11 research outputs found

    Multiple air pollutant exposure and lung cancer in Tehran, Iran

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    Lung cancer is the most rapidly increasing malignancy worldwide with an estimated 2.1 million cancer cases in the latest, 2018 World Health Organization (WHO) report. The objective of this study was to investigate the association of air pollution and lung cancer, in Tehran, Iran. Residential area information of the latest registered lung cancer cases that were diagnosed between 2014 and 2016 (N = 1,850) were inquired from the population-based cancer registry of Tehran. Long-term average exposure to PM10, SO2, NO, NO2, NOX, benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene (BTEX), and BTEX in 22 districts of Tehran were estimated using land use regression models. Latent profile analysis (LPA) was used to generate multi-pollutant exposure profiles. Negative binomial regression analysis was used to examine the association between air pollutants and lung cancer incidence. The districts with higher concentrations for all pollutants were mostly in downtown and around the railway station. Districts with a higher concentration for NOx (IRR = 1.05, for each 10 unit increase in air pollutant), benzene (IRR = 3.86), toluene (IRR = 1.50), ethylbenzene (IRR = 5.16), p-xylene (IRR = 9.41), o-xylene (IRR = 7.93), m-xylene (IRR = 2.63) and TBTEX (IRR = 1.21) were significantly associated with higher lung cancer incidence. Districts with a higher multiple air-pollution profile were also associated with more lung cancer incidence (IRR = 1.01). Our study shows a positive association between air pollution and lung cancer incidence. This association was stronger for, respectively, p-xylene, o-xylene, ethylbenzene, benzene, m-xylene and toluene

    Multiple air pollutants exposure and leukaemia incidence in Tehran, Iran from 2010 to 2016: a retrospective cohort study

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    OBJECTIVE: Leukaemia is one of the most common cancers and may be associated with exposure to environmental carcinogens, especially outdoor air pollutants. The objective of this study was to investigate the association of ambient air pollution and leukaemia in Tehran, Iran. DESIGN: In this retrospective cohort study, data about the residential district of leukaemia cases diagnosed from 2010 to 2016 were inquired from the Ministry of Health cancer database. Data from a previous study were used to determine long-term average exposure to different air pollutants in 22 districts of Tehran. Latent profile analysis (LPA) was used to classify pollutants in two exposure profiles. The association between air pollutants and leukaemia incidence was analysed by negative binomial regression. SETTING: Twenty-two districts of Tehran megacity. PARTICIPANTS: Patients with leukaemia. OUTCOME MEASURES: The outcome variables were incidence rate ratios (IRR) of acute myeloid and lymphoid leukaemia across the districts of Tehran. RESULTS: The districts with higher concentrations for all pollutants were near the city centre. The IRR was positive but non-significant for most of the air pollutants. However, annual mean NOx was directly and significantly associated with total leukaemia incidence in the fully adjusted model (IRR (95% CI): 1.03 (1.003 to 1.06) per 10 ppb increase). Based on LPA, districts with a higher multiple air-pollutants profile were also associated with higher leukaemia incidence (IRR (95% CI): 1.003 (0.99 to 1.007) per 1 ppb increase). CONCLUSIONS: Our study shows that districts with higher air pollution (nitrogen oxides and multipollutants) have higher incidence rates of leukaemia in Tehran, Iran. This study warrants conducting further research with individual human data and better control of confounding

    Palladium nanoparticles supported on fluorine-doped tin oxide as an efficient heterogeneous catalyst for Suzuki coupling and 4-nitrophenol reduction

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    Immobilization of palladium nanoparticles onto the fluorine-doped tin oxide (FTO) as support Pd/FTO, resulted in a highly active heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions and 4-nitrophenol reduction. The Pd/FTO catalyst has been synthesized by immobilization of palladium nanoparticles onto FTO via a simple impregnation method. ICP-MS analysis confirmed that there is 0.11 mmol/g of palladium was loaded successfully on FTO support. The crystallinity, morphologies, compositions and surface properties of Pd/FTO were fully characterized by various techniques. It was further examined for its catalytic activity and robustness in Suzuki coupling reaction with different aryl halides and solvents. The yields obtained from Suzuki coupling reactions were basically over 80%. The prepared catalyst was also tested on mild reaction such as reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Pd/FTO catalyst exhibited high catalytic activity towards 4-NP reduction with a rate constant of 1.776 min(-1) and turnover frequency (TOF) value of 29.1 hr(-1). The findings revealed that Pd/FTO also maintained its high stability for five consecutive runs in Suzuki reactions and 4-NP reductions. The catalyst showed excellent catalytic activities by using a small amount of Pd/FTO for the Suzuki coupling reaction and 4-NP reduction

    Tracking Climatic Changes Using Glacial Traces and Evidence at Hezar Mountain, Iran

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    Although the current situation of the Iran’s land and the dominance of arid and semiarid conditions cast a doubt on the existence of glacier reign in this land, there is evidence of geomorphological traces of glaciers in different areas of Iran indicating the function of glaciers in these regions. Therefore, regarding these traces and evidences, the past climatic conditions can be reconstructed. Based on what mentioned above, this study mainly aimed to trace the climatic changes through the glacial traces and evidences on the Hezar Mountain. Tracing the climatic changes indicates that the temperature of the study area was 6.58 °C colder than that of the current temperature during the period of glacial reign. In addition, the isopluvial map of the Hezar Mountain during the period of glacial reign indicates that the minimum rainfall at that time was 617 mm at the outlet of the basin and the maximum rainfall was 1340 mm at the highest part of the basin. On the other hand, glacier cirques, glacier valleys, and moraines were identified as the most characteristic geomorphological evidence of glaciers in the study area. Finally, laboratory indicators (granulometry), as a complement to glacier evidence, proved the existence of glacial sediments in the Tenguieh Basin. In addition, the permanent snow line was estimated at the height of 3326 meters in the Tenguieh Basin during the glacial reign and based on Porter’s cirque floor height et the height of 3333 m through the Wright method

    Tracking Climatic Changes Using Glacial Traces and Evidence at Hezar Mountain, Iran

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    Although the current situation of the Iran’s land and the dominance of arid and semiarid conditions cast a doubt on the existence of glacier reign in this land, there is evidence of geomorphological traces of glaciers in different areas of Iran indicating the function of glaciers in these regions. Therefore, regarding these traces and evidences, the past climatic conditions can be reconstructed. Based on what mentioned above, this study mainly aimed to trace the climatic changes through the glacial traces and evidences on the Hezar Mountain. Tracing the climatic changes indicates that the temperature of the study area was 6.58 °C colder than that of the current temperature during the period of glacial reign. In addition, the isopluvial map of the Hezar Mountain during the period of glacial reign indicates that the minimum rainfall at that time was 617 mm at the outlet of the basin and the maximum rainfall was 1340 mm at the highest part of the basin. On the other hand, glacier cirques, glacier valleys, and moraines were identified as the most characteristic geomorphological evidence of glaciers in the study area. Finally, laboratory indicators (granulometry), as a complement to glacier evidence, proved the existence of glacial sediments in the Tenguieh Basin. In addition, the permanent snow line was estimated at the height of 3326 meters in the Tenguieh Basin during the glacial reign and based on Porter’s cirque floor height et the height of 3333 m through the Wright method

    Combining artificial neural networks and genetic algorithms for rock cuttings slopes stability condition identification

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    Keeping large-scale transportation infrastructure networks, such as railway net-works, operational under all conditions is one of the major challenges today. The budgetary constraints for maintenance and network operation and the network dimension are two of the main factors that make the management of a transporta-tion network such a challenging task. Hence, aiming to assist the management of a transportation network, a data-driven model is proposed for stability condition identification of rock cuttings slopes. It should be noted that one of the key points of the proposed system is to avoid data from complex monitoring equipment or laboratory expensive testes. Accordingly, only information taken from routine in-spections (visual information) and complemented with geometric and geologic data will be used to feed the models. Therefore, in this work the flexible learning capabilities of Artificial Neural Networks (ANN) were used to fit a data-driven model for Earthwork Hazard Category (EHC) identification. Considering the high number of parameters involved in EHC identification, Genetic Algorithms (GA) were applied for input feature selection purposes. The proposed models were addressed following a nominal classification strategy. In addition, to over-come the problem of imbalanced data (since typically good conditions are much common than bad ones), three training sampling approaches were explored: no resampling, SMOTE and Oversampling. The achieved modelling results are pre-sented and discussed, detailing GA effectiveness and ANNs performance.This work was supported by FCT - “Fundação para a Ciência e a Tecnologia”, within Institute for Sustainability and Innovation in Structural Engineering (ISISE), project UID/ECI/04029/2013 as well Project Scope: UID/CEC/00319/2013 and through the post-doctoral Grant fellowship with reference SFRH/BPD/94792/2013. This work was also partly financed by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT within the scope of the project POCI-01-0145-451 FEDER-007633. This work has been also supported by COMPETE: POCI-01-0145- FEDER-007043. A special thanks goes to NetworkRail that kindly made available the data (basic earthworks examination data and the Earthworks Hazard Condition scores) used in this work
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