Iranian Journal of

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 (PM_2.5) 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 PM_2.5 in Tehran and its distribution for 2017 and 2018 was calculated. Hourly PM_2.5 from monitoring stations used to estimate the mean PM_2.5 for 349 Tehran neighborhoods.
Results: The results showed that the average population weighted PM_2.5 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 PM_2.5 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 PM_2.5 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.

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.

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.

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 PM_2.5 (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.

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 (PM_2.5) 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 PM_2.5 in Zahedan during this study was 36.86 µg/m³. The maximum and minimum PM_2.5 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 PM_2.5 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.

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.

Background and Objective: This study was conducted to investigate the long-term temporal trends and spatial variations of ambient PM₁₀, PM_2.5, O₃, concentrations in Tabriz city during the years 2006-2017.
Materials and Methods: Real-time hourly concentrations of PM₁₀, PM_2.5, 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, PM_2.5 was decreasing but remained almost constant for O₃ during the study period. During some of the studied days, PM₁₀, PM_2.5 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), PM_2.5 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.

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 (PM_2.5, 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.

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.
 

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 PM_2.5 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. PM_2.5 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.