Air Pollution Modelling

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AIR POLLUTION MODELLING  A REVIEW

AIR POLLUTION MODELLING A REVIEW

Effective air pollution control is extremely challenging to both researcher and administrators around the world, due to heterogeneous and dynamic nature of natural environment. To reduce the impact of air pollution and improve the air quality, constant efforts are required 1) to build extensive inventories of pollutant emissions, 2) to determine the source, substance and dispersion rates of these emissions, 3) to develop computer-based numerical models based on mass conservation flows, 4) to assess the levels of concentration and exposure to air pollution at every location over a particular urban area (Liu et al., 2007). Thus, in order to form various air pollution control policies and strategies, air pollution modelling plays an important role. Air pollution dispersion models are used to effectively and efficiently plan the management (environment management plan) of air pollution on particular area/ road corridor, along with monitoring of air pollutants. They not only aid in determining the presently influenced area but also help in identifying the future scenarios under different emission/source and meteorological conditions made by these models.
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Air pollution modelling over complex topography

Air pollution modelling over complex topography

Monti and Leuzzi (1996) point out that suitable parametrization for vertical skewed tur- bulence are necessary for air pollution modelling over complex terrain. Skewed turbulence structure has been therefore included in the lagrangian model developed in present work (chapter 3), in order to account for modification in dispersion processes induced by the presence of orographic obstacles, mainly occurring due to differential heating, as explained in chapter 2. In fact, during daytime atmospheric turbulence within the atmospheric boundary layer originates both from heating of the land surface and from the presence of wind shear; this fact is much more evident when the local approach for the heat bal- ance discussed in section 2.2 is adopted. This leads to the formation of random up-draft and down-draft thermals called eddies. Up-drafts have higher velocities but occupy less area than down-drafts, leading to a skewed vertical velocity distribution (Luhar and Bitter, 1989; Luhar et al., 1996). Transport of pollutants in the atmosphere is dominated horizont- ally by the mean wind and vertically by turbulence. Hence, when modelling atmospheric dispersion, one often assumes homogeneous turbulence in the horizontal directions, but inhomogeneous in the vertical (depending on height). The details of the transport within the ABL are not so important since the temporal scale of vertical mixing is much shorter than the transport times.
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Implementation of multirate time integration methods for air pollution modelling

Implementation of multirate time integration methods for air pollution modelling

A further defect concerns the parallelization speedup: while the problem scales well for up to eight processors, em- ploying sixteen processors yields only very little improve- ment. At least in part this results from inhomogeneities due to the distribution of the point sources. The strongest point sources are inhomogeneously distributed on the blocks with the highest temporal and spatial refinement level. Each of the point sources induces significantly increased cost for the chemistry solver. For up to eight processors the blocks con- taining the point sources are distributed evenly on all proces- sors; for more processors this is not the case. This problem is even more complicated due to the temporally varying wind field. Due to higher concentrations the speed of chemical re- actions inside of the plume is significantly higher than in free air. If the plume is transported into a previously empty cell, computational cost of this cell is increased for the next time step. This effect can not easily be taken into consideration a priori. However employing dynamic repartitioning based on the measured workload per block seems to be a promising way to tackle this problem.
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A Comparitive Study on Air Pollution Modelling Techniques – A Review

A Comparitive Study on Air Pollution Modelling Techniques – A Review

Air-contamination models are generally utilized by national and local authorities to evaluate consistence with air-quality point of confinement esteems (ex-post), just as to measure the effect of conceivable future improvements (e.g., for regulatory purposes for ex-ante ecological effect appraisals). In this specific situation, models are connected to supplement existing estimations or to evaluate focuses or testimonies in territories where no observing destinations exist (for this situation, progressively complex models can give increasingly precise portrayals of complex fixation or testimony fields than interpolation procedures)Figures 1and 2 provide examples of the analysis of air pollution using atmospheric chemistry transport models and serve to illustrate the abundance of applications of air-pollution models at different scales and for different purposes
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Air pollution modelling for birth cohorts: a time-space regression model

Air pollution modelling for birth cohorts: a time-space regression model

In birth cohort studies, models designed to accurately estimate individual traffic-related air pollution exposure for different biologically relevant time windows (i.e., dur- ing and after pregnancy) are therefore of extreme im- portance. A few birth cohorts have used dispersion models to estimate hourly or daily air pollution levels, and subsequently calculated exposure during pregnancy [13, 17, 18]. These models are very demanding in terms of data requirements and processing time, especially when the temporal and spatial resolution has to capture variation by season and within a few hundred meters. The easiest and most cost-effective way to estimate air pollution with the finest temporal resolution is to use data from fixed air quality monitoring (AQM) stations [19] with the disadvantage of having coarse spatial coverage. Inverse distance weighting and kriging may be used to model the spatial variability, though, depending on density of the monitors, complexity of topography, urbanization and meteorological conditions, these methods are often not sufficient to capture contrasts in exposures [19]. On the other hand, land use regression (LUR) models have been increasingly used to estimate long term exposure in cohort studies [20, 21]. In general LUR models focus on spatial variability over longer averaging periods, disregarding fine scale temporal variability, al- though attempts have been made to apply post-hoc tem- poral adjustments to LUR estimates by means of fixed air quality monitoring stations for birth cohort studies [15, 22 – 27]. However, this solution assumes no spatial changes in exposure patterns in time, which may not be applicable in some regions.
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Three-dimensional geospatial compact abstract cell complexes data structure for urban air pollution modelling

Three-dimensional geospatial compact abstract cell complexes data structure for urban air pollution modelling

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Ambient Air Pollution Modelling in Puducherry, India

Ambient Air Pollution Modelling in Puducherry, India

Modeling of air pollution has been accomplished with the aid of Gaussian Dispersion Plume models that accounted for the temporal and spatial dispersion characteristics of the pollutants. Vehicular emission is generally considered as a line source in air dispersion models. Line source models are used for assessing the effects of roadway emissions (Nagendra and Khare, 2002 and Venkatraman and Horst, 2005). They are computer-based models that calculate the distribution of the pollutants in the atmosphere from specified emission sources and meteorological scenario. The present research paper, thus, evaluates the application of CALINE 4 in predicting the concentrations of Carbon-mono-oxide (CO) in the study area.CALINE4, the latest in CALINE series models, is most widely used. Gaussian based vehicular pollution dispersion model to predict air pollutant concentrations along the highway under rural (i.e. Open), semi urban and urban conditions with and without street canyon effects. CALINE series of models have been used extensively all over the world, including India for regulatory purposes. CALINE4 offers several advantages over the other previous models and has been used by many researchers to predict pollutant concentrations of vehicular pollutants along the roads/ highways in Indian climatic conditions. (Nirjar et al., 2002) had used CALINE4 to predict the concentrations of CO along the urban and semi-urban roads in Delhi and the study results showed under prediction and moderate r2 correlation values between observed and predicted concentrations. Further, (Gramotnev et al., 2013) used CALINE4 for the analysis aerosols of (fine and ultra-fine particles) generated by vehicles on a busy road and found good agreement between observed and predicted concentrations. (Sharma et al., 2007) used the CALINE4 model in an urban highway corridor in Delhi. The study concluded that model performed satisfactorily in vehicle exhaust contributes in air quality. (Dhyani et al., 2005) evaluated and compared the performance of CALINE4 model for hilly and flat terrain. They observed unsatisfactory performance of the model in hilly regions due to complex topography and micro meteorological conditions which could not be properly simulated in CALINE4. The present paper, briefly discusses parameters influencing the vehicular pollution dispersion beside evaluation of CALINE4 model performance along an urban highway corridor in Delhi as a case study.
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Air Pollution in the Gulf of Mexico

Air Pollution in the Gulf of Mexico

operating. VOC’s show a strange behavior, while Ciudad del Carmen has the first place (>18,000 KTon∙yr −1 ), Champoton has the second place which is odd, because there is any industry. Regarding this, Cerón et al. [19] reported formaldehyde and acetaldehyde concentrations in air ambient higher than those reported for other au- thors in Mexico and other sites around the world. In addition, the results obtained during this study indicate that BTEX levels in Carmen City are comparable with those found in big polluted cities. However, it is necessary to assess the source-receptor relation by using models to estimate the contribution of regional and local emissions to the total levels of VOC’s in this site.
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Air Pollution in Delhi: An Analysis

Air Pollution in Delhi: An Analysis

dangerous and extra quantity of substances which includes gases, particulate matter, and biological molecules are inserted into atmosphere of Earth. This can cause complex and severe diseases to humans; it may also cause harm and damage to other living organisms and food crops, and may destroy the natural and built ecology and environment. Human activities and natural processes both can generate air pollution to a great extent. Unfortunately, India is among those countries with maximum number of most polluted cities in the world with one of the worst Air Quality Index (AQI) especially, on the festival of Diwali; the air quality index of Delhi and NCR has reached to a new higher levels . Lately, the air pollution in Delhi and NCR has gone through many changes in terms of the level of pollutants and the control measures taken to control it.
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Ambient air pollution and thrombosis

Ambient air pollution and thrombosis

The study by Kilinç et al. (2011) did not assess whether the initiation of the intrinsic coagulation pathway following exposure was a consequence of an inflammatory response and/or particle translocation processes [62]. Interestingly, Budinger et al. (2011) suggested that IL-6 is significantly as- sociated with PM-induced thrombogenic effects independ- ent of other inflammatory markers [61]. Two studies have been published examining the effect of anti-inflammatory agents on thrombogenic factors in mice following exposure to DEP (15–30 μg) [66, 67]. Both studies demonstrated a critical role for inflammation in mediating DEP-induced thrombotic effects [66, 67]. Interestingly, the Nemmar et al. (2003) found that inflammation and thrombosis were asso- ciated events at 18 h, but not at 4 h [68]. Particle transloca- tion could play a role in the early pro-thrombotic effects of DEP, with inflammation playing a greater role at later stages. Indirect evidence for this concept is provided by the finding that intravenous administration of DEP to the blood has the capacity to increase in vivo thrombosis formation at 2 h, without inducing inflammation [69]. The link between inflammation and thrombosis at later time points after pulmonary instillation is possible (6–24 h), but complex [69]. Smyth et al. (2017) showed intratracheally instillation of DEP (25 μg) in mice to induce platelet aggregation inde- pendent of lung inflammation [70]. The study also showed that platelet aggregation persisted in endothelial nitric oxide synthase (eNOS) knockout mice [70], suggesting a lesser influence of vascular-derived mediators in actions of DEP on platelets. There is some discrepancy regarding the role of platelets in mediating the pro-thrombotic effects of par- ticulate air pollution [13, 51, 52, 60–62, 69, 70]. This is likely due to differences in study designs, including species, particle types, doses, exposure methods and different meas- urable indicators of platelet function. An especially note- worthy study is that by Emmerects et al. (2012) suggesting that continuous exposure of mice to traffic-related air pol- lution, in a real-life setting (mice were placed in a highway tunnel for 25 or 26 days; mean 24.9 μ g/m 3
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PEDIATRIC ASPECTS OF AIR POLLUTION

PEDIATRIC ASPECTS OF AIR POLLUTION

Sulfur dioxide, sulfuric acid Increased respiratory infections None reported. Oxidants:[r]

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Air Pollution and Children’s Health

Air Pollution and Children’s Health

What is important to realize is that this is an easily modifiable risk. Sulfate particles, a major fraction of the particle burden in the air in urban areas, can be easily removed using scrubbers on powerplants (their largest source) at a cost that is ⬍ 1% of the current price of electricity. NOx reduction, a major component of an ozone reduction strategy, can also be retrofitted onto powerplants. In Europe, catalytic converters on cars can be brought up to US stan- dards. Traffic particles, NOx, and so forth are dom- inated by diesel engines. Trap oxidizers and catalysts can reduce these emissions by up to 90%. Such de- vices have been on gasoline-powered vehicles for decades without ending industrial civilization as we know it. For many of these control strategies, it does not matter that we are not sure which component of the pollution mix is principally responsible. Oxida- tive catalysts reduce carbon soot, polycyclic aromatic hydrocarbons, CO, and so forth. Given the amount of money that we spend on the treatment of asthma and the difficulty that we have in reducing allergen ex- posures, such straightforward approaches need seri- ous attention.
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Air pollution monitoring and modelling in RTH East Derbyshire

Air pollution monitoring and modelling in RTH East Derbyshire

Previous work on biological monitors for atmospheric lead has been reviewed. Experiments with hair-net and flat nylon-mesh envelope monitors failed to confirm a claim of reproducibility by previous workers, a percentage relative standard deviation of 24.5 for hair-net monitors and 13.4 to 56.7 for flat nylon-mesh envelopes was achieved. An homogenised acid-washed moss monitor in a diffusion tube produced a significant increase in lead deposition. Replicate diffusion tube monitors initially showed poor reproducibility. Homogenisation of the moss to < lram and maintained saturation produced a range of % RSD’s of 8.6 to' 12.8. Samples unwashed with acid showed more depostion than washed samples. Replicate monitors in which moss was replaced with various physical media displayed poor reproducibility. It seems unlikely that such passive monitors can replace established air filtration methods.
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The Happiness Cost of Air Pollution

The Happiness Cost of Air Pollution

Air pollution is a kind of social public goods, and there is a certain difficulty in pricing it. This paper mainly uses the “subjective well-being” method to eva- luate, mainly through the measurement of more or less pollution to measure positive or negative effect on subjective well-being, and the positive effect of in- come increasing to happiness, so that to calculate the residents’ willingness to pay for environmental goods. On the basis of previous research, this paper as- sumes that the happiness can only be affected by the air pollution and the in- come level of residents can be liked as this: H = F ( M , Q ). H represents the sub- jective well-being of the residents, and M represents income and Q represents environmental pollution. Based on the above hypothesis, we can easily estimate the residents’ willingness to pay for air pollution. The principle is to regard all people as rational brokers. The hypothesis of utility maximization is that the marginal utility of air pollution reduction is equal to the marginal utility brought by income increase. Just as: dH = 0, the following formula can be obtained:
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Air pollution, epigenetics, and asthma

Air pollution, epigenetics, and asthma

Given the increasingly evident health impact of TRAP, methodologies to accurately assess exposure are needed. While TRAP affects air quality on urban and regional scales, their impact is greatest on a local scale, particu- larly near roadways, as their concentrations are sig- nificantly elevated within approximately 300–500  m of their source [36]. Further influencing individuals’ TRAP exposure is its temporal variability combined with com- plex and variable personal behavior including time spent indoors/outdoors [37]. In order to meet the intrin- sic challenge of accurately assessing TRAP exposure for epidemiologic studies both modeling and personal measurement approaches have been utilized. Because particulate matter (PM) is a complex mixture of chemical and elemental constituents, recent studies have focused on assessing exposure and associating health effects with specific elemental PM components, rather than the more traditionally used total PM mass. Most notably, the large ESCAPE project has developed land use regression models for particle composition in twenty study areas in Europe [38]. Accurate and precise models were built for
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Air pollution and livestock production

Air pollution and livestock production

ABSTRACT The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings.
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Effects of Air Pollution on Children

Effects of Air Pollution on Children

air pollution in the first year of life does have an effect on mortality from respiratory disease and other conditions,’ but we cannot show an effect in.. later periods.[r]

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Mathematical modelling in the river pollution

Mathematical modelling in the river pollution

Water quality modelling involves the prediction of water pollution using mathematical simulation techniques. A typical water quality model consists of a collection of formulations representing the physical situation of pollutants in water. Laplace method is used to calculate the solution of the model and then interpreted and validated the solution accoding to the physical situation.

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Air Pollution Monitoring System

Air Pollution Monitoring System

Currently, the application aggregates data from various sources, processes it, formats it appropriately, and visualizes it for the user. The application relies on data collected at specific points where a metering station or a specialized sensor is located. However, users often want to check the air quality in a location where measurements are not actually taken. Another important feature is a short-term forecast for air quality. This sets additional requirements for the developed application:

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Modelling for sustainable cities: Conceptual approach and an audit of existing sectoral models for transport, air pollution, land use, and population modelling.

Modelling for sustainable cities: Conceptual approach and an audit of existing sectoral models for transport, air pollution, land use, and population modelling.

Dispersion models have to take into account all atmospheric processes affecting polluting species after an emission from a source (Figure B-1) (Seinfeld 1975). These are: transport of air masses by the wind (advection); diffusion; chemical and photochemical reactions; and physical processes such as dry (gravitational) and wet deposition. These processes take place in the boundary layer, the lower part of the troposphere. The mixing height, above which there is free troposphere, depends on the time of the day, meteorological conditions, and on the latitude, and is from 0.5 to 1.5 km. Diffusion is responsible for mixing of pollutants with the remaining components of the atmosphere, while the wind transports pollutants far away from the source. Typically, pollutants can travel several tens of kilometers within several hours and thousands of kilometers within several days, crossing countries boundaries. During temperature inversion and calm weather conditions, dispersion is greatly reduced and one observes cumulation of pollutants near the sources. B.4.1 Dispersion models
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