Atmosphere Of Urban Areas Research Articles

How do urban policies shape atmosphere? A multimethod inquiry of the sonic environment

ABSTRACT The effect of urban policies on the atmosphere of urban areas is rarely documented. Mobilizing the concept of atmosphere, this article takes a sonic lens to put forward a sensorial understanding of how urban policies shape city users’ sonic experiences and impact the perceived liveliness and attractiveness of public spaces. Reporting on a case study in Mestre (Venice, Italy), we study the effect of two urban policies on the sonic environments in the historic center and on the uses of public space within its pedestrianized area. Through surveys, interviews and recordings, we show how urban policies contribute to the formation of atmosphere.

Breathing Fresh Air in the City: Implementing Avenue Trees as a Sustainable Solution to Reduce Particulate Pollution in Urban Agglomerations.

The issue of air pollution from particulate matter (PM) is getting worse as more and more people move into urban areas around the globe. Due to the complexity and diversity of pollution sources, it has long been hard to rely on source control techniques to manage this issue. Due to the fact that urban trees may provide a variety of ecosystem services, there is an urgent need to investigate alternative strategies for dramatically improving air quality. PM has always been a significant concern due to its adverse effects on humans and the entire ecosystem. The severity of this issue has risen in the current global environmental context. Numerous studies on respiratory and other human disorders have revealed a statistical relationship between human exposure to outdoor levels of particles or dust and harmful health effects. These risks are undeniably close to industrial areas where these airborne, inhalable particles are produced. The combined and individual effects of the particle and gaseous contaminants on plants' general physiology can be detrimental. According to research, plant leaves, the primary receptors of PM pollution, can function as biological filters to remove significant amounts of particles from the atmosphere of urban areas. This study showed that vegetation could provide a promising green infrastructure (GI) for better air quality through the canopy and leaf-level processes, going beyond its traditional role as a passive target and sink for air pollutants. Opportunities exist for urban GI as a natural remedy for urban pollution caused by PMs.

Air Quality Impact Estimation Due to Uncontrolled Emissions from Capuava Petrochemical Complex in the Metropolitan Area of São Paulo (MASP), Brazil

In the second quarter of 2021, the companies at the Capuava Petrochemical Complex (CPC, Santo André, Brazil) carried out a 50-day scheduled shutdown for the maintenance and installation of new industrial equipment. This process resulted in severe uncontrolled emissions of particulate matter (PM) and volatile organic compounds (VOCs) in a densely populated residential area (~3400 inhabitants/km2). VOCs can be emitted directly into the atmosphere in urban areas by vehicle exhausts, fuel evaporation, solvent use, emissions of natural gas, and industrial processes. PM is emitted by vehicle exhausts, mainly those powered by diesel, industrial processes, and re-suspended soil dust, in addition to that produced in the atmosphere by photochemical reactions. Our statistical analyses compared the previous (2017–2020) and subsequent (2021–2022) periods from this episode (April–May 2021) from the official air quality monitoring network of the PM10, benzene, and toluene hourly data to improve the proportion of this period of uncontrolled emissions. Near-field simulations were also performed to evaluate the dispersion of pollutants of industrial origin, applying the Gaussian plume model AERMOD (steady-state plume model), estimating the concentrations of VOC and particulate matter (PM10) in which the population was exposed in the region surrounding the CPC. The results comparing the four previous years showed an increase in the mean concentrations by a factor of 2 for PM10, benzene, and toluene, reaching maximum values during the episode of 174 µg m−3 (PM10), 79.1 µg m−3 (benzene), and 58.7 µg m−3 (toluene). Meanwhile, these higher concentrations continued to be observed after the episode, but their variation cannot be fully explained yet. However, it is worth highlighting that this corresponds to the post-pandemic period and the 2022 data also correspond to the period from January to June, that is, they do not represent the annual variation. A linear correlation indicated that CPC could have been responsible for more than 60% of benzene measured at the Capuava Air Quality Station (AQS). However, the PM10 behavior was not fully explained by the model. AERMOD showed that the VOC plume had the potential to reach a large part of Mauá and Santo André municipalities, with the potential to affect the health of more than 1 million inhabitants.

Seasonal Variations of Particulate Matter Capture and the Air Pollution Tolerance Index of Five Roadside Plant Species

Particulate matter (PM) is the most dangerous type of air pollutant and is harmful to human health. Plants can be used as a biofilter to remove PM from the atmosphere and improve air quality. In this study, we used the air pollution tolerance index and four leaf traits of five different plant species commonly used in landscaping in Korea to determine which plants are best suited to remove PM from the atmosphere in roadside areas in spring, summer, and autumn. We found that the PM concentrations in the atmosphere impacted the amount of PM accumulated in the plants, with increased PM accumulation during periods of increased environmental PM levels on the roadside. Euonymus japonicus, and Euonymus alatus accumulated the highest amount of PM and had the highest tolerance levels to air pollution. Thus, these species could be suitable for use in areas with high PM concentrations to improve air quality. We also found that shrubs were more effective in accumulating PM than trees and recommend that shrubs and trees be used together to further increase the amount of PM removed from the atmosphere in urban areas.

Impact of separately located obstacles on air flow movement calculation

In hydrodynamic calculations, the confederation of the right set of coordinates of a continuous medium (gas, liquid) becomes complicated because it makes the calculation mechanismspecific and tied only to a specific object. The paper is devoted to an improved method to calculate the small-scale circulation of the surface layer of the atmosphere in urban areas with many isolated buildings from each other. The proposed method will work for explicit and implicit schemes for calculating the transport equations and conservation of momentum of motion. It is designed to calculate the small-scale circulation of the surface layer of the atmosphere in urban areas with many isolated buildings from each other. The method allows for consideration of the interaction of a continuous medium flow with impenetrable obstacles discretely and randomly located inside the calculation area. This method will be helpful when calculating microcirculation in urban development.

Use of unmanned aerial systems for measuring particulate matter in the lower atmosphere in urban areas

Air quality monitoring traditionally relies on ground stations and satellites, which may face limitations in capturing real-time data near pollution sources due to site complexity or physical barriers. To overcome these challenges, unmanned aerial vehicles (UAVs) equipped with air quality sensors offer new opportunities for comprehensive and rapid data collection in urban and industrial areas. In this study, we propose a novel approach by utilizing a UAV-based system to investigate the spatial distribution of particulate matter in the atmosphere. The monitoring site is strategically located at an intersection in Zagreb, known for its medium to high traffic density and its suitability for capturing the impact of vehicular emissions on air quality. It is essential to note that this assumption based on the observed conditions is not a precisely measured figure but rather an estimate based on observations and the context of the road. Traffic density may vary throughout the day, week, or year, depending on working hours, events, seasonal factors, and other influences affecting vehicular movement. The UAV is equipped with lightweight and low-cost sensors specifically designed for measuring airborne particles, ensuring accurate and reliable measurements. These sensors, integrated onto the UAV and placed on the upper side, minimize interference from propeller-generated airflow and turbulence, providing representative assessments of air quality conditions. By collecting precise data on the concentration of airborne particles, including PM1, PM2.5, and PM10, the study aims to gain insights into the spatial distribution of pollutants near the intersection and understand the potential impacts of traffic emissions on the surrounding environment. Additionally, the UAV's sensors can connect to smartphones or computers, enabling real-time data viewing and analysis, facilitating prompt adjustments and informed decision-making based on the current air quality conditions. The findings challenge the initial assumption as the concentration of particles does not decrease with increasing altitude, requiring further research to understand this phenomenon. Furthermore, future research will consider integrating meteorological data, such as temperature, humidity, air pressure, wind direction, and speed, from a nearby weather station. By analyzing the interplay between meteorological parameters and particle concentration, a comprehensive understanding of airborne particle dynamics can be achieved. This approach will contribute to the development of effective strategies for managing air quality, considering the complex interdependencies and factors influencing particle distribution in the air.

Observations of aerosol optical properties during tropical forest fires in Indonesia

This study aims to determine the direct effect of aerosol on one element of the radiation energy balance that includes short-wavelength (SW). The AOD data from the Moderate Resolution Imaging Spectroradiometer, MODIS level 3 instrument, Terra satellite, and the Clouds and Earth's Radiant Energy System (CERES) radiation component instrument were obtained to observe the spatial and temporal variations in the aerosol optical depth (AOD) at 550 nm and their relationship to the radiation balance element. These data were analyzed from January 2000 to April 2019 in Indonesia. The results of the analysis show that the average daily temporal fluctuation of AOD showed a respectively high value, namely 1.03 on 23 October 2015 and 0.68 on 9 October 2006. This very high AOD value was closely related to forest fires in Sumatra and Kalimantan. The immediate reaction in Kalimantan was when there was an increase in the accumulation of aerosol particles in the atmosphere in urban areas in this region, namely Palangka Raya, Pontianak and Banjarmasin. From the results of processing using the scatter plot statistical method, the relationship between AOD and SW obtained a negative correlation value (r) which was quite high for Pontianak with r = 0.62.

Outdoor Atmospheric Microbial Diversity Is Associated With Urban Landscape Structure and Differs From Indoor-Transit Systems as Revealed by Mobile Monitoring and Three-Dimensional Spatial Analysis

Microbes are abundant inhabitants of the near-surface atmosphere in urban areas. The distribution of microbial communities may benefit or hinder human wellbeing and ecosystem function. Surveys of airborne microbial diversity are uncommon in both natural and built environments and those that investigate diversity are stationary in the city, thus missing continuous exposure to microbes that covary with three-dimensional urban structure. Individuals in cities are generally mobile and would be exposed to diverse urban structures outdoors and within indoor-transit systems in a day. We used mobile monitoring of microbial diversity and geographic information system spatial analysis, across Philadelphia, Pennsylvania, USA in outdoor and indoor-transit (subways and train cars) environments. This study identifies to the role of the three-dimensional urban landscape in structuring atmospheric microbiomes and employs mobile monitoring over ~1,920 kilometers to measure continuous biodiversity. We found more diverse communities outdoors that significantly differ from indoor-transit air in microbial community structure, function, likely source environment, and potentially pathogenic fraction of the community. Variation in the structure of the urban landscape was associated with diversity and function of the near-surface atmospheric microbiome in outdoor samples.

Analyzing of usability of tree-rings as biomonitors for monitoring heavy metal accumulation in the atmosphere in urban area: a case study of cedar tree (Cedrus sp.).

It is important to monitor the heavy metal pollution in order to identify risk zones and to determine the change in the heavy metal concentration of the atmosphere within the process. For this, it is necessary to carry out measurements for many years; however, this is not possible. Especially from past to present, one of the most effective methods to determine the changes of heavy metal concentrations in the atmosphere is to use the annual tree rings as biomonitors. Perennial plants growing in our country create annual rings, and it is possible to gain information regarding the changes of heavy metal concentrations in that region by determining the heavy metal concentrations in these rings. In this study, it was aimed to determine the annual changes of Pb, Co, and Fe elements' concentrations in these sections by determining the annual rings on the logs taken from the main stem of the cedar tree (Cedrus sp.), which was cut by the end of 2016, in December, 2016, in Kastamonu province. Within the scope of the study, the element concentrations were also determined in the inner and outer bark. As a result of the study, it was found that the heavy metal values in the organelles taken from the road-facing part, especially the heavy metal concentrations in the outer bark were higher than the metal concentrations in the inward-facing part, and that the concentrations changed significantly on organelle and year basis.

Particulate Matter from the Road Surface Abrasion as a Problem of Non-Exhaust Emission Control

Along with house heating and industry, emissions from road traffic (exhaust and tire, brake, car body or road surface abrasions) are one of the primary sources of particulate matter (PM) in the atmosphere in urban areas. Though numerous regulations and vehicle-control mechanisms have led to a significant decline of PM emissions from vehicle exhaust gases, other sources of PM remain related to road and car abrasion are responsible for non-exhaust emissions. Quantifying these emissions is a hard problem in both laboratory and field conditions. First, we must recognize the physicochemical properties of the PM that is emitted by various non-exhaust sources. In this paper, we underline the problem of information accessibility with regards to the properties and qualities of PM from non-exhaust sources. We also indicate why scarce information is available in order to find the possible solution to this ongoing issue.

The Attenuation of Free Space Optical Communication under Dusty Conditions in Lahore

FSO (free space optical) communication is one of the most advanced modes of wireless communication. FSO is a line of sight communication which is used to convey data from an optical transmitter to an optical receiver through atmosphere. FSO offers higher data rates but fading level due to atmospheric effects (like sand, dust, fog, rain, snow etc.) are higher than RF (radio frequency) technology. The atmosphere affects the laser beam passing through it. The atmospheric turbulence and scattering results in the degradation of the signal. In this research paper is focused and analyzes the variations in the visibility and attenuation with respect to the concentration of aerosol particles (suspended elemental particles) is done. This research work is conducted and dust model is designed in the atmosphere of urban area of Lahore city. The model deals the effect of the size of the dust particles on the visibility of FSO link and suggests a formula for the calculation of attenuation generated in the link.

Impacts of Anthropogenic Heat on Summertime Rainfall in Beijing

AbstractAnthropogenic heat is an important component of the urban energy budgets that can affect land surface and atmospheric boundary layer processes. Representation of anthropogenic heat in numerical climate modeling systems is therefore important when simulating urban meteorology and climate and has the potential to improve weather forecasts, climate process studies, and energy demand analysis. Here, spatiotemporally dynamic anthropogenic heat data estimated by the Building Effects Parameterization and Building Energy Model (BEP-BEM) are incorporated into the Weather Research and Forecasting (WRF) Model system to investigate its impact on simulation of summertime rainfall in Beijing, China. Simulations of four local rainfall events with and without anthropogenic heat indicate that anthropogenic heat leads to increased rainfall over the urban area. For all four events, anthropogenic heat emission increases sensible heat flux, enhances mixing and turbulent energy transport, lifts PBL height, increases dry static energy, and destabilizes the atmosphere in urban areas through thermal perturbation and strong upward motion during the prestorm period, resulting in enhanced convergence during the major rainfall period. Intensified rainfall leads to greater atmospheric dry-down during the storm and a higher poststorm LCL.

Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Atmospheric Environment of Urban Areas in Latin America

ABSTRACTPolycyclic aromatic hydrocarbons (PAHs) are chemical compounds considered as pollutants of high priority due to their carcinogenic potential. PAH can appear in water, soil or in the atmosphere as adsorbed on particulate material or in gas phase. An increased number of studies on atmospheric PAH in urban areas have been published in the last decade, especially in the last years. Anthropogenic sources are frequently mentioned to be responsible for the increased concentration of PAHs in the atmosphere of urban areas, which at the same time seems to depend on meteorological parameters. This research is focused on compiling information on PAH levels in Latin America and their relationship with typical meteorological variables from seasonal and tropical countries. Brazil is the country with the most number of bibliographies about this topic, followed by Argentina, Chile and Mexico. Scarce information was found for Colombia and Venezuela and none for the rest of Latin American countries. The majority of studies checked have evaluated the climatological parameters in relationship with the PAH concentration and their distribution, finding that it affects meaningfully their levels. The monitor campaigns in Brazil have been developed mainly in the southern cities, where PAHs are strongly influenced by the seasons and their proximity to the South Pole. Tropical countries such as Venezuela and Colombia showed moderate variation of PAH concentration through months. The main influential parameters are precipitation and direction/speed winds.

Foliar uptake and metal(loid) bioaccessibility in vegetables exposed to particulate matter.

At the global scale, high concentrations of particulate matter (PM) enriched with metal(loid)s are currently observed in the atmosphere of urban areas. Foliar lead uptake was demonstrated for vegetables exposed to airborne PM. Our main objective here was to highlight the health risk associated with the consumption of vegetables exposed to foliar deposits of PM enriched with the various metal(loid)s frequently observed in the atmosphere of urban areas (Cd, Sb, Zn and Pb). Leaves of mature cabbage and spinach were exposed to manufactured mono-metallic oxide particles (CdO, Sb2O3 and ZnO) or to complex process PM mainly enriched with lead. Total and bioaccessible metal(loid) concentrations were then measured for polluted vegetables and the various PM used as sources. Finally, scanning electronic microscopy coupled with energy dispersive X-ray microanalysis was used to study PM-phyllosphere interactions. High quantities of Cd, Sb, Zn and Pb were taken up by the plant leaves. These levels depended on both the plant species and nature of the PM, highlighting the interest of acquiring data for different plants and sources of exposure in order to better identify and manage health risks. A maximum of 2% of the leaf surfaces were covered with the PM. However, particles appeared to be enriched in stomatal openings, with up to 12% of their area occupied. Metal(loid) bioaccessibility was significantly higher for vegetables compared to PM sources, certainly due to chemical speciation changes. Taken together, these results confirm the importance of taking atmospheric PM into account when assessing the health risks associated with ingestion of vegetables grown in urban vegetable crops or kitchen gardens.

Effects of anthropogenic heat on ozone air quality in a megacity

Anthropogenic heat released into the atmosphere in urban areas affects the characteristics/structures of boundary layer and local circulation and thus can affect local air quality. In this study, the effects of anthropogenic heat on ozone (O3) air quality in the Seoul metropolitan area, Republic of Korea, are examined using the Community Multiscale Air Quality (CMAQ) model coupled with the Weather Research and Forecasting (WRF) model. The release of anthropogenic heat is found to increase O3 concentration by 3.8 ppb in the urban area, and this effect is larger in the nighttime (5.3 ppb) than in the daytime (2.4 ppb). As stronger anthropogenic heat is released, the urban boundary layer becomes deeper and NOx concentration becomes lower due to the dilution. The decrease in NOx concentration causes the chemical loss of O3 by the reaction with NO to be reduced. In addition to the enhanced net chemical production of O3 in the deepened urban boundary layer, the strengthened urban-breeze circulation by anthropogenic heat contributes to an increase in O3 concentration in the urban area. The O3-rich air in the surroundings of Seoul, where biogenic volatile organic compound (BVOC) emissions are high and NOx emissions are low, is brought into the urban area by the urban breeze. Moreover, in the daytime, the advection of oxidant products of BVOCs by the urban breeze contributes to an enhanced chemical production of O3 in the urban area. Anthropogenic heat also modifies the sea/land-breeze circulations, which, in turn, is found to influence O3 concentration in the urban area.

Impact of Fe Content in Laboratory-Produced Soot Aerosol on its Composition, Structure, and Thermo-Chemical Properties

Soot aerosol, which is a major pollutant in the atmosphere of urban areas, often contains not only carbonaceous matter but also inorganic material. These species, for example, iron compounds, originated from impurities in fuel or lubricating oil, additives or engine wear may change the physico-chemical characteristics of soot and hence its environmental impact. We studied the change of composition, structure, and oxidation reactivity of laboratory-produced soot aerosol with varying iron content. Soot types of various iron contents were generated in a propane/air diffusion flame by adjusting the doping amount of iron pentacarbonyl Fe(CO)5 to the flame. Scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX) was combined with cluster analysis (CA) to separate individual particles into definable groups of similar chemical composition representing the particle types in dependence of the iron content in soot. Raman microspectroscopy (RM) and infrared spectroscopy were applied for the char...

Metallic elements and isotope of Pb in wet precipitation in urban area, South America

The atmosphere of urban areas has been the subject of many studies to show the atmospheric pollution in large urban centers. By quantifying wet precipitation through the analysis of metallic elements (ICP/AES) and Pb isotopes, the wet precipitation of the Metropolitan Area of the Porto Alegre (MAPA), Brazil, was characterized. The samples were collected between July 2005 and December 2007. Zn, Fe and Mn showed the highest concentration in studied sites. Sapucaia do Sul showed the highest average for Zn, due to influence by the steel plant located near the sampling site. The contribution of anthropogenic emissions from vehicular activity and steel plants in wet precipitation and suspended particulate matter in the MAPA was identified by the isotopic signatures of 208Pb/207Pb and 206Pb/207Pb. Moreover the analyses of the metallic elements allowed also to identify the contribution of other anthropic sources, such as steel plants and oil refinery.

Polycyclic Aromatic Hydrocarbons in Air

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds consisting of two or more condense aromatic rings. They are products of incomplete combustion or pyrolysis of organic matter. Because some PAHs such as Benzo[a]pyrene (BaP) are proven carcinogens and mutagens, it is necessary to continuously monitor their concentrations in the air, water, and soil. PAHs with two or three aromatic rings are stable in the gas phase, while most PAHs with five or more aromatic rings bond to particles. Higher concentrations of PAHs are present in the atmosphere of urban areas, mostly in the winter, due to heating. In the summer, these concentrations drop because most PAHs are unstable at high temperatures and break down by oxidation and photooxidation. Measurements of PAHs in the air include sampling on the filter paper or solid adsorbent, extraction, and chromatographic analysis. This review presents the measurements of BaP in some locations in the world and compares them with the findings in Croatia.

Quantification of sources of PCBs to the atmosphere in urban areas: A comparison of cities in North America, Western Europe and former Yugoslavia

We present estimated emission source strengths of seven polychlorinated biphenyl (PCB) congeners for Banja Luka, a city that was affected by the civil war in Bosnia and Hercegovina (former Yugoslavia) in the 1990s. These emission estimates are compared to PCB emission rates estimated for the cities of Zurich, Switzerland, and Chicago, USA using an approach that combines multimedia mass balance modeling and measurement data. Our modeled per-capita emission estimates for Banja Luka are lower by a factor of ten than those for Zurich and Chicago, which are similar. This indicates that the sources of PCB emissions in Banja Luka are likely to be weaker than in the Western European and North American cities which show relatively high PCB emissions. Our emission rates from the three cities agree within a factor of ten with emission estimates from a global PCB emission inventory derived from production and usage estimates and emission factors.

A neural net-air dispersion model validation study using the Indianapolis urban data set

It is presented an integrated model composed by a dispersion model and a Neural Net (NN). The NN uses the concentrations predicted by the an analytical dispersion model as input variables of the net. This methodology was validated using Indianapolis urban data set where releases from an elevated emission source were considered. An improvement of performances is shown when the neural network is added downstream to the dispersion model. Tests reveal the system is able to reproduce the expected behaviour of pollutant concentration, with the downwind distance and stability of the atmosphere in urban area.