Title: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016: A systematic analysis for the Global Burden of Disease Study 2016

Author(s): Mohammad Sadegh Hassanvand, et all

لینک مشاهده مقاله کامل

Abstract: The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of risk factor exposure and attributable burden of disease. By providing estimates over a long time series, this study can monitor risk exposure trends critical to health surveillance and inform policy debates on the importance of addressing risks in context.

Title: Short-term effects of particle size fractions on circulating biomarkers of inflammation in a panel of elderly subjects and healthy young adults

Author(s): Mohammad Sadegh Hassanvand, Kazem Naddafi, Homa Kashani, Sasan Faridi, Nino Kunzli, Ramin Nabizadeh, Fatemeh Momeniha, Akbar Gholampour, Mohammad Arhami, Ahad Zare, Zahra Pourpak, Mohammad Hoseini, Masud Yunesian

 لینک مشاهده مقاله کامل

Abstract: weeks and included white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF). We measured hourly indoor and outdoor exposure to PM10, PM2.5-10, PM2.5, PM1-2.5, and PM1 mass concentration to derive weighted averages of personal exposure based on simultaneously collected time-activity data. The random intercept linear mixed effects model was used for data analysis.
We observed significant positive associations for WBC and IL-6 with exposure to PM10, PM2.5-10, PM2.5, PM1-2.5, and PM1; sTNF-RII with PM2.5, PM1-2.5, and PM1; hsCRP with PM2.5 and PM1; and vWF with PM10 and PM2.5-10, PM2.5, and PM1-2.5 mass concentration in elderly subjects from the current-day and multiday averages. For healthy young adults, we found significant positive associations for WBC and IL-6 with exposure to PM10, PM2.5-10, PM2.5, and PM1-2.5, but no with PM1. The results showed that increase of hsCRP, sTNF-RII, and vWF were not significantly associated with any of the PM sizes investigated in the healthy young subjects.
Our results provided some evidence that short-term exposure to PM10, PM2.5-10, PM2.5, PM1-2.5, and PM1 was associated with inflammation and coagulation blood markers, but associations were depended on PM size and also differed across the various time lag.

Title: Biodegradation of n-hexane as single pollutant and in a mixture with BTEX in a scoria/compost-based biofilter

Author(s): Mohammad Mehdi Amin, Amir Rahimi, Bijan Bina, Heshmatollah Nourmoradi, Mohammad Sadegh Hassanvand, Fazel Mohammadi-Moghadam, Samira Norouzi, MohsenHeidar

لینک مشاهده مقاله کامل

Abstract: This study evaluated the biodegradation of n-hexane as single pollutant, and in a mixture with benzene, toluene, ethylbenzene, and xylenes (BTEX) in a scoria/compost-based biofilter. Initially, the biofilter was fed with n-hexane and maximum elimination capacities (ECmax) of 10.7 and 8.1 g m−3 h−1 were obtained for inlet loading rates (ILR) of 14.0 and 11.6 g m−3 h−1 at empty bed retention times (EBRT) of 138 and 108 s, respectively. Michaelis–Menten kinetic model was well fitted to the experimental EC of n-hexane in the single pollutant condition. In the presence of BTEX, the removal efficiency of n-hexane dramatically decreased from 76 to 21% at EBRT of 108 s. In this condition, BTEX was easily degraded with an ECmax of 110.6 g m−3 h−1 for ILR of 119.1 g m−3 h−1. A competitive inhibition kinetic well described the n-hexane removal in the presence of BTEX with an inhibition constant of 0.151 g m−3. Moreover, the interaction index of benzene with the addition of BTEX was −0.702, indicating the significant inhibitory effect of BTEX on n-hexane biodegradation. This study revealed that, in the biofiltration of n-hexane/BTEX mixture, a significant decrease in BTEX concentration is a prerequisite for the efficient removal of n-hexane.

Title:  Bioaerosol exposure and circulating biomarkers in a panel of elderly subjects and healthy young adults

Author(s): Sasan Faridi, Kazem Naddafi, Homa Kashani, Ramin Nabizadeh, Mahmood Alimohammadi, Fatemeh Momeniha, Sholeh Faridi, Sadegh Niazi, Ahad Zare, Akbar Gholampour,  Mohammad Hoseini, Zahra Pourpak, Mohammad Sadegh Hassanvand, Masud Yunesian

لینک مشاهده مقاله کامل

Abstract: Numerous studies have found that risk of cardiovascular diseases is associated with increased blood levels of circulating markers of systemic inflammation. We investigated associations of acute exposure to bioaerosols (bacteria and fungi) with blood markers of inflammation and coagulation using panels of elderly subjects and healthy young adults. We conducted a panel study of 44 nonsmoker elderly subjects in a retirement communities and a panel study of 40 healthy young adults living in a school dormitory within Tehran city, Iran. Blood sample biomarkers were measured weekly over 6 weeks and including high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), von Willebrand factor (vWF), white blood cells (WBC) count and interleukin-6 (IL-6). We found significant positive associations for IL-6 and WBC with exposure to Aspergillus spp. (As), Cladosporium spp. (Cl), Penicillium spp. (Pe), total fungi (TF) and Micrococcus spp. (MI); vWF with Cl and MI; sTNF-RII with Staphylococcus spp. (ST) in healthy young adults from the current-day and multiday averages. For elderly subjects, we observed significant positive associations for hsCRP, sTNF-RII and WBC with exposure to MI, but not with ST and total bacteria (TB). Our results showed the strongest significant positive associations for IL-6 with MI, ST and TB in elderly people. In addition, IL-6 was also positively associated with As, Cl and Pe in elderly. Also, the results showed that increase of vWF was significantly associated with bacterial and fungal aerosols, except Bacillus spp. (BA) at some lags in elderly subjects. Pooled results support the pivotal role of bioaerosols in increasing the level of some of inflammatory biomarkers, especially IL-6 and WBC in healthy young adults but possibly also in elderly people.

Title:  Elemental composition of particulate matters around Urmia Lake, Iran

Author(s): Akbar Gholampour, Ramin Nabizadeh, Mohammad Sadegh Hassanvand, Shahrokh Nazmara, Amir Hossein Mahvi

لینک مشاهده مقاله کامل

Abstract: Atmospheric particulate matters and their elements were concurrently measured at two sites located in the north and southeast parts of Urmia Lake from January to September 2013. At both sampling sites, average concentrations of total suspended particulate, particles with the aerodynamic diameter of smaller than 10 µm, smaller than 2.5 µm, and smaller than 1 µm were 260 ± 106, 180 ± 73, 30 ± 8, and 25 ± 7 µg m−3, respectively. The analyzed water soluble ions accounted for approximately 11%–13% mass concentrations of total suspended particulate and 8%–9% of particles smaller than 10 µm, and the sum of the concentrations of the analyzed elements associated with both ranged from 9 to 41 µg m−3 (6.5%–9.6% in mass) and 7 to 26 µg m−3 (5.5%–11.3% in mass), respectively. Thus, particulate matter was composed of a complex mixture of minerals such as halite, quartz, gypsum, hexahydrite, and Bassanite.

Title: Estimating national dioxins and furans emissions, major sources, intake doses, and temporal trends in Iran from 1990-2010

Author(s): Fatemeh Momeniha, Sasan Faridi, Heresh Amini, Mansour Shamsipour, Kazem Naddafi, Masud Yunesian, Sadegh Niazi, Kimiya Gohari, Farshad Farzadfar, Ramin Nabizadeh, Adel Mokammel, Amir Hossein Mahvi, Alireza Mesdaghinia, Homa Kashani, Simin Nasseri, Akbar Gholampour, Reza Saeedi and Mohammad Sadegh Hassanvand

لینک مشاهده مقاله کامل

Abstract: Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) are highly toxic persistent organic pollutants (POPs), which can cause various health outcomes, such as cancer. As a part of the National and Sub-national Burden of Disease Study (NASBOD), we aimed to estimate dioxins and furans national emissions, identify their main sources, estimate daily intake doses, and assess their trend from 1990–2010 in Iran

Title: Ambient temperature and cardiovascular mortality: A systematic review and meta-analysis

Author(s): Mohammad Taghi Moghadamnia, Ali Ardalan​​, Alireza Mesdaghinia, Abbas Keshtkar, Kazem Naddafi, Mir Saeed Yekaninejad

لینک مشاهده مقاله کامل

Abstract: Our study aims at identifying and quantifying the relationship between the cold and heat exposure and the risk of cardiovascular mortality through a systematic review and meta-analysis.
A systematic review and meta-analysis were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Peer-reviewed studies about the temperature and cardiovascular mortality were retrieved in the MEDLINE, Web of Science, and Scopus databases from January 2000 up to the end of 2015. The pooled effect sizes of short-term effect were calculated for the heat exposure and cold exposure separately. Also, we assessed the dose–response relationship of temperature-cardiovascular mortality by a change in units of latitudes, longitude, lag days and annual mean temperature by meta-regression.
fter screening the titles, abstracts and full texts, a total of 26 articles were included in the meta-analysis. The risk of cardiovascular mortality increased by 5% (RR, 1.055; 95% CI [1.050–1.060]) for the cold exposure and 1.3% (RR, 1.013; 95% CI [1.011–1.015]) for the heat exposure. The short-term effects of cold and heat exposure on the risk of cardiovascular mortality in males were 3.8% (RR, 1.038; 95% CI [1.034–1.043]) and 1.1%( RR, 1.011; 95% CI [1.009–1.013]) respectively. Moreover, the effects of cold and heat exposure on risk of cardiovascular mortality in females were 4.1% (RR, 1.041; 95% CI [1.037–1.045]) and 1.4% (RR, 1.014; 95% CI [1.011–1.017]) respectively. In the elderly, it was at an 8.1% increase and a 6% increase in the heat and cold exposure, respectively. The greatest risk of cardiovascular mortality in cold temperature was in the 14 lag days (RR, 1.09; 95% CI [1.07–1.010]) and in hot temperatures in the seven lag days (RR, 1.14; 95% CI [1.09–1.17]). The significant dose–response relationship of latitude and longitude in cold exposure with cardiovascular mortality was found. The results showed that the risk of cardiovascular mortality increased with each degree increased significantly in latitude and longitude in cold exposure (0.2%, 95% CI [0.006–0.035]) and (0.07%, 95% CI [0.0003–0.014]) respectively. The risk of cardiovascular mortality increased with each degree increase in latitude in heat exposure (0.07%, 95% CI [0.0008–0.124]).
Our findings indicate that the increase and decrease in ambient temperature had a relationship with the cardiovascular mortality. To prevent the temperature- related mortality, persons with cardiovascular disease and the elderly should be targeted. The review has been registered with PROSPERO (registration number CRD42016037673).

Title: Elemental and carbonaceous characterization of TSP and PM10during Middle Eastern dust (MED) storms in Ahvaz, Southwestern Iran

Author(s): Abbas Shahsavani, Maryam Yarahmadi, Mostafa Hadei, Mohammad Hossein Sowlat, Kazem Naddafi

لینک مشاهده مقاله کامل

Abstract: Middle Eastern dust (MED) storms carry large amounts of dust particles to the Southern and Western cities of Iran. This study aimed to characterize the elemental and carbonaceous composition of total suspended particles (TSP) and PM10 in Ahvaz, Iran. TSP and PM10 samples were collected using two separate high-volume air samplers. The sampling program was performed according to EPA guidelines and resulted in 72 samples. Twenty-eight elements and two carbonaceous components in TSP and PM10 were measured. Over the entire study period, the mean concentration (SD) of TSP and PM10 was 1548.72 μg/m3 (1965.11 μg/m3) and 1152.35 μg/m3 (1510.34 μg/m3), respectively. The order of concentrations of major species were Si > Al > Ca > OC > Na > B > Zn > Mn > K > Mg and Si > Ca > Al > Na > OC > B > K > Mn > Cu > Mg for TSP and PM10, respectively. Almost all elements (except for Cd, Cr, and Cu) and carbonaceous components (except for organic carbon) had dust days/non-dust days (DD/NDD) ratios higher than 1, implying that all components are somehow affected by dust storms. Crustal elements constituted the major portion of particles for both TSP and PM10 in both DDs and NDDs. The enrichment factor of elements such as Ca, Fe, K, Mg, Na, and Ti was near unity. Species such as Al, Ca, Fe, K, Na, Si, and EC had high correlation coefficients in both TSP and PM10 (except for EC). In conclusion, Ahvaz is exposed to high concentrations of TSP and PM10 during the MED period. Immediate actions must be planned to decrease the high concentrations of particulate matter in Ahvaz’s ambient air.

Title: Evaluation of formaldehyde concentration in the ambient air of a most populated Iranian city, Tehran

Author(s): Mohammad Hadi Dehghani, Mehdi Salari, Kazem Naddafi, Shahrokh Nazmara, Ehsan Ahmadi, Prashant Kumar

لینک مشاهده مقاله کامل

Abstract: Exposure to high levels of formaldehyde is known as both acute and chronic health problems, but the studies analyzing ambient concentrations of formaldehyde, especially in Middle East cities such as Tehran, are still rare. The aim of this study is to survey the variations in the concentration of formaldehyde in several areas with a high traffic volume of Tehran city during different seasons. The other objectives include understanding the influence of carbon monoxide, ozone and nitrogen dioxide concentrations, ambient temperature, relative humidity, and air pressure on the variation of formaldehyde concentration. Measurements were carried out during the period of 6 months between 2013 (December 22 to February 14) and 2014 (April 27 to June 20 at five different locations within the city, together with a background site. One hundred and eight samples, each averaged over 3 h from 11 a.m. to 2 p.m., were taken from the sampling locations. The average concentration of formaldehyde in the spring (22.7 ± 5.3 ppb) was found about 1.31 times higher than winter (17.3 ± 4.2 ppb). Formaldehyde concentrations demonstrated a significant correlation with the changes in air temperature (in the range of 0.46 to 0.66 for different locations) but not having any strong correlation with humidity and pressure. Carbon monoxide and nitrogen dioxide showed a significant coefficient of determination with formaldehyde concentrations with R 2 as 0.80 and 0.67 during the winter, respectively, whereas the corresponding R 2 values during spring were 0.39 and 0.41. Ozone showed a significant correlation with formaldehyde (R 2 = 0.64) during the spring and has not such the significant correlation during the season winter (R 2 = 0.23). Overall, it concluded that road vehicles were recognized as main contributor of formaldehyde production during both the seasons, especially in the winter, also, photochemical oxidation was another important and considerable contributor producing formaldehyde during the spring

Title: Radioactivity levels in the mostly local foodstuff consumed by residents of the high level natural radiation areas of Ramsar, Iran

Author(s): Nasrin Fathabadi, Ali AkbarSalehi, Kazem Naddafi, Mohammad Reza Kardan, MasudYunesian, Ramin NabizadehNodehi, Mohammad Reza Deevband, Molood Gooniban Shooshtari, Saeedeh Sadat Hosseini, Mahtab Karimi

لینک مشاهده مقاله کامل

Abstract: Among High Level Natural Radiation Areas (HLNRAs) all over the world, the northern coastal city of Ramsar has been considered enormously important. Many studies have measured environmental radioactivity in Ramsar, however, no survey has been undertaken to measure concentrations in the diets of residents. This study determined the 226Ra activity concentration in the daily diet of people of Ramsar. The samples were chosen from both normal and high level natural radiation areas and based on the daily consumption patterns of residents. About 150 different samples, which all are local and have the highest consumption, were collected during the four seasons. In these samples, after washing and drying and pretreatment, the radionuclide was determined by α-spectrometry. The mean radioactivity concentration of 226Ra ranged between 5 ± 1 mBq kg−1 wet weight (chino and meat) to 725 ± 480 mBq kg−1 for tea dry leaves. The 226Ra activity concentrations compared with the reference values of UNSCEAR appear to be higher in leafy vegetables, milk and meat product. Of the total daily dietary 226Ra exposure for adults in Ramsar, the largest percentage was from eggs. The residents consuming eggs from household chickens may receive an elevated dose in the diet.

Title: Dispersion modeling and health risk assessment of VOCs emissions from municipal solid waste transfer station in Tehran, Iran

Author(s): Maryam Sarkhosh, AliAkbar Shamsipour, Kamyar Yaghmaeian, Ramin Nabizadeh, Kazem Naddafi and Seyed Mohsen Mohseni

لینک مشاهده مقاله کامل

Abstract: The waste transfer stations (WTSs) is one of the most important factors affecting on environment and human health. This research is aimed to evaluate health risk of VOCs among WTS personnel and provide a model for dispersion of VOCs. The Air Pollution Model (TAPM) is able to simulate WTS emissions dispersion over each town.

Title: A systematic review of land use regression models for volatile organic compounds

Author(s): Heresh Amini, Masud Yunesian, Vahid Hosseini, Christian Schindler, Sarah B.Henderson, Nino Künzl

لینک مشاهده مقاله کامل

Abstract: Various aspects of land use regression (LUR) models for volatile organic compounds (VOCs) were systematically reviewed. Sixteen studies were identified published between 2002 and 2017. Of these, six were conducted in Canada, five in the USA, two in Spain, and one each in Germany, Italy, and Iran. They were developed for 14 different individual VOCs or groupings: benzene; toluene; ethylbenzene; m-xylene; p-xylene; (m/p)-xylene; o-xylene; total BTEX; 1,3-butadiene; formaldehyde; n-hexane; total hydro carbons; styrene; and acrolein. The models were based on measurements ranging from 22 sites in El Paso (USA) to 179 sites in Tehran (Iran). Only four studies in Rome (Italy), Sabadell (Spain), Tehran, and Windsor (Canada) met the Cocheos criterion of having at least one passive sampler per 3.4 km2 of study area. The range of R2 values across all models was from 0.26 for 1,3-butadiene in Dallas (USA) to 0.93 for benzene in El Paso. The average R2 values among two or more studies of the same VOCs were as follows: benzene (0.70); toluene (0.60); ethylbenzene (0.66); (m/p)-xylene (0.65); o-xylene (0.61); total BTEX (0.66); 1,3-butadiene (0.46); and formaldehyde (0.56). The common spatial predictors of studied VOC concentrations were dominated by traffic-related variables, but they also included proximity to ports in the USA, number of chimneys in Canada, altitude in Spain, northern latitudes in Italy, and proximity to sewage treatment plants and to gas filling stores in Iran. For the traffic-related variables, the review suggests that large buffers, up to 5,000 m, should be considered in large cities. Although most studies reported logical directions of association for predictors, some reported inconsistent results. Some studies included log-transformed predictors while others divided one variable by another. Only six studies provided the p-values of predictors. Future work may incorporate chemistry-transport models, satellite observations, meteorological variables, particularly temperature, consider specific sources of aromatic vs aliphatic compounds, or may develop hybrid models. Currently, only one national model has been developed for Canada, and there are no global LUR models for VOCs. Overall, studies from outside North America and Europe are critically needed to describe the wide range of exposures experienced by different populations.

Title: Land Use Regression Models for Alkylbenzenes in a Middle Eastern Megacity: Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR)

Author(s): Heresh Amini , Christian Schindler, Vahid Hosseini, Masud Yunesian, and Nino Künzli

لینک مشاهده مقاله کامل

Abstract: Land use regression (LUR) has not been applied thus far to ambient alkylbenzenes in highly polluted megacities. We advanced LUR models for benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX using measurement based estimates of annual means at 179 sites in Tehran megacity, Iran. Overall, 520 predictors were evaluated, such as The Weather Research and Forecasting Model meteorology predictions, emission inventory, and several new others. The final models with R2 values ranging from 0.64 for p-xylene to 0.70 for benzene were mainly driven by traffic-related variables but the proximity to sewage treatment plants was present in all models indicating a major local source of alkylbenzenes not used in any previous study. We further found that large buffers are needed to explain annual mean concentrations of alkylbenzenes in complex situations of a megacity. About 83% of Tehran’s surface had benzene concentrations above air quality standard of 5 μg/m3 set by European Union and Iranian Government. Toluene was the predominant alkylbenzene, and the most polluted area was the city center. Our analyses on differences between wealthier and poorer areas also showed somewhat higher concentrations for the latter. This is the largest LUR study to predict all BTEX species in a megacity.

Title: Reply to urbanization theory for growing trend of multiple sclerosis letter

Author(s): Dehghani, R., Sahraian, M.A., Yunesian, M., Hadeii, M., Gilasi, H.R., Kazemi-Moghaddam, V

لینک مشاهده مقاله کامل

Abstract: No abstract available

Title: Weighting Criteria and Prioritizing of Heat stress indices in surface mining using a Delphi Technique and Fuzzy AHP-TOPSIS Method

Author(s): Mehdi Asghari, Parvin Nassiri, Mohammad Reza Monazzam, Farideh Golbabaei, Hossein Arabalibeik, Aliakbar Shamsipour and Armin Allahverdy

لینک مشاهده مقاله کامل

Abstract: Heat stress as a physical harmful agent can increase the risk of health and safety problems in different workplaces such as mining. Although there are different indices to assess the heat stress imposed on workers, choosing the best index for a specific workplace is so important. Since various criteria affect an index applicability, extracting the most effective ones and determining their weights help to prioritize the existing indices and select the optimal index.In order to achieve this aim, present study compared some heat stress indices using effective methods. The viewpoints of occupational health experts and the qualitative Delphi methods were used to extract the most important criteria. Then, the weights of 11 selected criteria were determined by Fuzzy Analytic Hierarchy Process. Finally, fuzzy TOPSIS technique was applied for choosing the most suitable heat stress index.According to result, simplicity, reliability, being low cost, and comprehensiveness were the most determinative criteria for a heat stress index. Based on these criteria and their weights, the existing indices were prioritized. Eventually, wet bulb glob temperature appropriated the first priority and it was proposed as an applicable index for evaluating the heat stress at outdoor hot environments such as surface mines.The use of these strong methods allows introducing the most simple, precise, and applicable tool for evaluation the heat stress in hot environments. It seems that WBGT acts as an appropriate index for assessing the heat stress in mining activities at outdoors.

Title: Evaluation of the effects of various sound pressure levels on the level of serum aldosterone concentration in rats

Author(s): Parvin Nassiri, Sajad Zare, Mohammad R Monazzam, Akram Pourbakht, Kamal Azam, Taghi Golmohammadi

لینک مشاهده مقاله کامل

Abstract: Noise exposure may have anatomical, nonauditory, and auditory influences. Considering nonauditory impacts, noise exposure can cause alterations in the automatic nervous system, including increased pulse rates, heightened blood pressure, and abnormal secretion of hormones. The present study aimed at examining the effect of various sound pressure levels (SPLs) on the serum aldosterone level among rats. Materials and Methods: A total of 45 adult male rats with an age range of 3 to 4 months and a weight of 200 ± 50 g were randomly divided into 15 groups of three. Three groups were considered as the control groups and the rest (i.e., 12 groups) as the case groups. Rats of the case groups were exposed to SPLs of 85, 95, and 105 dBA. White noise was used as the noise to which the rats were exposed. To measure the level of rats’ serum aldosterone, 3 mL of each rat’s sample blood was directly taken from the heart of anesthetized animals by using syringes. The taken blood samples were put in labeled test tubes that contained anticoagulant Ethylenediaminetetraacetic acid. In the laboratory, the level of aldosterone was assessed through Enzyme-linked immunosorbent assay protocol. The collected data were analyzed by the use of Statistical Package for Social Sciences (SPSS) version 18. Results: The results revealed that there was no significant change in the level of rats’ serum aldosterone as a result of exposure to SPLs of 65, 85, and 95 dBA. However, the level of serum aldosterone experienced a remarkable increase after exposure to the SPL of 105 dBA (P < 0.001). Thus, the SPL had a significant impact on the serum aldosterone level (P < 0.001). In contrast, the exposure time and the level of potassium in the used water did not have any measurable influence on the level of serum aldosterone (P = 0.25 and 0.39). Conclusion: The findings of this study demonstrated that serum aldosterone can be used as a biomarker in the face of sound exposure.

Title: Application of universal thermal climate index (UTCI) for assessment of occupational heat stress in open-pit mines


لینک مشاهده مقاله کامل

Abstract: The purpose of this article is to examine the applicability of Universal Thermal Climate Index (UTCI) index as an innovative index for evaluating of occupational heat stress in outdoor environments. 175 workers of 12 open-pit mines in Tehran, Iran were selected for this research study. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, relative humidity and air flow rate were measured; then UTCI, wet-bulb globe temperature (WBGT) and heat stress index (HSI) indices were calculated. Simultaneously, physiological parameters including heart rate, oral temperature, tympanic temperature and skin temperature of workers were measured. UTCI and WBGT are positively significantly correlated with all environmental parameters (p<0.03), except for air velocity (r<-0.39; p>0.05). Moreover, a strong significant relationship was found between UTCI and WBGT (r=0.95; p<0.001). The significant positive correlations exist between physiological parameters including oral temperature, tympanic and skin temperatures and heart rate and both the UTCI and WBGT indices (p<0.029). The highest correlation coefficient has been found between the UTCI and physiological parameters. Due to the low humidity and air velocity (~<1 m/s) in understudied mines, UTCI index appears to be appropriate to assess the occupational heat stress in these outdoor workplaces

Title: Comparative Analysis of AHP-TOPSIS and Fuzzy AHP Models in Selecting Appropriate Nanocomposites for Environmental Noise Barrier Applications

Author(s): Mahdiyeh Naderzadeh, Hossein Arabalibeik, Mohammad Reza Monazzam, Ismaeil Ghasem

لینک مشاهده مقاله کامل

Abstract: Choosing the right material in the design of environmental noise barriers has always been a challenging issue in acoustics. In less-developed countries, the material selection is affected by many factors from various aspects, which makes the decision-making very complicated. This study attempts to compare and assign weights to the most important indices affecting the choice of appropriate noise barrier material. These criteria include absorption coefficient, transparency, tensile modulus, strength at yield, elongation at break, impact strength, flexural modulus, hardness, and cost. For this purpose, experts opinions was gathered through a total of 13 questionnaires and used for assigning weights by Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy process (FAHP) techniques. According to the AHP results, impact strength, with only a minor difference of 0.093 compared to the AHP, was recognized as the most important criterion. Finally, the optimal composite material was selected using two different methods; first by Technique for Order-Preference by Similarity to Ideal Solution (TOPSIS) based on the weights obtained from AHP, and next by directly applying the obtained weights from FAHP to the true measured values of parameters. As the results show, in both abovementioned methods, Polycarbonate-SiO2 0.3% with roughened surface (PCSI3-R) received the highest score and was selected as the preferred composite material. Given the close similarity of the results, to determine the superiority of one method over the other, some noise was added to the original data set from the mechanical and acoustic tests and then the variance of the changes in the final orders of preferences was calculated. This indicates the robustness of the method against the measurement errors and noise. The results shows that under the same circumstances, the overall order shift variance in the classic TOPSIS is six times higher than that of the fuzzy AHP method.

Title: An Investigation on Transparency and Mechano-Acoustic Properties of Poly Methyl Methacrylate/Polycarbonate Based Nanocomposites

Author(s): Mehdi Asghari, Parvin Nassiri, Mohammad Reza Monazzam, Farideh Golbabaei, Hossein Arabalibeik, Aliakbar Shamsipour and Armin Allahverdy

لینک مشاهده مقاله کامل

Abstract: The main goal of this paper was to investigate transparency and mechano-acoustic properties of poly methyl methacrylate (PMMA)/polycarbonate (PC) based nanocomposites, reinforced with silica (SiO2), zinc dioxide (ZnO), and titanium dioxide (TiO2) nanoparticles. For this purpose, morphological, transparency, acoustical and mechanical tests were carried out on the specimens, prepared by melt-compounding method in a twin-screw extruder. The morphological test results confirmed uniform dispersion of the nanoparticles in the polymer matrix. The results also revealed that transparency of the PC and PMMA nanocomposites, characterized by the degree of light transmittance, was decreased by adding 0.3 wt% of the nanoparticles. Also, tensile modulus of the nanocomposite specimens was higher than that of neat PC and PMMA. Unlike the neat PC specimens, tensile strength showed a decrease in PMMA specimens. The presence of nanoparticles in the composites decreased mobility of polymer chains and consequently, reduced elongation at break in the specimens. After surface roughening process, noise absorption coefficient in PC/PMMA nanocomposite specimens (PCSI3-R, PMSI3-R, and PMZN3-R) showed a higher absorption coefficient than the other specimens in the dominant frequency of traffic noise (500 Hz). As conclusion, roughening the surface of materials would be one of the most important factors enhancing the absorption coefficient of some of the nanocomposites in the middle frequency. The rough surface of particles in the base matrix increases the absorption coefficient of the materials, especially in the frequency of 500 Hz, as the dominant frequency of noise traffic. The suggested materials are predestinated to be appropriate in building industry, particularly in the structure of noise barriers.

Title: Temporal and spatial variation of chemical parameter concentration in drinking water resources of Bandar-e Gaz City using geographic information system

Author(s): Mohammadi, A.A., Yaghmaeian, K. Hossein, F., Nabizadeh, R., Dehghani, M.H., Khaili, J.K., Mahvi, A.H.

لینک مشاهده مقاله کامل

Abstract: One of the serious challenges in ensuring and promoting community health is gradual increase in contamination levels of drinking water of communities across the world. The purposes of this study were (1) to evaluate the chemical quality of groundwater in the Bandar-e Gaz city and (2) to determine spatial distribution of groundwater quality parameters (total hardness (TH), chloride, nitrate and fluoride concentrations, and (3) mapping the quality of groundwater using Geographical Information System (GIS) software. In this study 20 groundwater samples were collected from 5 wells in two successive 2010–2011, in the rainy and dry seasons. Sample preparation and analysis, according to standard methods were done. Based on the findings of this study, it can be expressed that the average concentration chloride and nitrate parameters in Bandar-e Gaz drinking water is within the 1053 standard limit in Iran, except fluoride content is lower than the standard and hardness was high in majority of water sample groundwater. According to the zoning maps of groundwater, in the dry season’s nitrate and hardness concentration is greater than rainy seasonal. The data showed falling and rising trend in CL concentrations, respectively. This study indicated that all parameter within the standard except fluoride then, its necessity to addition fluoride in that’s regions population food chain and drinking water. Management of the utilization and protection greed underground waters should be as a basic principle in the planning Bandar-e Gaz city. © 2017 Desalination Publications. All rights reserved.

Title: Degradation kinetics of tetracycline in aqueous solutions using peroxydisulfate activated by ultrasound irradiation: Effect of radical scavenger and water matrix

Author(s): Simin Nasseri, Amir Hossein Mahvi, Mahdi Seyed salehi, Kamyar Yaghmaeian, Ramin Nabizadeh, Mahmood Alimohammadi, Gholam HosseinSafari

لینک مشاهده مقاله کامل

Abstract: Degradation kinetics of the tetracycline antibiotic in aqueous solution was investigated using sulfate radicals under ultrasound irradiation. The effect of various operational parameters including initial tetracycline concentration, initial peroxydisulfate concentration, solution pH, reaction time, temperature, ultrasound power, the presence of natural organic matter, radical scavenger (tert-butyl alcohol and methanol), as well as the chemical composition of water using ultrapure water, drinking water, and secondary effluent on the degradation efficiency of tetracycline were studied. The preliminary studies were performed using only peroxydisulfate, ultrasound and ultrasound activated peroxydisulfate. The results indicated that tetracycline degradation rate increased with the increase of initial peroxydisulfate concentration, temperature and ultrasonic power, but decreased with the increase of initial tetracycline concentration. The tetracycline degradation rate was highly dependent of initial pH of the solution. The degradation of tetracycline followed the first-order kinetics. The addition of humic acid in concentrations above 10 mg·L− 1 decreased the degradation rate of tetracycline, although the effect could be compensated using higher concentrations of peroxydisulfate. The role of active radicals (sulfate and hydroxyl radicals) was investigated using radical scavengers of methanol and tert-butyl alcohol. Under optimum operational conditions, 96.5% of tetracycline removal was achieved with chemical oxygen demand and total organic carbon removal of about 74% and 61.2%, respectively. The degradation rate of tetracycline was higher in drinking water compared to ultrapure water. Finally, the intermediates were identified and the possible degradation pathway of tetracycline was investigated. Overall, ultrasound activated peroxydisulfate was found to be a promising process for tetracycline degradation in aqueous solutions.

Title: Source apportionment of BTEX compounds in Tehran, Iran using UNMIX receptor model

Author(s): Mohammad Hadi Dehghani, Daryoush Sanaei, Ramin Nabizadeh, Shahrokh Nazmara, Prashant Kumar

لینک مشاهده مقاله کامل

Abstract: Understanding the distribution levels and sources of volatile organic compounds (VOC), mainly benzene, toluene, ethyl benzene and xylenes (BTEX), in the ambient atmosphere is important for efficiently managing and implementing the associated control strategies. We measured BTEX compounds at an industrial location in the west Tehran city (Iran), which is highly influenced by industrial activities and traffic during the winter and spring seasons during 2014–2015. A multivariate receptor model, UNMIX, was applied on the measured data for the identification of the sources and their contributions to BTEX compounds in a highly industrialised and trafficked atmospheric environment of Tehran city. Three main groups of sources were identified. These included solvent and painting sources (e.g. vehicle manufacturing), motorised road vehicles and mixed origin sources. Whilst the solvent and painting sources and vehicle exhaust emissions contributed to about 5 and 29 % of total BTEX mass, respectively, the mixed origin source contributed to about two third (∼66 %) of the remaining mass. These mixed origin sources included rubber and plastic manufacturing (39 %), leather industries (28 %) and the unknown sources (33 %). The mean concentrations of benzene, toluene, ethyl benzene and average xylene (o, p.m.) compounds were measured as 28.96 ± 9.12 μg m−3, 29.55 ± 9.73 μg m−3, 28.61 ± 12.2 μg/m−3 and 25.68 ± 10.58 μg m−3, respectively. A high correlation coefficient (R 2 > 0.94) was also found between predicted (modelled) and measured concentrations for each sample. Further analyses from UNMIX receptor model showed that the average weekday contributions of BTEX compounds were significantly higher during winter compared with those during spring. This higher concentration during winter may be attributed to calm wind conditions and high stability of the atmosphere, along with the after effect of government policies on the use of cleaner fuel in refineries that became operational in winter 2014.