Risk assessment of noise pollution by analyzing the level of sound loudness resulting from central traffic in Shiraz

Background: Today, the effects of environmental pollution on human life and human needs, which reduces the level of community health caused by traffic noise in large cities, are clearly visible by creating irritation and pathogenic conditions. The aim of this study was to assess the risk of noise pollution resulted from central traffic in Shiraz by analyzing its indicators and related components. Methods: By specifying the high traffic jam in Shiraz, the sound and its frequency in 156 points of the city were analyzed using a sound analyzer (Tes-1358C model). The sound pressure levels (LA and LP) and the one and one-third octave band were continuously measured in A and C networks. Then, data were extracted and analyzed using Excel 2016 and Minitab 18.1. Eventually, phon and sone indexes were calculated for the heavy traffic jam in some of the central streets of Shiraz and the results were statistically calculated and their charts were prepared with comfort disturbance ranges. Results: The highest harmful frequency of traffic in Shiraz was 50 Hz and 83.3 dB. The sound pressure level ranged from 70 to 92.7 dB in network A and 87.8 dB in network C. The maximum sound level was 87 phon and the maximum sone was 26 at 14 stations. Conclusion: According to the results, the sound pressure levels exceeded the environmental standards of Iran and the values of phon and sone were higher than the standard of comfort at night and day. Keywords: Noise pollution, Environmental pollution, Loudness perception, Health risk assessment, Shiraz

On the reliability of CALPUFF and AUSTAL 2000 modeling systems regarding smoke and vapor plume mergence

Observations at power plants have shown that smoke plumes from stacks frequently merge with vapor plumes from cooling towers. Wind speed and direction play a key role in merging vapor and smoke plume. Mergence of stack and cooling tower plume leads to formation of undesirable substances such as sulfuric acid aerosols, acid mist, and acid fly ash. The present study shows that smoke and vapor plume mergence is a common phenomenon in Mátra power plant in Hungary; however more studies must be conducted in the future to reveal the type and number of plume mergence in the mentioned plant. The present work also indicates that the CALPUFF and AUSTAL 2000 modeling systems cannot provide enough information with regard to vapor and smoke plume mergence

The relationship of air pollution and surrogate markers of endothelial dysfunction in a population-based sample of children

<p>Abstract</p> <p>Background</p> <p>This study aimed to assess the relationship of air pollution and plasma surrogate markers of endothelial dysfunction in the pediatric age group.</p> <p>Methods</p> <p>This cross-sectional study was conducted in 2009-2010 among 125 participants aged 10-18 years. They were randomly selected from different areas of Isfahan city, the second large and air-polluted city in Iran. The association of air pollutants' levels with serum thrombomodulin (TM) and tissue factor (TF) was determined after adjustment for age, gender, anthropometric measures, dietary and physical activity habits.</p> <p>Results</p> <p>Data of 118 participants was complete and was analyzed. The mean age was 12.79 (2.35) years. The mean pollution standards index (PSI) value was at moderate level, the mean particular matter measuring up to 10 μm (PM₁₀) was more than twice the normal level. Multiple linear regression analysis showed that TF had significant relationship with all air pollutants except than carbon monoxide, and TM had significant inverse relationship with ozone. The odds ratio of elevated TF was significantly higher in the upper vs. the lowest quartiles of PM₁₀, ozone and PSI. The corresponding figures were in opposite direction for TM.</p> <p>Conclusions</p> <p>The relationship of air pollutants with endothelial dysfunction and pro-coagulant state can be an important factor in the development of atherosclerosis from early life. This finding should be confirmed in future longitudinal studies. Concerns about the harmful effects of air pollution on children's health should be considered a top priority for public health policy; it should be underscored in primordial and primary prevention of chronic diseases.</p

Assessment of Concentration and the Annual Effective Dose of Radon Gas in Imam Hospital Indoor Air

Introduction and purpose: Exposure to natural sources of radiation, especially&nbsp;radon and its short-term products, is an important issue around the world. Radon&nbsp;exposure causes lung cancer in humans. Therefore, the aim of this study was to&nbsp;measure the concentration of radon gas and its annual effective dose in Imam&nbsp;Hospital of Tehran, Iran and to compare its concentrations with the recommended&nbsp;standards.&nbsp;Methods: Radon levels and meteorological parameters (temperature, pressure,&nbsp;and moisture) were measured in different levels and in four seasons, using&nbsp;Radstar and Lutron Electronic devices, respectively, during June 2014-June&nbsp;2015. The collected data were analyzed through SPSS 18. Annual effective&nbsp;dose was calculated, using the equation for annual effective dose introduced by&nbsp;Scientific Committee of the United Nations.&nbsp;Results: The highest concentration of radon and annual effective dose were&nbsp;observed in the winter, which were 82/15 Bq/m3 and0/48 ms/y, respectively.&nbsp;Furthermore, concerning the various levels, the highest concentration was&nbsp;observed in the lowest level (56/1 Bq/m3).Conclusion: The results of the current study demonstrated that radon concentration&nbsp;was lower than the standards set by Environmental Protection Agency and World&nbsp;Health Organization. Regarding this, there are not concerns about the possible&nbsp;dangers of radon gas activities for the personnel and patients of the hospital.&nbsp

Triple-diffusive natural convection in a square porous cavity

The triple-diffusive flow, heat and mass transfer in a cavity filled with a porous medium and saturated with a mixture is theoretically studied in a cavity with differential temperature and concentrations at the side walls. The effect of buoyancy forces due to mass transfer of phases is also taken into account using the Boussinesq approximation. The governing equations are transformed into a non-dimensional form and numerically solved using the finite element method. Five groups of non-dimensional parameters including the Rayleigh number, the Lewis numbers for phases 1 and 2, and the buoyancy ratio parameters for phases 1 and 2 are obtained. The effect of each group of non-dimensional parameters on the heat and mass transfer in the cavity is discussed. The results show that for specific values of the Lewis number of one phase, the heat transfer of the mixture and the mass transfer of the other phase can be maximum. The presence of one phase could reduce or enhance the mass transfer of the second phase depending on the Lewis number of phases

Simulation of Concentrations and Dispersion of Hydrogen Sulfide (H2S) Due to Incinerators of Sulfur Recovery Units in a Gas Refinery in Asaluyeh

Background and Goal: Refineries are the main source of various pollutants, including Hydrogen Sulfide (H2S). Therefore distribution and control processing to meet the environmental standard limits is an important issue in industrial units.The present study was carried out to investigate H2S concentrations and dispersion patterns originating from incinerators of sulfur recovery units in a gas refinery located in Asaluyeh. Materials and Methods: In this study, H2S concentrations exhausted from two incinerators&rsquo; stacks and also ambient H2S concentrations at five monitoring stations in and around the refinery were measured in four seasons from summer 2014 to spring 2015. Moreover, the ambient concentrations and dispersion of H2S were simulated at average times of 1-hr and 8-hr on 50&times;50 km2 scale using &nbsp;AERMOD model and the simulated results were compared with the measured ones. Meanwhile, the concentration contour plots and the sensitive regions were determined using GIS. Results: The simulation results indicated that maximum ambient H2S concentrations were in 1-h average. Assessment of model performance was performed by comparison of H2S simulated and measured concentrations using statistical analysis and showed that the correlation coefficients in summer 2014, autumn 2014, winter 2014 and spring 2015 were 0.77, 0.89, 0.75 and 0.8, respectively. Conclusion: The results of this study showed that the variations of measured concentrations were consistent with those of simulated ones. Meanwhile, the contribution of neighbor industries was determined. Comparision of 8-h H2S concentrations with OSHA and NIOSH standard limits indicated that there was no significant health risk in this refinery

Triple-diffusive natural convection in a square porous cavity

The triple-diffusive flow, heat and mass transfer in a cavity filled with a porous medium and saturated with a mixture is theoretically studied in a cavity with differential temperature and concentrations at the side walls. The effect of buoyancy forces due to mass transfer of phases is also taken into account using the Boussinesq approximation. The governing equations are transformed into a non-dimensional form and numerically solved using the finite element method. Five groups of non-dimensional parameters including the Rayleigh number, the Lewis numbers for phases 1 and 2, and the buoyancy ratio parameters for phases 1 and 2 are obtained. The effect of each group of non-dimensional parameters on the heat and mass transfer in the cavity is discussed. The results show that for specific values of the Lewis number of one phase, the heat transfer of the mixture and the mass transfer of the other phase can be maximum. The presence of one phase could reduce or enhance the mass transfer of the second phase depending on the Lewis number of phases

Risk assessment of noise pollution by analyzing the level of sound loudness resulting from central traffic in Shiraz

Background: Today, the effects of environmental pollution on human life and human needs, which reduces the level of community health caused by traffic noise in large cities, are clearly visible by creating irritation and pathogenic conditions. The aim of this study was to assess the risk of noise pollution resulted from central traffic in Shiraz by analyzing its indicators and related components. Methods: By specifying the high traffic jam in Shiraz, the sound and its frequency in 156 points of the city were analyzed using a sound analyzer (Tes-1358C model). The sound pressure levels (LA and LP) and the one and one-third octave band were continuously measured in A and C networks. Then, data were extracted and analyzed using Excel 2016 and Minitab 18.1. Eventually, phon and sone indexes were calculated for the heavy traffic jam in some of the central streets of Shiraz and the results were statistically calculated and their charts were prepared with comfort disturbance ranges. Results: The highest harmful frequency of traffic in Shiraz was 50 Hz and 83.3 dB. The sound pressure level ranged from 70 to 92.7 dB in network A and 87.8 dB in network C. The maximum sound level was 87 phon and the maximum sone was 26 at 14 stations. Conclusion: According to the results, the sound pressure levels exceeded the environmental standards of Iran and the values of phon and sone were higher than the standard of comfort at night and day