Showing papers on "Air quality index published in 2013"

U-Air: when urban air quality inference meets big data

Abstract: Information about urban air quality, e.g., the concentration of PM2.5, is of great importance to protect human health and control air pollution. While there are limited air-quality-monitor-stations in a city, air quality varies in urban spaces non-linearly and depends on multiple factors, such as meteorology, traffic volume, and land uses. In this paper, we infer the real-time and fine-grained air quality information throughout a city, based on the (historical and real-time) air quality data reported by existing monitor stations and a variety of data sources we observed in the city, such as meteorology, traffic flow, human mobility, structure of road networks, and point of interests (POIs). We propose a semi-supervised learning approach based on a co-training framework that consists of two separated classifiers. One is a spatial classifier based on an artificial neural network (ANN), which takes spatially-related features (e.g., the density of POIs and length of highways) as input to model the spatial correlation between air qualities of different locations. The other is a temporal classifier based on a linear-chain conditional random field (CRF), involving temporally-related features (e.g., traffic and meteorology) to model the temporal dependency of air quality in a location. We evaluated our approach with extensive experiments based on five real data sources obtained in Beijing and Shanghai. The results show the advantages of our method over four categories of baselines, including linear/Gaussian interpolations, classical dispersion models, well-known classification models like decision tree and CRF, and ANN.

Co-benefits of mitigating global greenhouse gas emissions for future air quality and human health

Abstract: Actions to reduce greenhouse gas (GHG) emissions often reduce co-emitted air pollutants, bringing co-benefits for air quality and human health. Past studies1-6 typically evaluated near-term and local co-benefits, neglecting the long-range transport of air pollutants7-9, long-term demographic changes, and the influence of climate change on air quality10-12. Here we simulate the co-benefits of global GHG reductions on air quality and human health using a global atmospheric model and consistent future scenarios, via two mechanisms: a) reducing co-emitted air pollutants, and b) slowing climate change and its effect on air quality. We use new relationships between chronic mortality and exposure to fine particulate matter13 and ozone14, global modeling methods15, and new future scenarios16. Relative to a reference scenario, global GHG mitigation avoids 0.5±0.2, 1.3±0.5, and 2.2±0.8 million premature deaths in 2030, 2050, and 2100. Global average marginal co-benefits of avoided mortality are $50-380 (ton CO2)-1, which exceed previous estimates, exceed marginal abatement costs in 2030 and 2050, and are within the low range of costs in 2100. East Asian co-benefits are 10-70 times the marginal cost in 2030. Air quality and health co-benefits, especially as they are mainly local and near-term, provide strong additional motivation for transitioning to a low-carbon future.

Global premature mortality due to anthropogenic outdoor air pollution and the contribution of past climate change

Abstract: Increased concentrations of ozone and fine particulate matter (PM2.5) since preindustrial times reflect increased emissions, but also contributions of past climate change. Here we use modeled concentrations from an ensemble of chemistry?climate models to estimate the global burden of anthropogenic outdoor air pollution on present-day premature human mortality, and the component of that burden attributable to past climate change. Using simulated concentrations for 2000 and 1850 and concentration?response functions (CRFs), we estimate that, at present, 470?000 (95% confidence interval, 140?000 to 900?000) premature respiratory deaths are associated globally and annually with anthropogenic ozone, and 2.1 (1.3 to 3.0) million deaths with anthropogenic PM2.5-related cardiopulmonary diseases (93%) and lung cancer (7%). These estimates are smaller than ones from previous studies because we use modeled 1850 air pollution rather than a counterfactual low concentration, and because of different emissions. Uncertainty in CRFs contributes more to overall uncertainty than the spread of model results. Mortality attributed to the effects of past climate change on air quality is considerably smaller than the global burden: 1500 (?20?000 to 27?000) deaths yr?1 due to ozone and 2200 (?350?000 to 140?000) due to PM2.5. The small multi-model means are coincidental, as there are larger ranges of results for individual models, reflected in the large uncertainties, with some models suggesting that past climate change has reduced air pollution mortality.

Air Pollution Modeling: "Theories, Computational Methods And Available Software"

Abstract: 1 The Problem - Air Pollution.- 2 The Tool - Mathematical Modeling.- 3 Air Pollution Meteorology.- 4 Meteorological Modeling.- 5 Plume Rise.- 6 Eulerian Dispersion Models.- 7 Gaussian Models.- 8 Lagrangian Dispersion Models.- 9 Atmospheric Chemistry.- 10 Dry and Wet Deposition.- 11 Special Applications of Dispersion Models.- 12 Statistical Methods.- 13 Modeling of Adverse Air Quality Effects.- 14 Available Computer Packages.- Index of Authors.- Index of Subject.

Particulate matter beyond mass: recent health evidence on the role of fractions, chemical constituents and sources of emission

Abstract: Particulate matter (PM) is regulated in various parts of the world based on specific size cut offs, often expressed as 10 or 2.5 µm mass median aerodynamic diameter. This pollutant is deemed one of the most dangerous to health and moreover, problems persist with high ambient concentrations. Continuing pressure to re-evaluate ambient air quality standards stems from research that not only has identified effects at low levels of PM but which also has revealed that reductions in certain components, sources and size fractions may best protect public health. Considerable amount of published information have emerged from toxicological research in recent years. Accumulating evidence has identified additional air quality metrics (e.g. black carbon, secondary organic and inorganic aerosols) that may be valuable in evaluating the health risks of, for example, primary combustion particles from traffic emissions, which are not fully taken into account with PM2.5 mass. Most of the evidence accumulated so far i...

Real-time air quality monitoring through mobile sensing in metropolitan areas

Abstract: Traditionally, pollution measurements are performed using expensive equipment at fixed locations or dedicated mobile equipment laboratories. This is a coarse-grained and expensive approach where the pollution measurements are few and far in-between. In this paper, we present a vehicular-based mobile approach for measuring fine-grained air quality in real-time. We propose two cost effective data farming models -- one that can be deployed on public transportation and the second a personal sensing device. We present preliminary prototypes and discuss implementation challenges and early experiments.

Ozone and fine particle in the western Yangtze River Delta: an overview of 1 yr data at the SORPES station

Abstract: . This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e., along the Nanjing–Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.

Assessing the public health impacts of urban air pollution in 25 European cities: Results of the Aphekom project

Abstract: article i nfo Introduction: The Aphekom project aimed to provide new, clear, and meaningful information on the health effects of air pollution in Europe. Among others, it assessed the health and monetary benefits of reducing short and long-term exposure to particulate matter (PM) and ozone in 25 European cities. Method: Health impact assessments were performed using routine health and air quality data, and a common methodology. Two scenarios were considered: a decrease of the air pollutant levels by a fixed amount and a decrease to the World Health Organization (WHO) air quality guidelines. Results were economically valued by using a willingness to pay approach for mortality and a cost of illness approach for morbidity. Results: In the 25 cities, the largest health burden was attributable to the impacts of chronic exposure to PM2.5. Complying with the WHO guideline of 10 μg/m 3

Energy and Environment: Challenges and Achievements in Rapid Urbanization.

Abstract: Nowadays, more than half of the world's population lives in urban areas. It is forecasted that another 20% will move into cities within the next 40 years, most of which will occur in developing countries. It is predicted that the urbanization ratio will increase from the present 52.5% to 70% in 2020 in China. The rapid urbanization questions the sustainability. Cities require huge quantities of energy and materials which produce large quantities of waste products, raising the problems of energy shortage, water pollution, soil pollution, and air quality deterioration. This special issue, of The Scientific World Journal focuses on those problems that we will face during this challenging process. The accepted topics are on the latest research of (1) energy efficient construction and renewable energy use in cities; (2) technologies in waste water treatment; (3) energy saving and pollution control of municipal solid waste incineration; and (4) urban air pollution chemistry, control, and relationship with energy use. Nine papers selected from the submitted nineteen ones are published in this special issue. Some of the papers were unaccepted only because they were beyond the scope of this issue. We would like to express our gratitude to those authors for their support and contributions first in this opening. Out of the nine papers, two were review articles and others were research papers. The topic distributions are two for energy use and saving in cities, three for water pollution control and treatment, one for solid waste treatment, and three for air quality pollution and control. Below is a brief introduction to each of these papers in this special issue. We will introduce the two important review papers at first. The paper “Recent developments of electrochemical promotion of catalysis in the techniques of DeNOX” by X. Tang et al. has summarized many valuable viewpoints related to electrochemical promotion of DeNOX. The removal of NOX is of significant concern in reducing the pollution and protecting the environment at present in China. But up to now, the traditional ways of DeNOX usually need a specific operating temperature window. Because of the situ controllability in the promoter concentration at the surface of a working metal catalyst, the EPOC provides an alternative way to improve catalysts performance. EPOC is quite a recent and remarkable part of catalysis, and hundreds of papers were written on this topic from the pioneering work of C.G. Vayenas in MIT and Patras University. This will be helpful for the development of new catalytic system with low operating temperature and high NOX conversion for the removal of NOX. This paper is valuable for reducing the NOX pollution of industrial exhaust gas and improving environmental quality. The review paper “The hydrolysis of carbonyl sulfide at low temperature: a review” by S. Zhao et al. has systematically summarized the development of catalyst for catalytic hydrolysis of carbonyl sulfide (COS), reaction kinetics, and reaction mechanism and has analyzed some problems which need to be solved in the development of COS removal technology. COS, which widely exists in natural gas, petroleum gas, and water gas, is normally regarded as a significant poison for industrial catalysis. Furthermore, not only does COS lead to economic problems, but also affects the environment. It has been proven to be a major source of acid rain when oxidized to sulfur oxide and to promote photochemical reactions. Some methods have been developed for the removal of COS, including catalyzed hydrogenation, oxidation, and hydrolysis, in which the hydrolysis of COS is recognized as the most promising process due to mild reaction condition, cheapness, and higher conversion efficiency. This paper provides a possible guidance for the development of the organic sulfur removal technology as well as the air pollution control technologies. In Z.-p. Zhang and F.-h. Du's paper “Optimization and thermoeconomics research of a large reclaimed water source heat pump system,” a large reclaimed water source heat pump is introduced as well as its design principles and techniques. Water source heat pump is considered among the most energy efficient technologies for providing heating and cooling in urban constructions. This paper has presented a detailed process of the design of a large, complicated system including a distributed heat pump heating system and a combination of centralized and decentralized systems. It provides an excellent example and reference for the future application of water source heat pump technology. The paper “Flow-field characteristics of high-temperature annular buoyant jets and their development laws influenced by ventilation system” written by Y. Wang et al. has applied a numerical model to understand the flow characteristics of high-temperature annular buoyant jets and the development laws influenced by ventilation system to eliminate the pollutants effectively. Based on the detailed analysis using the appropriate method, the authors have drawn several remarkable conclusions that would be useful to the pollution control in industries. C. Zhu et al.' paper “Reduction of waste water in Erhai lake based on MIKE21 hydrodynamic and water quality model” has applied the MIKE21 hydrodynamic and water quality model in Erhai Lake to simulate the water quality and water environment capacity. Erhai Lake is one of the most famous lakes in China and has suffered a lot from the water pollution in recent years. It may be of particular interest to the policy makers on water quality improvement of Erhai and other similar lakes in China. The paper “Research on phthalic acid esters removal and its health risk evaluation by combined process for secondary effluent of wastewater treatment plant” by S. Li et al. has discussed the treatment efficiency of “coagulation-sedimentation-O3-biological sand filtration-GAC” combined process on phthalic acid esters in secondary effluent of municipal wastewater treatment plant, and the health risk is analyzed as well. It is informative and useful to the in depth treatment of municipal waste water in Chinese cities. In W. Zhang et al.'s paper “Characterization of urban runoff pollution between dissolved and particulate phases,” the characteristics of urban runoff pollution between dissolved and particulate phases are discussed, using 12 rainfall events monitored in five typical urban catchments. It can provide useful information for the future control of the urban runoff pollutions in China. “Formation of humic substances in weathered MSWI bottom ash” is the only paper dealing with solid waste treatment in this special issue. It has presented an evaluation of humic substances content in the bottom ash of municipal solid waste incinerators and its affecting factors such as incubation time and temperature. It has concluded that the high temperature may be beneficial to the formation of humic acid, while low temperatures are conducive to the accumulation of fulvic acid. Two extraction reagents are compared as well, and the optimal formula is recommended. The paper “Quantifying the sources of the severe haze over the southern Hebei using the CMAQ model” has applied the MM5-Models-3/CMAQ modeling system to quantify the source contributions to the PM2.5 concentrations in the southern Hebei cities, Shijiazhuang and Xingtai, which may be the top one and two polluted cities in China. This paper has examined the importance of each sector to the air pollution in these two cities. It may be of particular interest to the policy makers in the future air pollution control in this area.

The 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study

Abstract: The California Research at the Nexus of Air Quality and Climate Change (CalNex) field study was conducted throughout California in May, June, and July of 2010. The study was organized to address issues simultaneously relevant to atmospheric pollution and climate change, including (1) emission inventory assessment, (2) atmospheric transport and dispersion, (3) atmospheric chemical processing, and (4) cloud-aerosol interactions and aerosol radiative effects. Measurements from networks of ground sites, a research ship, tall towers, balloon-borne ozonesondes, multiple aircraft, and satellites provided in situ and remotely sensed data on trace pollutant and greenhouse gas concentrations, aerosol chemical composition and microphysical properties, cloud microphysics, and meteorological parameters. This overview report provides operational information for the variety of sites, platforms, and measurements, their joint deployment strategy, and summarizes findings that have resulted from the collaborative analyses of the CalNex field study. Climate-relevant findings from CalNex include that leakage from natural gas infrastructure may account for the excess of observed methane over emission estimates in Los Angeles. Air-quality relevant findings include the following: mobile fleet VOC significantly declines, and NO_x emissions continue to have an impact on ozone in the Los Angeles basin; the relative contributions of diesel and gasoline emission to secondary organic aerosol are not fully understood; and nighttime NO_3 chemistry contributes significantly to secondary organic aerosol mass in the San Joaquin Valley. Findings simultaneously relevant to climate and air quality include the following: marine vessel emissions changes due to fuel sulfur and speed controls result in a net warming effect but have substantial positive impacts on local air quality.

Formaldehyde in the Ambient Atmosphere: From an Indoor Pollutant to an Outdoor Pollutant?

Abstract: Formaldehyde has been discussed as a typical indoor pollutant for decades. Legal requirements and ever-lower limits for formaldehyde in indoor air have led to a continual reduction in the amount of formaldehyde released from furniture, building materials, and household products over many years. Slowly, and without much attention from research on indoor air, a change of paradigm is taking place, however. Today, the formaldehyde concentrations in outdoor air, particularly in polluted urban areas, sometimes already reach indoor levels. This is largely a result of photochemical processes and the use of biofuels. In the medium term, this development might have consequences for the way buildings are ventilated and lead to a change in the way we evaluate human exposure.

Evaluation of dust and trace metal estimates from the Community Multiscale Air Quality (CMAQ) model version 5.0

Abstract: . The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transformation, transport, and fate of the many different air pollutant species that comprise particulate matter (PM), including dust (or soil). The CMAQ model version 5.0 (CMAQv5.0) has several enhancements over the previous version of the model for estimating the emission and transport of dust, including the ability to track the specific elemental constituents of dust and have the model-derived concentrations of those elements participate in chemistry. The latest version of the model also includes a parameterization to estimate emissions of dust due to wind action. The CMAQv5.0 modeling system was used to simulate the entire year 2006 for the continental United States, and the model estimates were evaluated against daily surface-based measurements from several air quality networks. The CMAQ modeling system overall did well replicating the observed soil concentrations in the western United States (mean bias generally around ±0.5 μg m−3); however, the model consistently overestimated the observed soil concentrations in the eastern United States (mean bias generally between 0.5–1.5 μg m−3), regardless of season. The performance of the individual trace metals was highly dependent on the network, species, and season, with relatively small biases for Fe, Al, Si, and Ti throughout the year at the Interagency Monitoring of Protected Visual Environments (IMPROVE) sites, while Ca, K, and Mn were overestimated and Mg underestimated. For the urban Chemical Speciation Network (CSN) sites, Fe, Mg, and Mn, while overestimated, had comparatively better performance throughout the year than the other trace metals, which were consistently overestimated, including very large overestimations of Al (380%), Ti (370%) and Si (470%) in the fall. An underestimation of nighttime mixing in the urban areas appears to contribute to the overestimation of trace metals. Removing the anthropogenic fugitive dust (AFD) emissions and the effects of wind-blown dust (WBD) lowered the model soil concentrations. However, even with both AFD emissions and WBD effects removed, soil concentrations were still often overestimated, suggesting that there are other sources of errors in the modeling system that contribute to the overestimation of soil components. Efforts are underway to improve both the nighttime mixing in urban areas and the spatial and temporal distribution of dust-related emission sources in the emissions inventory.

Indoor air quality and sources in schools and related health effects.

Abstract: Good indoor air quality in schools is important to provide a safe, healthy, productive, and comfortable environment for students, teachers, and other school staff. However, existing studies demonstrated that various air pollutants are found in classrooms, sometimes at elevated concentrations. Data also indicated that poor air quality may impact children's health, in particular respiratory health, attendance, and academic performance. Nevertheless, it should be noted that there are other adverse health effects that are less documented. Few data exist for teachers and other adults that work in schools. Allergic individuals seem to be at a higher risk for adverse respiratory health consequences. Air quality improvement represents an important measure for prevention of adverse health consequences in children and adults in schools.

Five years of London’s low emission zone: Effects on vehicle fleet composition and air quality

Abstract: This paper uses registration and enforcement information to assess the impact of London’s low emission zone on vehicle registrations, usage and air pollution. The zone was implemented in a staged process in 2008 to reduce the emissions of air pollutants of direct harm to human health. The zone targeted the worst polluters, specifically heavy diesel vehicles, buses and coaches by imposing minimum emissions standards on vehicles operating in an area covering most of Greater London. Several years on it remains unclear how successful the zone has been in meeting its stated objectives and what improvements in pollution levels can be attributed to the low emission zone. Results presented in this paper suggest the rate of fleet turnover for affected vehicle classes in London increased substantially when the zone was first introduced before returning to the national average in subsequent years. Early evidence for light commercial vehicles, which became subject to the scheme in early 2012, shows a similar effect is likely. Despite an overall growth in freight vehicles operating in London, the number of pre-Euro III vehicles has dropped and this has been coupled with a switch from rigid vehicles to light commercial vehicles and articulated vehicles. Ambient air quality measurements show concentrations of particulate matter within the low emission zone have dropped by 2.46–3.07% compared to just over 1% for areas just outside the zone. However, no discernible differences are found for NOX concentrations.

Do ‘green’ buildings have better indoor environments? New evidence

Abstract: A post-occupancy evaluation (POE) of 12 green and 12 conventional office buildings across Canada and the northern United States was conducted. Occupants (N = 2545) completed an online questionnaire related to environmental satisfaction, job satisfaction and organizational commitment, health and well-being, environmental attitudes, and commuting. In each building on-site physical measurements at a sample of workstations (N= 974) were taken, including: thermal conditions, air quality, acoustics, lighting, workstation size, ceiling height, window access and shading, and surface finishes. Green buildings exhibited superior performance compared with similar conventional buildings. Better outcomes included: environmental satisfaction, satisfaction with thermal conditions, satisfaction with the view to the outside, aesthetic appearance, less disturbance from heating, ventilation and air-conditioning (HVAC) noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne p...

Short-Term Exposure to Air Pollution and Lung Function in the Framingham Heart Study

Abstract: Rationale: Short-term exposure to ambient air pollution has been associated with lower lung function. Few studies have examined whether these associations are detectable at relatively low levels of pollution within current U.S. Environmental Protection Agency (EPA) standards.Objectives: To examine exposure to ambient air pollutants within EPA standards and lung function in a large cohort study.Methods: We included 3,262 participants of the Framingham Offspring and Third Generation cohorts living within 40 km of the Harvard Supersite monitor in Boston, Massachusetts (5,358 examinations, 1995–2011) who were not current smokers, with previous-day pollutant levels in compliance with EPA standards. We compared lung function (FEV1 and FVC) after previous-day exposure to particulate matter less than 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in the “moderate” range of the EPA Air Quality Index to exposure in the “good” range. We also examined linear relationships between moving averages o...

Characterization and assessment of volatile organic compounds (VOCs) emissions from typical industries

Abstract: VOCs play an increasingly important role in affecting air quality and threatening human health in China in recent years, where industry activities show a significant contribution to VOCs emission. In this article we report our long term study of industrial VOCs emissions of six major industries (vehicle manufacturing, printing, equipment coating, electronic manufacturing, furniture manufacturing and bio-pharming) on the aspects of emission characteristics, environmental impact and health risk assessment, and control challenge analysis with the purpose to obtain in-depth understanding of industry VOCs emissions and offer some original basements for national control and management of industry VOCs emissions. This study shows that all these industries give middle or low emission with total VOCs concentration less than 1000 mg/m3 at each exhaust pipe. Benzenes, esters, alcohols, ketones, alkanes, chloroalkanes and alkenes were detected as the major emission components and the most frequently monitored VOCs were benzenes, which varied obviously with different processes and industries. The environmental impact assessments indicate that vehicle manufacturing and benzenes should be prior controlled with the purpose to reduce air pollution. While, health risk assessments suggest that furniture manufacturing and chloroalkanes should be firstly controlled. Control analysis indicates that developing technologies with low cost and high efficiency and establishing and completing specific industry emission standards/regulations are the two key issues in VOCs emission management at present stage.