Modeling the emission and calculation of the risk of steelmaking contaminants using the AERMOD model

Background and Aims: Nowadays, air pollution has become a major challenge especially in large cities. Considering the paramount importance of air pollutants impact of human health, the study of pollutants emission models to estimate their dispersion and consequent impacts on human health is very important.Materials and Methods: In this research, CO, NO2 and SO2 emissions from steel complexes, which are the most important pollutants of this industry, is discussed. For this purpose, AERMOD models have been designed to investigate the dispersion of pollutants and then BREEZE AERMOD model to study the risk of emission of pollutants. Finally, the risk of pollutants inhalation was estimated using the RAIS model. The data were collectedstatistically. All stages of this research were conducted ethically and relevant permits were obtained.Results: According to the calculations made in our study, the risk factor for non-cancerous inhalation of air pollutants in the steel complex was 3.7 for employees, 4.8 for workers and 7.7 for office workers, 3.7 for over-threshold workers. These individuals were at risk caused by contaminants, especially carbon monoxide and nitrogen dioxide.Residents in the neighbor regions demonstrating a risk index of 0.2% are at a lower risk.Conclusion: Considering the risk assessments made, emissions from steel complexes pose a serious health risk specially for workers. Indeed, due to the close proximity of the surrounding villages in the southern areas of the site to the steel complex flares, they are exposed to the large amounts of contaminants.Keywords: steel complex, air pollution modeling, breeze aermod, aermod, rias method

Simulation of conjugate radiation-forced convection heat transfer in a porous medium using the lattice Boltzmann method

In this paper, a lattice Boltzmann method is employed to simulate the conjugate radiation–forced convection heat transfer in a porous medium. The absorbing, emitting, and scattering phenomena are fully included in the model. The effects of different parameters of a silicon carbide porous medium including porosity, pore size, conduction–radiation ratio, extinction coefficient and kinematic viscosity ratio on the temperature and velocity distributions are investigated. The convergence times of modified and regular LBMs for this problem are 15 s and 94 s, respectively, indicating a considerable reduction in the solution time through using the modified LBM. Further, the thermal plume formed behind the porous cylinder elongates as the porosity and pore size increase. This result reveals that the thermal penetration of the porous cylinder increases with increasing the porosity and pore size. Finally, the mean temperature at the channel output increases by about 22% as the extinction coefficient of fluid increases in the range of 0–0.03

Spatial analysis of CO and PM10 pollutants in Tehran city

     Nowadays, air pollution in cities with regard to its harmful outcomes has been turned into one of the serious challenges in urban management. Pollutants as Carbon monoxide, sulfur dioxide, and the aerosols that are known to be among the most important factors related to heart, vascular, and lung disease, have underlined public welfare and health, and the organizations concerned with community health undertake remarkable expenses for disease coming out of these pollutants per year. Awareness of the air situation and its quality over periods and the process of air pollutants’ changes in locations, and especially detection of high risk places can play an important and efficient role in urban health management and land use policy-making. In this paper, for the prediction of the possibility of occurring a pollutant in different locations, based on location information, one modern method of analysis entitled indicator kriging method is introduced. Since, nowadays, CO and PM10 are the two major pollutants in Tehran city, using the mentioned method, the probability of occurrence of each of them in Dey 1390 along with their accuracy is being measured and then a map is provided for the possible occurrence of these pollutants over the whole city of Tehran. 

Feasibility of Improvement of the Filter Performance of Particle Filtering Respirators by Using Composite Media of Polyacrylonitrile Nanofiber (PAN) and Montmorillonite Clay Nanoparticles (MMT)

Introduction: The important parameters for evaluating the performance of particle filtering respirators in international standards are the filtration efficiency and respiratory resistance of the mask filter against airflow passage. To improve nanofiber filtration efficiency while creating the least breathing difficulty for the wearer, various research has been or is being conducted worldwide. This study investigated the effect of using polyacrylonitrile (PAN) nanofiber composite membrane and montmorillonite clay nanoparticles (MMT) in enhancing particle-filtering respirators’ filter performance, achieving higher filtration efficiency while maintaining optimal respiratory resistance conditions. Material and Methods: First, PAN polymer solution containing zero, 1%, 2%, 3%, and 5% MMT nanoparticles was prepared, and then PAN/MMT nanofiber composite membrane was synthesized in an electrospinning machine. Filtration efficiency was measured in diameter range of 0.3, 0.5, 1, and 3 microns using sodium chloride aerosol. Additionally, filter breathing resistance was measured at flow rates of 30, 85, and 95 liters per minute. Results: The efficiency of synthesized composite nanofilters for particle purification can be improved by adding MMT nanoparticles to PAN nanofibers. Optimal MMT concentration was found to be 2%. This addition resulted in an increase in filtration efficiency for particles with sizes of 0.3, 0.5, 1, and 3 microns by 4.2%, 4.88%, 3.77%, and 2.75% respectively without causing significant difference in respiratory resistance. Improved filtration efficiency can be attributed to enhanced morphology of composite nanofilters resulting from addition of MMT nanoparticles. Adding 2% MMT nanoparticles to PAN nanofibers resulted in uniform distribution and smaller fiber dimensions which did not significantly affect Packing density and porosity. Conclusion: If 2% of MMT nanoparticles are added to PAN nanofibers and used to produce particle respirators, resulting respirator will exhibit a 4.2% increase in particle filtration efficiency without increasing breathing difficulty for user. This result can help protect users from particulate pollutants in air pollution conditions

Analytical Decision Supports System for Urban Air Quality Management in Tehran: Meteorological and Photochemical models

A new analytical air pollution modeling system is introduced in this paper to estimate concentrations of primary and secondary air pollutants and using it for further studies in order to improve the knowledge of pollutants emission and dispersion over Tehran, and developing a decision support system. For this purpose, WRF/CAMx modeling system was used to simulate the gas-phase pollutants concentrations including primary and secondary pollutants, over Tehran during a wintertime episode, which is characterized by very high concentrations of pollutants. Pollutants were triggered by meteorological conditions leading to a forced holiday imposed on citywide operations to protect the health of citizens. Based on calculated Values of NMB error, WRF performs acceptable in predicting temperature and wind speed. Generally, time series plots show that WRF performs acceptable in mild selected episode. Also, the daily trends of pollutant concentrations are greatly affected by changes in local meteorological conditions such as planetary boundary layer (PBL) height, temperature, wind, and relative humidity over the Tehran area. An underestimation in prediction of all pollutants concentrations episode at Poonak and Aghdasyeh sites show due to the insufficient emission data at the site position used for the simulation were seen. Results showed that WRF/CAMx modeling system proved to be a useful tool for analyzing urban environmental problems, investigating the impact of air quality control policies, and predicting critical conditions. However, there were weaknesses in input data and modeling system calibration that should be improved before using the system for further studies

Magnetic Resonance Imaging (MRI): Emphasis may be Placed on New Developments in MRI Techniques, such as Functional Magnetic Resonance Imaging (FMRI) or Dynamic Contrast-Enhancing MRI (DCE-MRI)

Magnetic Resonance Imaging (MRI) has revolutionized medical diagnostics by providing detailed images of soft tissues without using ionizing radiation. In recent years, there has been a growing emphasis on advancing MRI techniques to enhance both anatomical and functional imaging capabilities. Two notable developments are **functional MRI (fMRI)** and **dynamic contrast-enhanced MRI (DCE-MRI) Functional MRI (fMRI) - Principles: fMRI detects changes in blood flow associated with neural activity. It relies on the blood-oxygen-level-dependent (BOLD) contrast. - Applications: - Brain mapping: Identifying regions responsible for motor, language, and memory functions. - Cognitive neuroscience: Investigating brain processes during tasks. - Neurological disorders: Assisting in epilepsy surgery planning and tumor localization. - Challenges: Addressing spatial and temporal resolution limitations and minimizing motion artifacts. Dynamic Contrast-Enhanced MRI (DCE-MRI) - Mechanism: DCE-MRI uses gadolinium-based contrast agents to assess tissue vascularity and permeability. - Clinical Applications: - Brain tumors: Characterizing neoplastic lesions and predicting treatment response. - Head and neck cancer: Early recurrence detection and treatment guidance. - Quantitative Analysis: Efforts toward standardization and refinement continue

Impact of Climate Change on Medical Emergency Incidents and Responses

Climate change has and will create new patterns of emergency incidents and burden the existing patterns. These patterns will be created by the predicted changes in meteorological and hydrological disasters, particularly extreme events. At the most direct level, extreme events are more likely to cause death and injury, and it is possible to predict what changes in the incidence of various health outcomes would occur. An example of prediction methodology is using the change in the incidence of heat-related health outcomes as a function of the magnitude and timing of climate change. Heat and/or sudden changes in temperature levels are more complex to predict the effect, yet the increased variance of greater frequency and intensity of high-temperature events will cause a higher incidence of acute events such as myocardial infarction and chronic events with rapid decompensation such as decompensated heart failure. Temperature change can also amplify the severity of many of today\u27s most common disasters. An example of this is the predicted increase in flash floods due to the increased incidence of heavy rainfalls and convective rainstorms, which are often associated with a rapid rise in local precipitation and can cause catastrophic damage to life and society. Wildfire is another health-damaging event that is certainly set to increase in incidence, being very dependent on temperature and soil moisture. This event is predicting the change in the global distribution of wildfires and possible health outcomes. Yet, it is widely known that the effects in many MEDCs will burden the resources of local health services without having to consider global impacts. An example of this is wildfires in Southern France. It is known to cause mass respiratory casualties, yet the lack of studies means it is unclear as to the exact consequences and proper allocation of prehospital care. Climate change is increasingly recognized as an important aspect of human health because the health of communities is affected by physical, chemical, and biological changes. These changes impact systems, communities, and individuals differently. The impacts are distributed in geographical areas that are already burdened by disease and poor health. This study attempts to understand a range of impacts of climate change on medical emergency incidents and responses in terms of epidemiology, changes in the location and frequency of various emergencies, and the consequences of prehospital care. Paris and the remainder of France are used as case studies due to the presence of detailed databases and the range of climate seen in this one country

Global Air Quality and COVID-19 Pandemic : Do We Breathe Cleaner Air?

The global spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has challenged most countries worldwide. It was quickly recognized that reduced activities (lockdowns) during the Coronavirus Disease of 2019 (COVID-19) pandemic produced major changes in air quality. Our objective was to assess the impacts of COVID-19 lockdowns on groundlevel PM2.5, NO2, and O-3 concentrations on a global scale. We obtained data from 34 countries, 141 cities, and 458 air monitoring stations on 5 continents (few data from Africa). On a global average basis, a 34.0% reduction in NO2 concentration and a 15.0% reduction in PM2.5 were estimated during the strict lockdown period (until April 30, 2020). Global average O-3 concentration increased by 86.0% during this same period. Individual country and continent-wise comparisons have been made between lockdown and business-as-usual periods. Universally, NO2 was the pollutant most affected by the COVID-19 pandemic. These effects were likely because its emissions were from sources that were typically restricted (i.e., surface traffic and non-essential industries) by the lockdowns and its short lifetime in the atmosphere. Our results indicate that lockdown measures and resulting reduced emissions reduced exposure to most harmful pollutants and could provide global-scale health benefits. However, the increased O-3 may have substantially reduced those benefits and more detailed health assessments are required to accurately quantify the health gains. At the same, these restrictions were obtained at substantial economic costs and with other health issues (depression, suicide, spousal abuse, drug overdoses, etc.). Thus, any similar reductions in air pollution would need to be obtained without these extensive economic and other consequences produced by the imposed activity reductions.Peer reviewe

Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin