Outcomes of the first round of local authority air quality Review and Assessments under the UK's air quality strategy

In 1997, the UK government instigated the practice of Local Air Quality Management (LAQM) in the UK. This process is based on local authorities undertaking Review and Assessments of air quality within their areas. The first round of Review and Assessments have now been completed and represents the most extensive and coordinated analysis of air pollution ever undertaken in the UK, and probably in Europe. This paper takes a broad look at the outcomes of this process so far and identifies some of the key areas where lessons have/can be learnt both about patterns of air pollution in the UK and about the framework for investigating these that has been implemented under the LAQM regime. The process has led to a much higher number of local authorities finding problems with air pollution than initially expected. It has also challenged many assumptions about the significance of various pollutants and their sources.     

Treatment of Urban Areas within a Regional Transport Model of Sulphur and Nitrogen Oxides

The air pollution transport model UGEM (The University of Greenwich Evaluation Model) has been developed to evaluate medium-range transport and deposition of sulphur and oxidised nitrogen from all types of sources of emissions in the UK and to estimate their average annual deposition and concentrations across the UK. The model has been tested for its predictions against the available measurements.This study was focused on a possibility of applying the UGEM model to the assessment of air quality on a local scale. One parameter in the model is crucial, the local deposition fraction. The effect of this parameter on quality of the model predictions has been studied for different scales of UGEM output, such as the whole territory of the UK, a rural region and an urban area.The results of the study show that the magnitude of the local deposition fraction should be different for each grid square to reach the best agreement of predictions of concentrations with measurements. Applying a local value of the parameter to each grid square will improve the model predictions of the concentrations in urban areas in particular and will not affect the quality of model predictions of the wet deposition.     

Pollution prevention at ports: clearing the air

Seaports are major hubs of economic activity and of environmental pollution in coastal urban areas. Due to increasing global trade, transport of goods through ports has been steadily increasing and will likely continue to increase in the future. Evaluating air pollution impacts of ports requires consideration of numerous sources, including marine vessels, trucks, locomotives, and off-road equipment used for moving cargo. The air quality impacts of ports are significant, with particularly large emissions of diesel exhaust, particulate matter, and nitrogen oxides. The health effects of these air pollutants to residents of local communities include asthma, other respiratory diseases, cardiovascular disease, lung cancer, and premature mortality. In children, there are links with asthma, bronchitis, missed school days, and emergency room visits. The significance of these environmental health impacts requires aggressive efforts to mitigate the problem. Approaches to mitigation encompass a range of possibilities from currently available, low-cost approaches, to more significant investments for cleaner air. Examples of the former include restrictions on truck idling and the use of low-sulfur diesel fuel; the latter includes shore-side power for docked ships, and alternative fuels. A precautionary approach to port-related air pollution would encourage local production of goods in order to reduce marine traffic, greener design for new terminals, and state-of-the art approaches to emissions-control that have been successfully demonstrated at ports throughout the world.     

Air-quality modelling in the Lake Baikal region

In this paper, we assess the status of the air quality in the Lake Baikal region which is strongly influenced by the presence of anthropogenic pollution sources. We combined the local data, with global databases, remote sensing imagery and modelling tools. This approach allows to inventorise the air-polluting sources and to quantify the air-quality concentration levels in the Lake Baikal region to a reasonable level, despite the fact that local data are scarcely available. In the simulations, we focus on the month of July 2003, as for this period, validation data are available for a number of ground-based measurement stations within the Lake Baikal region.     

Air quality assessment of Estarreja, an urban industrialized area, in a coastal region of Portugal

Despite the increasing concern given to air quality in urban and industrial areas in recent years, particular emphasis on regulation, control, and reduction of air pollutant emissions is still necessary to fully characterize the chain emissions–air quality–exposure–dose–health effects, for specific sources. The Estarreja region was selected as a case study because it has one of the largest chemical industrial complexes in Portugal that has been recently expanded, together with a growing urban area with an interesting location in the Portuguese coastland and crossed by important road traffic and rail national networks. This work presents the first air quality assessment for the region concerning pollutant emissions and meteorological and air quality monitoring data analysis, over the period 2000–2009. This assessment also includes a detailed investigation and characterization of past air pollution episodes for the most problematic pollutants: ozone and PM10. The contribution of different emission sources and meteorological conditions to these episodes is investigated. The stagnant meteorological conditions associated with local emissions, namely industrial activity and road traffic, are the major contributors to the air quality degradation over the study region. A set of measures to improve air quality—regarding ozone and PM10 levels—is proposed as an air quality management strategy for the study region.     

Air quality assessment of benzo(a)pyrene from asphalt plant operation

A study has been carried out to assess the contribution of Polycyclic Aromatic Hydrocarbons (PAHs) from asphalt plant operation, utilising Benzo(a)pyrene (BaP) as a marker for PAHs, to the background air concentration around asphalt plants in the UK. The purpose behind this assessment was to determine whether the use of published BaP emission factors based on the US Environmental Protection Agency (EPA) methodology is appropriate in the context of the UK, especially as the EPA methodology does not give BaP emission factors for all activities. The study also aimed to improve the overall understanding of BaP emissions from asphalt plants in the UK, and determine whether site location and operation is likely to influence the contribution of PAHs to ambient air quality. In order to establish whether the use of US EPA emissions factors is appropriate, the study has compared the BaP emissions measured and calculated emissions rates from two UK sites with those estimated using US EPA emission factors. A dispersion modelling exercise was carried out to show the BaP contribution to ambient air around each site. This study showed that, as the US EPA methodology does not provide factors for all emission sources on asphalt plants, their use may give rise to over- or under-estimations, particularly where sources of BaP are temperature dependent. However, the contribution of both the estimated and measured BaP concentrations to environmental concentration were low, averaging about 0.05 ng m(-3) at the boundary of the sites, which is well below the UK BaP assessment threshold of 0.25 ng m(-3). Therefore, BaP concentrations, and hence PAH concentrations, from similar asphalt plant operations are unlikely to contribute negatively to ambient air quality.     

Emission inventory of evaporative emissions of VOCs in four metro cities in India

High concentrations of volatile organic compounds (VOCs) in ambient air of urban areas stress the need for the control of VOC emissions due to the toxic and carcinogenic nature of many VOCs commonly encountered in urban air. Emission inventories are an essential tool in the management of local air quality, which provide a listing of sources of air pollutant emissions within a specific area over a specified period of time. This study intended to provide a level IV emission inventory as par the United States Environmental Protection Agency (USEPA) definition for evaporative VOC emissions in the metro cities of India namely Delhi, Mumbai, Chennai, and Kolkata. The vehicular evaporative emissions are found to be the largest contributor to the total evaporative emissions of hydrocarbons followed by evaporative losses related to petrol loading and unloading activities. Besides vehicle-related activities, other major sources contributing to evaporative emissions of hydrocarbons are surface coating, dry cleaning, graphical art applications, printing (newspaper and computer), and the use of consumer products. Various specific preventive measures are also recommended for reducing the emissions.     

Relating Background NO2 Concentrations in Air to Air Mass History Using Non-Parametric Regression Methods: Application at Two Background Sites in Ireland

The concentration of nitrogen dioxide (NO₂) in background air varies temporally and spatially and is influenced by meteorological and anthropogenic factors. Background concentrations used in local air quality modelling studies have a significant effect on the accuracy of the overall result and when based on short-term monitoring data, variation in concentrations with air mass history is often unaccounted for. The current paper presents a powerful tool for the quantification and separation of local and regional air mass effects on background air quality. The origin of and the regions traversed by an air mass prior to reaching a receptor has been modelled using HYsplit-4. Trajectories (between 12 and 96?h duration) were defined based on the frequency with which they passed into 16 predefined compass quadrants and each represented as a vector. Using this vector as the predictor variable and the background concentration as the response variable, non-parametric regression using a Gaussian kernel function was carried out. A graphical output indicated the trajectory direction of maximum NO₂ concentration, while allowing distinction to be made between spurious and true peaks. In all cases, air mass history was found to have a statistically significant effect on NO₂ concentrations. Incorporating emissions data into the analysis local and regional effects were separated and quantified. It was found that emissions in the UK and Europe have a significant effect on background NO₂ concentrations in Ireland and in some instances supersede domestic emissions. The methods can be used to identify source regions, separate local and regional effects and improve predictions of background concentrations based on limited monitoring data. In particular, the results highlight the importance of considering air mass history when assessing background concentration levels for use in local air quality modelling studies.     

Waste management modeling by MARKAL model: A case study for Basilicata Region

Air pollution is one of the most pressing environmental problems which affects likewise urban, industrial and rural areas. Environmental planners, regulators and decision makers need reliable, scientifically based tools to find out strategies for controlling air pollution in a cost-effective way, taking into account the whole productive system. In this framework the basic elements of energy-environmental planning have to be extended to include also waste processing technologies amongst the usually considered pollution sources. Bottom-up optimizing models, based on linear programming techniques and customized for specific cases, represent a powerful tool in energy-environmental management. This paper focuses on the integrated modeling of material flows and energy system performed on a local scale case study (Basilicata Region, Southern Italy) using the linear programming model IEA-MARKAL. We have evaluated the feasibility of the model in representing the waste management system to estimate the environmental impact of the waste processing technologies in the context of the whole productive system. A sensitivity analysis has been carried out to emphasize the connections between tariffs, waste disposal technologies assessment and atmospheric emissions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Long-Term Air Quality Assessment: Modeling Sources Contribution and Scenarios In Ivrea And Torino Areas

An evaluation of the air quality based on the combined use of monitoring data, dynamic emission inventories, and three-dimensional modeling has been performed in an area in North West Italy. Yearly maps of the pollutants of most concern have been produced by means of an Eulerian modeling system, run for two nested domains. The system is based on MINERVE diagnostic meteorological model, TREFIC (TRaffic Emission Factors Improved Calculation) traffic emission module, and farm air quality regional chemical-transport model. The zooming approach has allowed to correctly reproduce local concentrations in the small urban area in the inner domain as well as to quantify the role played by selected local sources respect to distant ones. The study of the impact of the future car fleet, pointing out the expected improvement for nitrogen oxides and the persisting problem of PM, provides a rationale for air quality governance.     

Air quality impact assessment

Air quality impact assessment (AQIA) is an important technique for determining the relative contribution to ground level pollutant concentrations of specific current or future source emissions at receptor sites. The principal activities in AQIA are air quality modelling and monitoring techniques. The choice of techniques which are applicable to a particular situation is intimately related to the problem to be assessed. A review of relevant modelling techniques has been presented, with emphasis placed on Gaussian plume models because of their ease of use and broad applicability. Alternative modelling techniques have been suggested when departures from the Gaussian form in the atmosphere occurs or when more detailed information on atmospheric chemistry, deposition or long range transport is required. The objectives and techniques of ambient air quality monitoring have been examined and the siting of instruments, duration and frequency of sampling, choice of monitoring rationale (fixed or mobile), minimization of sampling errors, data storage and analysis are discussed. Modelling and monitoring are essential to successful AQIA. An orderly approach to the principles and procedures involved in performing AQIA studies, using these two techniques in conjunction, has been presented.     

长三角城市群污染输送相互影响的敏感性试验

利用WRF-Chem模式,对2013年11月29日至12月11日长江三角洲地区的严重空气污染事件进行数值模拟,研究长三角核心区不同污染物本地源和外来输送所占比重。分析长三角核心区排放源对本地不同污染物浓度的污染贡献。结果表明,在2013年12月的这一次污染事件中,颗粒物平均本地贡献与外来输送基本比重相当;而SO_2、CO、NH_3、NO_x这4种气体污染物则以本地贡献为主,本地贡献的差异与气体的化学反应活性有关,活性越强本地贡献比重越大。污染过程中12月7日至12月9日00:00为污染最严重的时段,污染物的本地贡献有明显上升。区域间输送的方向和强度与地面风向、风速有紧密的联系。在边界层高度范围内,大部分污染物越往高空本地排放源的贡献越弱,外来输送主导作用增强,而硝酸盐在地面、1 km和1.5 km的本地贡献差异远小于其他污染物。     

Estimation of the Thermal Sensitivity of a Dwelling to Variations in Architectural and Behavioural Parameters

The provision of energy for households is a major contributor to greenhouse gas emissions in the domestic sector. There is significant scope for energy savings and thus emission reduction in this sector. This paper constructs a bridge between thermal analysis and environmental assessment in the occupancy stage of the dwelling life cycle, approaching both methods as being on a common system Environment–Dwelling–Inhabitant. The importance of the local level in the thermal analysis and assessment of either a dwelling or an inhabitant's behaviour is demonstrated. It is shown that the researcher can choose between natural experiment, computer experiment and mathematical modelling to analyze the system. Such a choice is discussed for two particular methods of thermal analysis. Thermal Nomograms are the result of mathematical modelling, and the Energy Score Sheet is the result of a computer experiment in energy rating. Despite being developed for the purpose of thermal analysis, these methods can also be utilized for environmental assessment at the local level. The discussion centres on Australian conditions where the majority of the population resides in a relatively benign climate wherein behavioural alterations have significant potential for energy savings and environmental impact. The purpose of the paper is to emphasise benefits apart from energy minimisation to promote the use of energy efficient housing strategies.     

A GIS-based Study for Optimizing the Total Emission Control Strategy in Lanzhou City

A geographic information system (GIS)-based approach with spatial analysis advantages was developed to optimize the total emission control scheme on air pollution in Lanzhou, combined with Models-3 modeling system and a linear programming model. GIS system is mainly used for establishing a multifactor assessment model to quantitatively divide environmental functional zone, and also used for selecting control sites in linear programming model. The results show that most of the urban area belongs to the second type of function, which is 122.8 km² occupying about 76.5% and the third type of about 32.9 km² occupying 20.5%. To reach the air quality up to the national standard in the entire control area, some large-emission factories need to cut emissions from 19% to 27%. For small but low-emission height sources, the cut may be as high 40%. The improvement of the ecological environment is urgently needed for controlling the background particle pollution in Lanzhou city.     

A dynamic analysis of the global warming potential associated with air conditioning at a city scale: an empirical study in Shenzhen,China

Heating, ventilation and air conditioning (HVAC) systems are a major source of energy consumption in buildings, directly and indirectly contributing to greenhouse gas (GHG) emissions. In the urban environment, and depending on local climatic conditions, air conditioning units attribute to these high energy demands. This study analyzes the use of residential air conditioning units and their associated global warming potential (GWP) between 2005 and 2030 for the city of Shenzhen, a fast-growing megacity located in Southern China. A life cycle assessment approach was adopted to quantify the GWP impacts which arise from both direct (refrigerant release) and indirect (energy consumption) sources, in combination with a materials flow analysis approach. The results show that the total GWP (expressed as carbon dioxide equivalents, CO₂ eq.) from residential air conditioning systems increased from 2.2 ± 0.2 to 5.1 ± 0.4 million tonnes (Mt) CO₂ eq. between 2005 and 2017, with energy consumption and refrigerant release contributing to 72.5% and 27.5% of the total demands, respectively. Immediate measures are required to restrict refrigerant release and reduce the energy consumption of air conditioning units, to help mitigate the predicted additional total emissions of 36.4 Mt. CO₂ eq. potentially released between 2018 and 2030. This amount equals to approximately New Zealand's national CO₂ emissions in 2017. The findings proposed in this study targets air conditioning units to reduce the GWP emissions in cities, and provide useful data references and insights for local authorities to incentivise measures for improving building energy efficiency management and performance.     

Verifying emission factors and national POPs emission inventories for the UK using measurements and modelling at two rural locations

Different approaches are used to verify the adequacy of emission factors (EFs) and their use in emission inventories of persistent organic pollutants (POPs). The applicability of EFs was tested using atmospheric dispersion modelling to predict atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and resulting toxic equivalents (SigmaTEQ) and particulate matter <10 microm (PM(10)) in two rural locations in northern England (UK). The modelling was based on general assumptions of fuel composition, consumption and heating needs to simulate emissions of POPs from the domestic burning of coal and wood where ambient measurements were made in the winter of 1998. The model was used to derive the local contribution to ambient air concentrations, which were estimated independently based on comparative air measurements. The results support the hypothesis that in both villages, the majority of PAHs and the lower chlorinated PCDFs were locally released. The situation for PCBs and polychlorinated naphthalenes (PCNs) was different. While the EFs show the release of both compound groups from the domestic burning of coal and wood, the ambient levels of these "legacy POPs" in the villages were still clearly dominated by other sources. Rural areas relying mainly on fossil fuels can exceed the proposed UK ambient air quality standard for benzo[a]pyrene during winter. The measured EFs were then used to estimate the importance of the domestic burning of coal and wood to national emission inventories for these compound classes. Extrapolations to the UK suggest that the domestic burning of pure wood and coal were minor emitters for chlorinated POPs but contributed strongly to PAH and PM(10) levels in 2000. Finally, the UK's national POPs emission inventories based on source inventories and EF, as used here, were compared to estimates derived using the increase in atmospheric concentration of selected POPs.     

Differences in the Spatial Distribution and Chemical Composition of PM10 Between the UK and Poland

The Fine Resolution Atmospheric Multi-pollutant Exchange Model was used to calculate the spatial distribution and chemical composition of PM₁₀ concentrations for two geographically remote countries in Europe—the UK and Poland—for the year 2007. These countries are diverse in terms of pollutant emissions as well as climate conditions. Information on the contribution of natural and anthropogenic as well as national and imported particles in total PM₁₀ concentrations in both countries is presented. The paper shows that the modelled national annual average PM₁₀ concentrations, calculated for the entire country area, are similar for the UK and Poland and close to 12 μg m^?3. Secondary inorganic aerosols dominate the total PM₁₀ concentrations in Poland. Primary particulate matter has the greatest contribution to total PM₁₀ in the UK, with large contribution of base cations. Anthropogenic sources predominate (81 %) in total PM₁₀ concentrations in Poland, whereas natural prevail in the UK—hence, the future reduction of PM₁₀ air concentrations by emissions reduction could be more difficult in the UK than in Poland.     

Why Use One Model? An Approach for Encompassing Model Uncertainty and Improving Best Practice

There has been some discussion within the UK modelling community regarding the preferred choice of dispersion model for assessing the air quality impact of elevated point sources, each of which is reported to perform better than the other in certain circumstances. Coupled to this is the growing acceptance within the modelling community to include some recognition of model uncertainty in its reporting. As computer processing speeds increase further, this paper considers the possibility of using more than one model and highlights some of the advantages in doing so.     

Assessment of the Health Impacts of Particulates from the Redevelopment of Kings Cross

The Kings Cross/St. Pancras area has been a rail transport hub from Central London to the Midlands and North Eastern England since the middle of the nineteenth century and dust from the Kings Cross railway lands was even described by Charles Dickens.¹ The Channel Tunnel high speed Rail Link (CTRL) is being constructed between 2001 and 2007 to connect continental Europe to Central London. The CTRL and associated development will help regenerate an area that is surrounded by deprived high density housing estates. London Borough of Camden has set up an extensive particulate monitoring programme to determine if there are any health impacts on local residents from emissions from the demolition and construction work. This article assesses the results from particulate measurements in 2003–2004 and compares this to baseline conditions before the redevelopment work began. The evidence suggests that although 2003 had higher than average pollution levels in the UK as a whole, even higher levels of particulates in the size range PM₁₀–PM_2.5 (defined as PM_coarse) were measured in Kings Cross. Due to the size of these particulates, they tend to be released from construction works rather than transport or secondary particulate sources. Concentrations in 2004 were lower than 2003, but this was primarily due to meteorological conditions. The paper also looks at the health of the local population and discusses whether these elevated levels are creating a problem and legally constitute a statutory nuisance. The Council continues to work with the contractors to try and ensure best practical means to minimise dust emissions and their effect on local residents. ¹Our Mutual Friend