Ramin Nabizadeh Nodehi, Ph.D.
Vol 2 No 1 (2017): Winter 2017
Introduction: For many years, the historical city of Isfahan in the center of Iran has been faced with heavy transportation traffic. This heavy transportation is introducing large amounts of air pollutants into the city, causing many risks to human health, environment, etc. This study evaluates the fuel-based emission inventory of NOx, SOx, HCs and CO released into the atmosphere of Isfahan by both trains and airplanes. In addition, the emission inventory of PM10, PM2.5 and volatile organic compounds were investigated for Isfahan trains.
Materials and methods: The validated methods of the United States Environmental Protection Agency and the European Environmental Agency have been utilized to estimate the emission inventories of trains and airplanes in Isfahan metropolitan. Both methods are based on average emission factors.
Results: The results in 2016 show that, an average of 13,297 tons NOx, 0.13 tons SOx, 691 tons HC, 727 tons VOCs, 329 tons PM10, 319 tons PM2.5 and 1374 tons CO were released into the atmosphere of Isfahan metropolitan by trains every year. Investigations of the airplane emission inventory show that in 2016, an average of 8,076 tons CO2, 3.8 tons HC, 19.4 NOx, 22.8 tons CO and 2.54 tons SOx are released annually into the atmosphere by airplanes in Isfahan metropolitan.
Conclusions: It is concluded that the most important pollutants emitted from railroad systems in Isfahan are nitrogen oxides. Sepahan-Shar suburb, in the southern part of Isfahan, receives the majority of generated pollutants by passing trains. At the present time aircraft are not an effective sources of pollutants in Isfahan.
Introduction: Long-term exposure to particulate matter with an aerodynamic diameter less than 2.5 μm is associated with lung cancer incidence. This study aimed to estimate the number of lung cancer deaths attributed to lung-term exposure to PM2.5 among people older than 30 years in 15 cities of Iran during 2015- 2016 using AirQ+ modelling approach.
Materials and methods: Validation of monitoring stations was done according to WHO’s criteria for health impact assessment of air pollution. As AirQ+ needs, 24-h concentrations of PM2.5 during a year, total population and at-risk population, baseline incidence of lung cancer, and cut-off value of 10 μg/m3 for PM2.5 concentration were prepared and entered into the model.
Results: Annual concentrations of particulate matter in all cities were 1.8 to 6.7 times higher than WHO’s guideline. The most and least cases of lung cancer deaths due to PM2.5 were estimated to be in Karaj and Birjand, respectively. Total mortality of lung cancer attributed to PM2.5 in these 15 cities were 120 cases.
Conclusions: Since air pollution’s health impacts impose financial losses to countries, results of this study can be useful for decision-makers to highlight areas requiring urgent action.
Introduction: Air pollution can cause health problems on a global scale. Air quality predicting is an effective method to protect public health through early notification hazards of air pollution. The aim of this study is forecasting next day air quality index (AQI) in Tehran, Iran.
Materials and methods: Various approaches such as multiple linear regression (MLR) analysis, decision trees (DT), and multi-layer perceptron artificial neural networks (ANN), feature selection with regression analysis before artificial neural networks (MLR-ANN) and feature selection with decision trees before artificial neural networks (DT-ANN) were used for forecasting next day AQI based on meteorological data and one and two days ago AQI. Root mean square error (RMSE) and correlation coefficient (CC) are used to assess models accuracy.
Results: The results showed that forecasting of next day AQI by DT-ANN model is more accurate than others. Statistics indexes of this model such as RMSE and CC have been determined as 21.26 and 0.66 respectively. Using of DT for features selection because of reducing the number of inputs and decrease the model complexity was considered better than using the initial data.
Conclusions: The applications of air quality forecasting methods could be applied for air quality management purposes and protect public health.
Introduction: Waste sources include municipal solid waste and municipal wastewater, as well as the air pollutants produced by human and animal digestion. The purpose of the present study was to investigate the level of air pollutants resulting from these waste sources.
Materials and methods: In order to conduct this study, emission factors defined by the European Environment Agency were used. First, the type and quantity of the municipal solid waste produced in Isfahan were studied. Next, the amount of municipal solid waste recycling and compost were determined. Then, using related emission factors, emission inventories of PM2.5 and PM10 from municipal solid waste landfill, and ammonia from composting processes were determined. In the subsequent step, the volume from the municipal wastewater treatment facilities of Isfahan and selected nearby cities was specified, and by using the emission coefficient, the total emission of VOCs was determined. By specifying city population and predicting the population for the next 10 years, ammonia from human digestion was estimated.
Results: The results showed that annually, 20391 g of VOCs are produced by municipal wastewater treatment facilities in the Isfahan metropolitan area. In addition, it was specified that 675980 kg PM10 and 319740 kg PM2.5 were emitted into the air from Isfahan’s Gardane Zinal landfill each year. Annual amounts of carbon monoxide and ammonia produced by composting are estimated at 11191 and 13189 tons, respectively.
Conclusions: Investigating the contributions of various sources of pollutants in metropolitan Isfahan may lead to a suitable context in which the share of different sources of pollutants is understood, and therefore, air pollution management will be possible.
Introduction: One of the important issues faced by most hospitals is an increase in nosocomial infection caused by exposure to airborne bioaerosols such as fungi and bacteria. It may be more dangerous for people who impaired immune systems. The aim of this study was to evaluate fungal contamination of indoor air of different wards of general hospitals of Lorestan, Iran.
Materials and methods: In order to assess microbial air sampling ZEFON Pump, equipped with single-stage cascade BioStage impactor was used. The mobile culture medium used for assessing fungal samples was Sabouraud Dextrose Agar (SDA) with chloramphenicol. Samples transferred to the laboratory and analyzed. Temperature and humidity were measured in different sampling areas.
Results: The highest level of fungal air contamination in different wards of hospitals No. 1, 2, and 3 were respectively in the surgical ICU (178.53 ± 207/20 CFU/m³), operating room (160.11 ± 99.62 CFU/m3), and CS ICU (162.72 ± 110.58 CFU/m³), and the lowest concentration levels were observed in ICU General (94.84 ± 65.89 CFU/m³), NICU (101.35 ± 112.64 CFU/m³) and operating room (70.67 ± 43.27 CFU/m³). The most common fungal agents detected include Cladosporium, Penicillium, Aspergillus, Chrysosporim, Alternaria, Fusarium, Rhizopus, Trichosporn Asahii, Cryptococcus albidus, Rhodotorula glutenis. Also, Aspergillus fumigatus was identified in most hospital wards.
Conclusions: High level of fungal contamination in certain wards of Khorramabad educational hospitals was indicated and an effective control system to reduce the fungi concentration is needed. Moreover, methods such as HEPA filters and UV lamps can use to reduce airborne fungi.
Air pollution can adversely affect human health, vegetation growth, buildings and monuments throughout the world, especially in developing countries. There is an increasing concern about the various air pollutants including particulate matter (PM), volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) in ambient air of Iran. VOCs and PAHs are important types of air pollutants which are generated from human activities (e.g. transportation and industrial activities) in cites with high population density, whereas PM is formed from a variety of natural and anthropogenic sources. Iran, like most other countries in the Middle East, is affected annually by multiple dust storms. In general, the level of ambient PM originated from natural sources in some of Iranian cities such as Ahvaz and Zabol has been reported as the highest value throughout the world. When PM are associated with pollutants such as VOCs and PAHs in the lower atmosphere lead to the buildup of multiple pollutants and have the longest atmospheric lifetime and more readily penetrate into the lungs and consequently increase the mortality rate. Therefore, reliable source identification and apportionment of air pollutants is necessary and can be a useful tool for management and implementation of associated control strategies. This review has been focused on the source identification and apportionment of PM, VOCs and PAHs in some cities of Iran.