Ramin Nabizadeh Nodehi, Ph.D.
Vol 1 No 4 (2016): Autumn 2016
Introduction: Air pollution in metropolitans is an important problem and health concern. Air pollution increases respiratory diseases, significantly. We evaluated the relation between COPD and criteria air pollutants in six major cities of Iran including Tehran, Mashhad, Tabriz, Isfahan, Shiraz and Arak by AirQ model, developed by World Health Organization.
Materials and methods: At first, hourly data of pollutants collected from the Department of Environment of cities and validated according to WHO guidelines. Quantification of the number of cases COPD were performed by using statistical analysis and the World Health Organization model.
Results: Results showed total cumulative numbers of hospital admission cases due to COPD (HA-COPD) estimated in the present study were 372, 102, 130, 96, 55 and 29 cases in Tehran, Mashhad, Isfahan, Shiraz, Tabriz and Arak, respectively. According to obtained results, among seven metropolises, the highest and lowest COPD rate dedicated to Tehran and Arak, respectively.
Conclusions: Air pollution is considered as a major threat to public health in major cities of Iran. This study proved association between short-term exposure to O3 and NO2 and hospital admission for respiratory diseases. Therefore, policy makers and authorities should use appropriate actions and attempts based on scientific evidence in order to reduce pollutants, control air pollution and diminish their harmful effects on health of residents.
Introduction: The vapor of some reagents and organic solvents are the major agents of indoor pollution in chemical laboratories. Therefore students and technicians who work in these polluted places are exposed to high concentrations of these kinds of VOCs. Chloroform, dichloromethane, carbon tetrachloride are applied in laboratories as chemical solvents. Since mentioned compounds have various side effects, personal exposure of these VOCs should be monitored.
Materials and methods: In this study, personal exposure to chlorinated organic solvents in breathing zone of chemical laboratory technicians and students were monitored by diffusive personal samplers. After exposure, the chemical substances collected on sorbing cartridges were desorbed and analyzed by GC/MS.
Results: The mean values of chloroform in breathing zone of all groups were significantly greater than two other organic solvents. Moreover carbon tetrachloride had the least concentration. The mean values for exposure of chlorinated organic solvents in breathing zone of occupationally exposed groups were significantly greater than the occupationally non-exposed groups but below the 2000 ACGIH TLV. Significant differences were indicated in three studied groups monitoring for chloroform and dichloromethane (Pvalue< 0.05).
Conclusions: From the results of this pilot study, it seems that indoor air in chemical laboratories of universities is in the acceptable condition. It should be noted that chronic exposure to these compounds in occupational environments is justified enough to monitor the VOCs continually.
Introduction: Gamma ray radiation can cause ionization and harmful effects on human health due to its high levels of energy. However, contrary to popular belief, natural sources of gamma radiation are far greater in number than artificial sources. This study aims to determine the environmental gamma dose rate and the zoning map of Tehran, and estimate the annual effective dose and the excess risk of cancer in Tehran.
Materials and methods: This study is descriptive and cross-sectional. In it, the researchers measured the gamma radiation rate using a Geiger Muller detector at 50 outdoor stations in Tehran during the winter and the spring of 2016. The data was zoned using Arc GIS 10.3.
Results: The average background environmental gamma dose rate in Tehran was obtained at 605.54 nsv/h. There is a statistically significant difference between radiation in winter and in spring (P <0.05). The annual effective dose for the inhabitants of Tehran and the cancer risk were estimated to be 0.74 mSv and 2.29×10-3 respectively.
Conclusions: The annual effective dose and cancer risk in the lifetime of a Tehran city resident due to background gamma radiation were higher than the global average. Epidemiologic studies are recommended to assess the likely prevalence of chronic diseases associated with natural radiation among the residents of Tehran.
Introduction: The vacuum UV (VUV) system is a novel chemical-less advanced oxidation processes (AOP) used to decompose different class of organic contaminants. The present study aimed at investigating the efficiency of VUV process to degrade toluene as a model of aromatic hydrocarbons from the gas stream in a bench-scale photo-reactor.
Materials and methods: The effect of various parameters including radiation flux, relative humidity, toluene concentration, and ozone dosage were investigated on toluene degradation in the VUV process.
Results: The results showed that increasing the relative humidity up to 45% could considerably accelerate the oxidation of toluene as compared with the dry air stream in the process. Complete destruction of toluene was reached at radiation fluxes of 0.366 and 0.732 mJ/cm2 for 5 and 15 ppm of toluene, respectively. Dosing ozone into the VUV photo-reactor at the dosages of 20, 40 and 60 μg/s led to improve the toluene degradation from 65.6% to 100%. The removal of toluene in the VUV process under the selected optimum conditions followed a pseudo-first order reaction model with the degradation rate values of 5.99 mg/L.min.
Conclusions: It was found that VUV process might be a novel and emerging AOP, which can efficiently perform for decomposition of aromatic hydrocarbons in contaminated air stream.
Introduction: Air pollution is a serious health concern worldwide, accounting for high premature morbidity and mortality annually. In this article, we explain the framework of a series of interrelated researches for studying particulate matter (PM10, PM <10 μm) health impacts from dust storm and non-dust storm conditions in Tehran, Iran.
Materials and methods: PM10 samples will be collected daily from two representative stations simultaneously during normal and dusty days by high volume samplers. PM chemical properties including ions, polycyclic aromatic hydrocarbons, metal (loid)s and oxidative potential will be analyzed. For in vitro biological toxicity, cytokine release from peripheral blood mononuclear cells and A549 cell line will be assayed. Also, DNA damage on A549 cell line will be examined using comet assay. In addition, DNA methylation of PBMCs and hemolysis of red blood cells (RBCs) will be accomplished. In a parallel panel study, after completing demographic and the International Study of Asthma and Allergies in Childhood (ISSAC) questionnaires, two groups of students will be selected. The exhaled breath condensate will be conducted to measure TNF-α, 8-IP, IL-6.
Conclusions: This study aimed to evaluate the components, oxidative potential and biological effects induced by PM. Our research will be provided information on the toxicity potential of PM related to dust storm and traffic to help policy makers to establish strategies and prioritize resource allocation in comprehensive plan for PM control.
Introduction: Expanding a spreadsheet model which is used for key engineering calculations for hazardous waste incinerations (HWI) is the most important task in the management of hazardous wastes. The objectives of this study were to develop rigorous calculation procedures for the design and analysis of the incinerator, and incorporate these procedures into an easy-to-use computer program.
Findings: In this study, an innovative spreadsheet model application for the HWI is presented in order to provide a convenient method for calculation of flue gas and incinerator design data based on the thermodynamic and the stoichiometric calculations.
Conclusions: HWI program was organized into three parts in MS Excel: input data, calculations, and output of the results. A conceptual dataset was used to show the performance of this model using different criteria parameters. The model proved to be an efficient tool to help to engineering calculations for HWI.