS as well as on fatigue, headache and sneezing symptoms showed room temperature fluctuation and unpleasant odor as the most important driving factors. These symptoms were mainly due to the improper air conditioning system operation at the hospital to control the temperature. Therefore, it is expected that the prevalence of SBS among staff can be reduced significantly by improving the ventilation system performance, especially in winter.
Behnam Nazari Alamdarloo, Asghar Mosleh Arany, Saeed Shojaee Barjoee, Hamidreza Azimzadeh, Bahman Kiani,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: Urban traffic, while affecting human health, causes physiological and biochemical changes in plants. The aim of this study was to investigate the bioaccumulation potential of Pb and Cd and assess air pollution tolerance index for a number of plants grown high traffic areas of Yazd.
Materials and Methods: This cross-sectional, descriptive-analytical study was performed in both control and high traffic areas of Yazd city by random sampling of trees, shrub and herb species. After transferring the samples to laboratory, relative water content, pH of leaf extract, total chlorophyll and ascorbic acid content (the factors for calculating APTI) in plants were measured using standard methods. Furtheremore, Pb and Cd concentrations were measured to find their relation with APTI index in plants. All statistical analysis, including Kolmogorov–Smirnov test, ANOVA, Duncan test and Pearson correlation coefficient between the studied parameters, were performed in SPSS software version 22.
Results: The highest relative water content (84.73%) and ascorbic acid (5.98 mg/g) were measured in contaminated area for Canna indica and Rosa damascena, respectively. Also, the highest acidity (7.01) and total chlorophyll (1.48 mg/g) in the control area were measured for Verbena hybrida and Ligustrum vulgar, respectively. The highest air pollution tolerance values were recorded in Rosa damascena and Ligustrum vulgar. Moreover, the results obtained showed that APTI index was positively and significantly correlated to Pb, ascorbic acid and relative water content.
Conclusion: According to the classification of air pollution tolerance index, two species of Rosa damascena and Ligustrum vulgar exhibited moderately tolerant to traffic pollutant. Therefore, based on ecological requirements of these two species, they can be used to develop green spaces in high-traffic areas of Yazd. This study showed that Pb increased physiological response of the studied plants, while the plants did not exhibit a significant physiological response to the Cd element. The results also showed that the relative water content and ascorbic acid were more important in the air pollution tolerance index than other factors.
Mazaher Moeinaddini, Seyed Hassan Mousavi, Zohreh Isakhanbeygi, Somayeh Heidari,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: One of the most important goals for urban environmental management system is the monitoring of air quality. Allocating optimum air quality monitoring stations (AQMS), is a key factor in establishing effective and accurate air quality monitoring program. The objective of this study was to determine optimal allocation for AQMS in Karaj.
Materials and Methods: Based on two stages approach, at first, the suitability map was obtained by WLC method. For AQMS implementation, municipal districts were ranked. The extracted alternatives were graded using TOPSIS. In the next stage, the position of preferred sites were investigated by site visiting and detailed criteria. Finally, the AQMS locations were introduced.
Results: Ten suitable stations were suggested based on population and number of municipal districts. During the first stage important criteria such as distance from roads and street cross-section were weighted and standardized. The distance from roads and green space were the lowest and highest important criteria, respectively. The lowest and highest ranks for AQMS implementation were Nos. 9 and 3 districts, respectively. During the first phase 30 alternatives were obtained. At the second stage, 10 best alternatives were selected following field observation and considering implementation criteria (eg. distance from trees, cross section and pollutants emission sources).
Conclusion: In this study, at the first stage the preferred alternatives were determined. In the next stage the best alternatives for AQMS implementation were selected considering reasonable time and effort. The suggested approach could be used to implement AQMS for other areas.
Sara Manochehrneya, Mitra Mohammadi, Reza Esmaeili, Ahmad Vahdani,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: This study aimed to evaluate the correlation between climatic parameters and air pollution with cardiovascular disease and its associated death during 2014 in Mashhad by time series model.
Materials and Methods: Patient data (including outpatient and hospitalization) and cardiovascular mortality were obtained from the emergency medical center and Ferdowsi organization of Mashhad. Climatic parameters such as temperature, pressure, relative humidity, wind speed, and rainfall were gathered from meteorological organization. Air pollutants data were collected from Mashhad environmental pollutants monitoring center for the statistical period of 2014-2015. In this study, Jenkins Box time series model (combined model of autoregression and moving average known as ARIMA) with significance level of 5% was used to investigate the effect of climatic parameters and air pollution values on cardiovascular disease and daily, weekly and monthly excess mortality rate. Then, the effect of various seasons on the total number of patients with cardiac issues and the resulting death was investigated by Kruskal-Wallis nonparametric test.
Results: The final model for determination of monthly correlation between climatic elements and air pollutants with the number of cardiovascular patients and its corresponding death was found to be best fitted by ARIMA (0,0,0). The monthly survey revealed that humidity (positive correlation), temperature (positive correlation), wind speed (negative correlation), and PM2.5 (negative correlation) with average values of 16.2471, 48.1628, 122.38, and 7.3905, respectively, had significant effects on the number of people experiencing cardiovascular disease. However, the monthly survey of mortality rate due to cardiovascular disease exhibited significant correlation (p < 0.05) with pressure (positive correlation), temperature (negative correlation), and rainfall (negative correlation) with average values of 6.5904, 1.5728, and 1.1704, respectively. The results showed a significant difference between the numbers of patients experiencing cardiovascular diseases in different seasons of the year with the highest recorded number of 3778 in autumn.
Conclusion: The results suggest moderate correlation between atmospheric elements and air pollutants with the numbers of people experiencing cardiovascular diseases in short periods; however, in the case of long-term mortality, the correlation was strong. This study showed that climatic elements and air pollutants effectively affect cardiovascular diseases, while only climatic elements played a significant role in mortality. The main challenge of the present study is that cardiovascular disease and its resulting death may be influenced by parameters other than those considered in this study, such as multiple individual and environmental confounding variables.
Hossein Kamani, Mohammad Sadegh Hassanvand, Abdolali Khammari, Sadegh Haghighat,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Air pollution is one of the most important environmental risk factors that exposure to it can cause many acute and chronic effects on human health. Some regions of Iran, especially the western, southern and southeastern provinces of the country, have been affected with dust storm for years. Studies on the frequencies of dusty days in the country show that central pits of Iran and the cities of Zabol and Zahedan have the highest incidence of dusty days. The purpose of this study was to determine the concentration of suspended particles with aerodynamic diameter of 2.5 μm or less (PM2.5) in various seasons and months during 2019 in Zahedan.
Materials and Methods: In this descriptive-analytical and cross-sectional study samples were typically collected once every 6 days during a 24-hour period as well as on dusty days using an air sampler (PQ200 / BGI) from July 2018 to July 2019.
Results: The results show that the mean concentration of PM2.5 in Zahedan during this study was 36.86 µg/m3. The maximum and minimum PM2.5 daily concentrations in the sampling days were also measured as 130.8 and 4.75 µg/m3, respectively.
Conclusion: In conclusion, 88% of samples contained PM2.5 concentration above the WHO 24-hr air quality guideline level (25 µg/m3), which could be due to the high incidence of summer dust storms. This indicates that particulate matters are a serious health threat to people living in those areas and calls for the implementing measures to tackle the problem.
Mohammad Sohrabi, Nasrin Hassanzadeh, Fariba Hedayatzadeh, Mehdi Mofid,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Air quality and distribution of trace elements in the Tehran metropolis were evaluated using transplants of the epiphytic lichen Ramalina sinensis.
Materials and Methods: Thalli of R. sinensis were collected from a non-contaminated area and transplanted in the six urban sites of Tehran for six months. After the end of the exposure period, the content of twelve elements in lichen was determined by ICP-MS method and the obtained data were evalusted using statistical analysis and various indicators.
Results: Based on the results, the order of mean concentration of the trace elements in the R. sinensis lichen samples was determined as: Ca > K > Fe > Mg > Na > Mn > Zn > Pb > Cr > Cu > Ni > Co and the highest amount of bioaccumulation was found for the essential elements. For sevelar elements, significant differences were observed in various sampling sites. Based on the pollution load indexes (PLIs), two sites at Sharif university and Setad Bohran were more polluted than other areas. Exposed-to-control (EC) ratio values for Pb, Zn, Cr, Fe, Mn, Ni, Mg, and Co were also found in the range of 1.25-1.75. Based on the relative accumulation factor (RAF), the accumulation preference of elements by R. sinensis lichen was observed as Na > Cr > Cu > Fe > Mg > Ni > Zn > Mn > Co > Pb > Ca > K, respectively, which represents the significant ability of this species in the accumulation of elements such as Na, Cr, Cu and Fe. PCA and EF analysis indicated that trace elements adsorbed by lichen were mainly sourced from vehicle transportation.
Conclusion: This study demonstrates the application and importance of R. sinensis lichen in biomonitoring of air pollutants elements in urban areas. This approach can justify the suitability, accuracy and cost-effectiveness of lichen compared to other biomonitors for air pollutants and more importantly highlights its capability to the determination of wide levels of air pollution in large scales.
Faezeh Kamal, Reza Fouladi Fard, Azam Sabahi Hoveida, Zabihollah Gharlipour, Nayereh Rezaie Rahimi,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: The most important first step in promoting environmental performance is identifying and evaluating environmental behavior. In this regard the measuring tool is considered an environmental behavior questionnaire. Validity and reliability of the questionnaire before its application is essential. Thus this research was conducted with the aim of assessing the validity and reliability of questionnaires.
Materials and Methods: The environmental behavior questionnaire containing 36 questions was designed using the literature review and expert panel opinions. Then, the validity of the questionnaire was assessed by content validity index (CVI) and content validity ratio (CVR) and its reliability was evaluated using Cronbach's alpha coefficient by 14 experts and 40 target groups. Finally, data were analyzed by SPSS 20 software.
Results: The results showed that the questionnaire with 36 items had CVI and CVR of 0.896 and 0.726, respectively, and 4 items should be excluded from the questionnaire due to non-compliance with content validity indices. The questionnaire exhibited high internal consistency and hence was acceptable owing to the Cronbach's alpha coefficient of 0.85.
Conclusion: The questionnaire was designed to evaluate environmental performance of citizens and can be cited in future studies.
Moslem Rahimi, Maryam Mohammadi Rouzbahani, Khoshnaz Payandeh, Ahad Nazarpour, Ebrahim Panahpour,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: Due to the spread of dusty air and the transfer of these particles to the cities of Khuzestan province, it is very important to study the status of these particles in terms of heavy metal pollution and their pollution status.
Materials and Methods: In this study, the concentrations of Cr, Cu, Zn, Pb, Ni, Mn, Mg and Fe in the air of 4 cities of Khuzestan province (Ahvaz, Dezful, Mahshahr and Abadan) in dusty and dust-free conditions over a period of 9 months (autumn, winter and spring) were measured in 2018-2019. Due to the spread of dusty air and the transfer of these particles to the cities of Khuzestan province, it is very important to study the status of these particles in terms of heavy metal pollution and their pollution status.
Results: 48 samples in contaminated conditions and 48 samples in non-contaminated conditions were collected at the specific points and exact times using a High Volume sampling pump with a flow rate of 110 L/min for 6 hours. Metal concentrations were measured using ICP. Except for Ni, Mn and Mg, the mean concentration of other studied metals were higher at dusty conditions as compared with their values in non-dusty conditions (p < 0.05). In dusty and non-dusty air conditions the order of heavy metals based on their concentrations were obtained as following: Zn> Mg> Mn> Ni> Cr> Pb> Fe> Cu and Mg> Mn> Ni> Pb> Fe> Cr, respectively. This result shows that the origin of zinc and copper metals and the increase in chromium concentration in polluted air are due to the entering of dust and pollution transfer from the outside area into cities. The cities of Ahvaz, Dezful, Mahshahr and Abadan were highly enriched in terms of heavy metals pollution either in dusty or non-dusty conditions.
Conclusion: The findings of this study showed that despite low concentration of heavy metals in airborne dust particles in clear and dusty air, high health risks of metals such as zinc in cities of Khuzestan province, especially Mahshahr are probable. Further investigation showed that particles are generally derived from intra-city or provincial activities, which call for more attention due to the drought conditions that attributes to more dust formation.
Vahideh Barzeghar, Akbar Gholampour, Mohammad Sadegh Hassanvand,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: This study was conducted to investigate the long-term temporal trends and spatial variations of ambient PM10, PM2.5, O3, concentrations in Tabriz city during the years 2006-2017.
Materials and Methods: Real-time hourly concentrations of PM10, PM2.5, O3 measured at nine air quality monitoring stations (AQMSs) were obtained from the Tabriz Department of Environment (TDoE) during 2006-2017 and analyzed. Spatial and temporal variations of pollutants using the Mann-Kendall's test and Moran’s I index were analyzed.
Results: The results of this study showed that the annual trend of PM10, PM2.5 was decreasing but remained almost constant for O3 during the study period. During some of the studied days, PM10, PM2.5 levels were exceeded greater than the WHO AQG and National standard levels. Moreover, the highest monthly mean concentrations of PM10 in October (80.3 µg/m³), PM2.5 in January (42.9 µg/m³) and O3 in June (77.8 µg/m³) were observed. Comparison between the stations indicated that the Raste Kuche station was more polluted than other stations.
Conclusion: Effective control planning and implementation policies are essential to improve the air quality of the Tabriz environment. Hence, information provided in this research can be used as a key step for city managers, policymakers, and health officials to reduce the health impacts of air pollution.
Azadeh Tavakoli, Arezoo Tavakoli, Masoumeh Mohammadi,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Indoor air pollution in hospitals could be a serious health threat to the patients, medical staff, and visitors. In previous studies, the importance of paying attention to air quality during the Coronavirus pandemic has been proven. In this study, the effect of visiters' presence under normal conditions and the imposition of hospital restrictions at the time of pandemic on air quality and environmental parameters in a hospital has been evaluated.
Materials and Methods: Air sampling was carried out in Valiasr Hospital of Zanjan in two periods, September 2019 (morning and visiting hours) and during the pandemic in October 2020. All wards inside and the outside of the hospital were examined for air pollutants (PM2.5, PM10, NO2, SO2, CO2) and environmental parameters (temperature, humidity, and sound levels).
Results: The results of this study showed that except for the sound levels, other pollutants are at an acceptable level. Particulate matter of different sizes in the air of the hospital has a correlation, often with an external source, and has been imported through construction activitie;. However, nitrogen dioxide concentration is dependent on urban traffic. Visiting hours are associated with an increase in the concentration of particulate matter and the sound levels. The pandemic had a positive effect in some wards, on some parameters and often improved the air quality due to the imposing strict health protocols.
Conclusion: This study showed that natural ventilation has a direct effect on the air quality inside of the hospital. It is also suggested that in wards where patients are sensitive or in the need of intensive care, restrictions on commuting and visitation be applied.
Arezoo Tavakoli, . Azadeh Tavakoli,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Bioaerosols as small particles enter the body by inhalation and lead to respiratory diseases based on type, concentration, and exposure time. In sensitive workplaces such as medical centers, it is necessary to pay attention to the type and population of these pollutants and the possibility of nosocomial infections. In the present study, the population and type of bioaerosols (bacteria and fungi) in the air of different hospital wards under normal conditions, visiting hours, and Covid-19 pandemic was evaluated.
Materials and Methods: Air sampling was carried out in different wards and ambient air of Valiasr Hospital of Zanjan during September 2019 (morning and visiting hours) and October 2020 (Corona pandemic) using an air sampling pump (Flite 3- SKC Ltd) with a flow of 14.1 L/min and then cultured in Sabaroud dextrose agar and nutrient agar.
Results: The results showed that air pollution in wards such as infectious diseases and clinics in both periods was more than other wards. The microbial density during visiting hours (before the coronavirus outbreak) was almost 30% higher than normal conditions. In October 2020, due to the coronavirus outbreak and reduced traffic, microbial air pollution in the hospital decreased. In both periods of study, the frequency of gram-positive bacteria, especially Staphylococcus species (49%) was higher than other bacteria and among fungal species the frequency of Aspergillus (47%) was higher than others.
Conclusion: This study showed that traffic restrictions caused by the coronavirus pandemic reduce microbial density in hospital space and this achievement can be used in the future with the aim of improving air quality and controlling nosocomial infections.
Tahereh Ebrahimi, Khosro Piri, Asghar Abdoli, Masoud Tohidfar,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: The presence of toxic compounds, including phenol, due to industrial development, poses a threat to the environment. Utilizing hairy roots has emerged as a potential method to remove these toxins. This review aims to explore the efficacy of hairy roots in absorbing phenol pollutants and the influencing parameters.
Materials and Methods: This study was conducted using a descriptive-review method based on existing literature gathered from databases such as Science Direct, PubMed, and Google Scholar. The focus of the study was on the purification of phenol using hairy roots. Keywords such as Phytoremediation, Hairy root, Phenol, and Transgenic roots were used for data collection.
Results: Results show successful phenol removal by hairy roots, potentially attributed to abundant production of peroxidase enzymes. Various factors, such as hydrogen peroxide (H2O2), incubation time, pH, plant species, and pollutant concentration, impact phenol removal efficiency. Notably, plants like Brassica napus, rich in peroxidase enzymes, exhibit high efficiency in removing phenol pollution up to 500 mg/L, with H2O2 and within a pH range of 4-9.
Conclusion: In conclusion, hair roots possess significant adsorption capacity for phenol. However, phenol concentration, contact time, pH, and temperature influence their performance. Therefore, further research is required to explore optimal conditions for phenol removal.
Javad Torkaman, Mehrdad Ghodskhah Daryaei, Shahrooz Sahranavard,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Climate change and environmental pollutants affect the growth of plant species. These effects can be recognized in the tree growth rings. This study aimed to investigate the effects of the precipitation and temperature in four decades (1975-2015) and air pollutants in the last decade on the average growth of pine trees (Pinus eldarica).
Materials and Methods: The studied area is Chitgar Forest Park located in the northwest of Tehran city and the studied species is the forest pine (Pinus eldarica). The research method is descriptive, the required climatic information was obtained from Mehrabad meteorological station and sampling was done by disc cutting from 10 forest pine trees. After preparing the samples, the number and width of annual rings were counted and measured using binoculars and a measuring table. One-way analysis of variance (ANOVA) was used at a significance level of 5% to investigate the significant difference in growth width in four decades.
Results: The results show that there is no significant difference between average precipitation in four decades, while average temperature and average growth have significant differences (p < 0.05). The amount of growth based on the growth index has decreased during four decades, and this decrease is more significant and obvious in the fourth decade due to the increase of pollutants such as ozone (O3) and nitrogen dioxide (NO2).
Conclusion: In general, the growth of forest pine trees has decreased during forty years with the increase of average annual temperature, which excessive decrease in the fourth decade is caused by pollutants such as ozone and nitrogen dioxide. It is suggested to do more research on sensitive species planted in urban areas to better understand the effect of pollutants on the growth and development of trees.
Alireza Zarasvandi, Maryam Delphi, Nadia Azizi, Fatima Rastmanesh, Gazelle Zarasvandi,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: During the last few decades, heavy metal pollution in indoor dust has been widely studied; While, the quality of the environment inside the cars has not been considered enough. Therefore, the specific objectives of this study generally include investigating the levels of selected heavy metals in the dust of private cars collected from Ahvaz city, as well as evaluating the health risk of carcinogenesis and exposure to the dust inside these cars through ingestion, inhalation, and skin absorption.
Materials and Methods: 10 cars were selected for this study. The condition of choosing the cars was not to wash the car for a week. Then, samples were collected and coded from the dust of the air conditioner filter and the cabin of each car. To determine the composition of heavy metals, spectroscopic analysis (ICP) was performed on the samples.
Results: The study of non-carcinogenic risk index (HI) in the present study indicates that the values of more than 1 and the health risk is high. The sequence of HI index values for heavy metals was obtained as Pb>Cu>Cr> Fe> Zn> Cd> Ni. Evaluated risks from different pathways in children was HQing < HQinhder while in adults follows HQingder< HQinh process. Additionally, the values of enrichment factor of the studied samples showed the maximum and minimum values for Cu (4.3) and Ni (8.3), the maximum and minimum geoaccumulation index for Fe (12.75) and Ni (1.9) and the amount of integrated pollution and pollution index were estimated to be 1.34+E27 and 2.07+E9, respectively, indicating the average range for the studied heavy metals.
Conclusion: According to this study, the risk of non-carcinogenic risk of heavy metals (except Fe and Cu) for children is estimated to be higher than that of adults. Furthermore, the investigation of the CR index for the three carcinogenic heavy metals (cadmium, chromium, and arsenic) has exceeded the safe level, which indicates ingestion and inhale as the target pathways for the worst adverse effects of heavy metals in children andadults, respectively. In the present study, the amount of heavy metals studied is more than the set standards. The results of the current study showedthe more enrichment of heavy metals in the car filter as compared with the cabin.
Zahra Khodarahmi, Sakine Shekoohiyan, Mohsen Heidari,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: Given the concern about the presence of microplastics in the air and settled dust, and the lack of a standard approach for their detection, it is necessary to investigate the methods and techniques used to study this type of pollution in Iran. Therefore, this study aimed to systematically review the methods and techniques used for sampling, quantification, and characterization of microplastics in the air and settled dust in indoor and outdoor environments in Iran.
Materials and Methods: In this systematic review, the keywords Microplastic*, Air*, Atmosphere*, Dust, Indoor, Outdoor, Iran, and their corresponding Persian equivalents were searched until Dec 1, 2023, in Scopus, PubMed, Web of Science, Google Scholar, Magiran, and SID databases. Obtained articles from the databases were analyzed in order to find the eligible ones.
Results: Overall, 175 articles were found in the initial search, and after removing the duplicates and nonrelevant, 13 eligible articles were included in the study. In most of the studies, the samples were digested with H2O2, and the microplastics were mainly analyzed using a variety of microscopes and µRaman spectroscopy. The abundance of microplastics in the indoor environment was much higher than in the outdoor environment.
Conclusion: The results of this study showed that there is the required equipment for the sampling and analysis of microplastics in air and settled dust in Iran, and these pollutants have been detected in both indoor and outdoor environments.
Adel Sheykhan, Gholamreza Moussavi, Mohsen Heidari,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The air quality index (AQI) does not account the interaction of multiple pollutants, meaning the high concentration and health risk of one pollutant may amplify the effects of others. The main aim of this study was to characterize the ambient air quality of Arak by assessing the combined effects and health risks associated with criteria air pollutants.
Materials and Methods: This study evaluated the ambient air quality of Arak for the year 1401 on the Persian Calendar, using the concentrations of criteria air pollutants averaged over appropriate timeframes. Additionally, the AQI, aggregate air quality index (AAQI), and health risk-based air quality index (HAQI) were calculated.
Results: Findings showed that the 1-hour concentrations of NO2, SO2, PM10, and PM2.5 exceeded national standards in 0.05%, 0.2%, 12.1%, and 35.5% of hours, respectively. The AQI, AAQI and HAQI values were above 100 in 54.4%, 77.3%, and 56.2% of hours, respectively. PM2.5 was the major pollutant in over 99% of cases.
Conclusion: The results indicated that AAQI and HAQI, in comparison to AQI, characterized the air quality as more polluted. This stricter assessment by AAQI and HAQI may encourage more precautionary measures by authorities and the public. Thus, it is recommended that the decision-makers in Iran’s air quality monitoring in consider adopting these indices.
