Residential Sources Research Articles

Distribution of environmentally persistent free radicals in size-segregated PMs emitted from residential biomass fuel combustion

Environmentally persistent free radicals (EPFRs) are considered as an emerging pollutant due to their potential environmental risks, but the distribution characteristics of particulate matters (PMs)-EPFRs from residential combustion source are poorly understood. In this study, biomass (corn straw, rice straw, pine and jujube wood) combustion was studied in lab-controlled experiments. More than 80% of PM-EPFRs were distributed in PMs with aerodynamic diameter (dae) ≤ 2.1 µm, and their concentration in fine PMs was about 10 times that in coarse PM (2.1 µm ≤ dae ≤ 10 µm). The detected EPFRs were carbon-centered free radicals adjacent to oxygen atoms or a mixture of oxygen- and carbon-centered radicals. The concentrations of EPFRs in coarse and fine PMs were positively correlated with char-EC, but the EPFRs in fine PMs exhibited a negative correlation with soot-EC (p < 0.05). The increase of PM-EPFRs signals with the increased dilution ratio during pine wood combustion was more significant than that from rice straw, which may be resulted from the interactions between the condensable volatiles and the transition metals. Our study provides useful information for better understanding the formation of combustion-derived PM-EPFRs, and will be instructive for its purposeful emissions control.

Sound masking of residential noise by a birdsong depending on spectral and temporal characteristics

This study aimed to investigate the sound masking according to spectral and temporal characteristics of residential noise and natural sound through auditory experiment. Since there are various types of residential noise sources (maskee) and natural sounds (masker), stimuli to be used for experiment were selected by dividing the sound source groups through the k-means cluster method. The stimuli consisted of a total of 7 maskee including a brown noise, and 7 masker (birdsongs and water sounds). In the auditory experiment, the preference of masker and the annoyance and unpleasantness of single maskee and masker and mixed sources (maskee+masker) were investigated. Result showed that Phoenicurus auroreus and stream-Fast were the highest preference among masker, and masker preference were significantly correlated with masker annoyance. In addition, it was found that impact sound (children jumping and running and piledriver) show relatively higher annoyance than other sound sources. Relative annoyance of mixed sources (maskee+masker) to single maskee was analyzed and masking effect was discussed based on spectral and temporal and the Zwicker's parameters of each sound source.

Exploring the contributions of major emission sources to PM2.5 and attributable health burdens in China

Ambient fine particulate matter (PM2.5) pollution is the principal environmental risk factor for health burdens in China. Identifying the sectoral contributions of pollutant emissions sources on multiple spatiotemporal scales can help in the formulation of specific strategies. In this study, we used sensitivity analysis to explore the specific contributions of seven major emission sources to ambient PM2.5 and attributable premature mortality across mainland China. In 2016, about 60% of China's population lived in areas with PM2.5 concentrations above the Chinese Ambient Air Quality Standard of 35 μg/m3. This percentage was expected to decrease to 35% and 39% if industrial and residential emissions were fully eliminated. In densely populated and highly polluted regions, residential sources contributed about 50% of the PM2.5 exposure in winter, while industrial sources contributed the most (29–51%) in the remaining seasons. The three major sectoral contributors to PM2.5-related deaths were industry (247,000 cases, 35%), residential sources (219,000 cases, 31%), and natural sources (87,000, 12%). The relative contributions of the different sectors varied in the different provinces, with industrial sources making the largest contribution in Shanghai (65%), while residential sources predominated in Heilongjiang (63%), and natural sources dominated in Xinjiang (82%). The contributions of the agricultural (11%), transportation (6%), and power (3%) sources were relatively low in China, but emissions mitigation was still effective in densely populated areas. In conclusion, to effectively alleviate health burdens across China, priority should be given to controlling residential emissions in winter and industrial emissions all year round, taking additional measures to curb emissions from other sources in urban hotspots, and formulating air pollution control strategies tailored to local conditions.

Analysis of Pollution Characteristics and Emissions Reduction Measures in the Main Cotton Area of Xinjiang.

With cotton production in Xinjiang increasing annually, the impact on the environment of agricultural waste produced to improve production has been reflected. This study selected Bozhou of Xinjiang, the main cotton producing region in northern Xinjiang, as the research object, and collected hourly concentration data of six pollutants from 2017 to 2021, and analyzed the spatial and temporal distribution characteristics of each pollutant. At the same time, Morlet wavelet analysis was used to further analyze the variation period of PM2.5 (PM particles with aerodynamic diameters less than 2.5 μm) concentration. The Weather Research and Forecasting model coupled with the Community Multiscale Air Quality (WRF-CMAQ) model was used to evaluate the emissions reduction measures for the most polluted month. The results showed that the concentration of particulate matter (PM particles with aerodynamic diameters less than 2.5 μm and 10 μm) decreased from the southern mountains to the north; moreover, the concentrations of CO (carbon monoxide), NO2 (nitrogen dioxide), and SO2 (sulfur dioxide) in the suburbs were higher than those in the urban center. The concentration of O3 (Ozone) was the highest in summer, while the concentrations of other pollutants were high in autumn and winter. Under the time scale of a = 13, 24, PM2.5 had significant periodic fluctuation. The health risk values of PM2.5 and PM10 in this study were within the scope of the United States Environmental Protection Agency (USEPA) criteria, but it is still necessary to keep a close watch on them. In the context of emissions reduction measures, agricultural sources reduced by 20%, residential sources by 40%, industrial sources by 20%, and transportation sources by 20%; no change in the power source remains. Under these conditions, the daily average value of each pollutant met the first level of the national ambient air quality standard. The research results provide a reference for the local government to formulate heavy pollution emissions reduction policies.

A Group Resident Daily Load Forecasting Method Fusing Self-Attention Mechanism Based on Load Clustering

Daily load forecasting is the basis of the economic and safe operation of a power grid. Accurate prediction results can improve the matching of microgrid energy storage capacity allocation. With the popularization of smart meters, the interaction between residential electricity demand and sources and networks is increasing, and massive data are generated at the same time. Previous forecasting methods suffer from poor targeting and high noise. They cannot make full use of the important information of the load data. This paper proposes a new framework for daily load forecasting of group residents. Firstly, we use the singular value decomposition to address the problem of high dimensions of residential electricity data. Meanwhile, we apply a K-Shape-based group residential load clustering method to obtain the typical residential load data. Secondly, we introduce an empirical mode decomposition method to address the problem of high noise of residential load data. Finally, we propose a Bi-LSTM-Attention model for residential daily load forecasting. This method can make full use of the contextual information and the important information of the daily load of group residents. The experiments conducted on a real data set of a power grid show that our method achieves excellent improvements on five prediction error indicators, such as MAPE, which are significantly smaller than the compared baseline methods.

The influence of regional transport on the three-dimensional distributions of black carbon and its sources over eastern China

Regional transport is deemed the key physical process affecting air pollution formation. Previous studies have indicated that black carbon (BC) is abundant and unevenly distributed over eastern China, but the details of its three-dimensional (3-D) distributions and sources are still lacking. In this study, based on vertical observations and by using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) coupled with the BC-tagging technique, we explored the 3-D distributions and sources of BC under two typical winter pollution events in eastern China, namely, one induced by cold front transport (TRAN) and another induced by stagnant weather (STAG). During TRAN, cold air can transport BC from upwind (North China Plain, NCP) to downwind (Yangtze River Delta, YRD) regions, thereby making the source region components of BC more diversified over the YRD than during STAG. It also significantly increased the proportion of BC residential sources in the YRD. The higher the altitude is, the higher the ratios of BC sources originating from long-range transport are. In TRAN, except for horizontal advection, which plays a key role in the distribution of BC, a stronger vertical advection changes the BC profiles and raises the boundary layer height as the cold front moves through. In particular, high-concentration BC from regional transport arrives earlier at the upper BL of downwind regions than at the surface, thus exerting a distinct positive vertical mixing effect on the surface BC. This study implies that regional transport can significantly impact BC evolution and further affect meteorology and climate on a large scale.

Ecological Study on Global Health Effects due to Source-Specific Ambient Fine Particulate Matter Exposure.

Ambient air pollution of fine particulate matter with diameters less than 2.5 μm (PM2.5) is associated with millions of premature deaths per year, recognized as a leading global health concern. The dose-response relation between ambient PM2.5 exposure and mortality risk is the most fundamental information for assessments of the health effects of PM2.5. The existing dose-response relations were generally developed based on the assumption of equal contribution to toxicity from various sources. However, the sources of PM2.5 may significantly influence health effects. In this study, we conducted an ecological study to investigate the global long-term correlation between source-specific PM2.5 exposure and cause-specific mortality risk (SPECM) based on the regional aggregate data of the publically available official health databases from 528 regions worldwide with a total registered population of 3.2 billion. The results provided preliminary epidemiological evidence for differing chronic health effects across various sources. The relative mortality risks of lung cancer and circulatory diseases were closely correlated with the primary emissions from industrial and residential combustion sources. Chronic lower respiratory diseases were mostly associated with the mass concentration of particulate matter.

Reaction of HOCl with Wood Smoke Aerosol: Impacts on Indoor Air Quality and Outdoor Reactive Chlorine.

High loadings of biomass burning (BB) aerosol particles from wildfire or residential heating sources can be present in both outdoor and indoor environments, where they deposit onto surfaces such as walls and furniture. These pollutants can interact with oxidants in both the aerosol and deposited forms. Hypochlorous acid (HOCl), a strong oxidant emitted during cleaning with chlorine-cleaning agents such as bleach, can attain mixing ratios of hundreds of ppbv indoors; moreover, lower mixing ratios are naturally present outdoors. Here, we report the heterogeneous reactivity of HOCl with wood smoke aerosol particles. After exposure to gas-phase HOCl, the particle chlorine content increased reaching chlorine-to-organic mass ratios of 0.07 with the chlorine covalently bound as organochlorine species, many of which are aromatic. Investigating individual potential BB components, we observed that unsaturated species such as coniferaldehyde and furfural react efficiently with HOCl. These observations indicate that organochlorine pollutants will form indoors when bleach cleaning a wildfire impacted space. The chlorine component of particles internally mixed with BB material and chloride initially increased, upon HOCl exposure, indicating that active chlorine recycling in the outdoor environment will be suppressed in the presence of BB emissions.

Absorption of Carbon Dioxide Emissions from Industrial and Residential Sources by Green Open Space in Sukorejo Village, Gresik

Absorption of Carbon Dioxide Emissions from Industrial and Residential Sources by Green Open Space in Sukorejo Village, Gresik

Analysis and Characterization of Municipal Solid Wastes Generated in a Community in the Northern Philippines

The residential community of Potia in the Northern Philippines experiences various problems arising from mismanaged municipal solid waste. Hence, a waste analysis and characterization study on the generated municipal solid wastes was conducted to determine the municipal solid waste generation data which can be used for planning and formulation of potential solutions. For three consecutive days, the generated municipal solid wastes were gathered from the sample which included residential sources, commercial sources (food establishments, service centers, general stores, and markets), industrial sources, and institutional sources (institutions and health units). The total generated municipal solid waste in Potia is about 508.30 kg.day-1 of which most were contributed by the residential sources (70.59%), followed by commercial (25.09%), industrial (2.64%), and institutional (1.70%). The overall composition of the generated MSW is also dominated by biodegradable waste (76.90%), followed by residual waste (14.66%), recyclable waste (7.35%), and special waste (1.08%). The total volume of daily generated MSW is about 3.37 m3.day-1.

Energy-related CO2 emissions of urban and rural residential buildings in China: A provincial analysis based on end-use activities

The residents' energy consumption and CO2 emissions in China continue to increase. There are significant differences between provinces, urban and rural areas in terms of economic development levels, energy consumption behaviors, climatic conditions, etc. An analysis focusing on these factors will be helpful for a better understanding of the CO2 emissions in this sector. Thus, a bottom-up Adaptive Weighting Divisia decomposition model was established to analyze the inherent differences in the per capita CO2 emissions across urban and rural areas of different provinces from the perspective of end-use activity based on multiple sources of data. The results show that the average household CO2 emissions in urban consistently exceeded those in rural. The residential energy source is gradually transitioning from coal and biomass to electricity, heat, and natural gas. Inner Mongolia has been the province with the highest per capita CO2 emissions since 2008, with an average annual growth rate of 12.39%. Provinces with high CO2 emissions are mainly concentrated in northern China, and the CO2 emissions were mainly influenced by heating. The end-use energy intensity and activity were mainly affected by heating, cooking and water heating, and household appliances, with the greatest impact on the CO2 emissions from the residents.

PM2.5 source apportionment using organic marker-based chemical mass balance modeling: Influence of inorganic markers and sensitivity to source profiles

A Chemical Mass Balance (CMB) model has been applied to source apportionment of PM2.5 in the Chinese megacity of Chengdu. The study explored the sensitivity of the CMB model to the adoption of different organic source profiles, and to the use of organic markers only (OM-CMB), compared with using a combination of organic and inorganic markers (IOM-CMB). A comprehensive comparison of OM-CMB and IOM-CMB shows that PM2.5 mass concentrations from gasoline vehicles, diesel vehicles, industrial coal combustion, biomass burning, cooking, and SOA which shared same markers in the two methods are in fair to good agreement between the two methods, with the relative biases ranging from 2.2% to 17.3%. The average contributions of sulfate and nitrate sources are more sensitive to the choice of model because inorganic ions were not inputted directly into the OM-CMB. The temporal variations of PM2.5 contributions from sulfate, nitrate, SOA, gasoline vehicles, and biomass burning, characterized by unique markers and low collinearity, were in good agreement between the OM-CMB and IOM-CMB results with the Pearson's r above 0.91 (p < 0.01). However, resuspended dust estimates from OM-CMB had a relatively weak correlation with that from IOM-CMB (Pearson's r = 0.73, p < 0.01), due to the different tracers used. When replacing the source profile for industrial coal combustion with that for residential sources, the contributions of resuspended dust and residential coal combustion were higher, and the contributions of other sources were lower compared with the result for the industrial coal combustion. Different source profiles for gasoline vehicles showed considerable sensitivity of the model to the choice of source profile, even when using data from within a single emissions study. Our results emphasize the value of combining inorganic and organic tracers in minimizing error, and in using up-to-date locally-relevant source profiles in source apportionment of PM.

A review of untreated household greywater quality to inform the water saving–risk trade-off in South Africa

Interest in greywater reuse is increasing in South Africa, because of the potential to supplement scarce freshwater resources in the face of increasing demand and aridity. This paper aims to inform the water saving–risk trade-off associated with residential untreated greywater use, through a statistical analysis of greywater quality results as sourced from prior South African studies. Greywater sources included in this review were the bathroom, kitchen, laundry, mixed and general residential sources. Variability in terms of each of the reported physical, chemical and microbiological constituents by source and between result sets was noted. Statistically significant differences were evident between the pH, conductivity and phosphorus values of certain sources. A risk assessment undertaken for each of the constituents revealed further variability. The constituent with the highest number of high-risk samples was total dissolved solids. The relatively high risk and negative consequences in greywater practices in terms of public health, the environment, and infrastructure, given this variability, provide insight into the trade-off with potential water savings. It is recommended that a more nuanced view of the potential potable savings associated with greywater reuse and also improved risk management is required by the user.

Mechanistic and recent updates in nano-bioremediation for developing green technology to alleviate agricultural contaminants.

The rise in environmental pollutant levels in recent years is mostly attributable to anthropogenic activities such as industrial, agricultural and other activities. Additionally, these activities may produce excessive levels of dangerous toxicants such as heavy metals, organic pollutants including pesticide and herbicide chemicals, and sewage discharges from residential and commercial sources. With a focus on environmentally friendly, sustainable technology, new technologies such as combined process of nanotechnology and bioremediation are urgently needed to accelerate the cost-effective remediation process to alleviate toxic contaminants than the conventional remediation methods. Numerous studies have shown that nanoparticles possess special qualities including improved catalysis and adsorption as well as increased reactivity. Currently, microorganisms and their extracts are being used as promising, environmentally friendly catalysts for engineered nanomaterial. In the long term, this combination of both technologies called nano-bioremediation may significantly alter the field of environmental remediation since it is more intelligent, safe, environmentally friendly, economical and green. This review provides an overview of soil and water remediation techniques as well as the use of nano-bioremediation, which is made from various living organisms. Additionally, current developments related to the mechanism, model and kinetic studies for remediation of agricultural contaminants have been discussed.

Sources and discharge of nitrogen pollution from agriculture and wastewater in the Mesoamerican Reef region

Land-based nitrogen pollution is a major threat to coastal ecosystems, especially in tropical regions home to high biodiversity habitats such as coral reefs and seagrass beds. The sustained addition of excess nutrients (in the form of nitrates) to these ecosystems, which are adapted to oligotrophic environments, disrupts ecosystem function and the ability to provide services that support livelihoods and benefit human well-being. Nitrogen (N) primarily originates from agricultural crop production, livestock waste, and human sewage, as well as excretion from seabird and feral ungulates for some small atolls and cayes. Determining the most effective mitigation strategies to reduce N pollution in a given location begins with identifying and quantifying input from the source. Here we model four major sources of N pollution – crop production, livestock production, wastewater generated from permanent residents and wastewater generated from seasonal populations – at the regional scale, measuring inputs and impacts from 430 watersheds that drain into the Mesoamerican Reef region. We find that leaching of fertilizer from crop production and runoff associated with livestock contribute the majority of N pollution (92%), while contributions from residential and tourism wastewater sources were lower (8%). A north-south divide in N pollution was observed, with watersheds from the south, Guatemala and Honduras, associated with the highest levels of N pollution. The top 20 most polluting watersheds contributed nearly 90% percent of N pollution from all sources analyzed to the MAR, with the majority (11) located in the southern part of the MAR. The top two most polluting watersheds on their own, the Rio Ulua, Honduras, and Rio Motagua, Guatemala, contribute approximately 50% percent of the total N input to the MAR. However, high biodiversity habitats were more exposed to plumes originating from smaller, coastal watersheds. Our approach provides a map of the N pollution in the region highlighting hotspots for managers to target for mitigation, as well as the main sectors and industries to engage when designing solutions.

Source Apportionment of PM2.5 Based on Hybrid Chemical Transport and Receptor Model in Chongqing

In order to further improve the accuracy of fine particulate matter (PM2.5) source apportionment results, a hybrid source apportionment approach (CTM-RM) combining the capabilities of a receptor model (RM) and chemical transport model (CTM) was developed. The CTM-RM method was evaluated and applied according to a typical PM2.5 pollution process from January 21 to 27, 2019 in Chongqing. The average value of square prediction error based on CTM-RM was 84.58% lower than that of CAMx/PSAT during the campaign. Compared with that of CAMx/PSAT, the fractional error of PM2.5 and its chemical component concentrations decreased by 15.69%-92.86%. Furthermore, the temporal and spatial variations in PM2.5 source impacts could be obtained using the CTM-RM method in Chongqing. The average adjustment factor (R) values were 1.39±0.38 (agriculture sources), 1.54±0.48 (industrial sources), 1.01±0.13 (power sources), 1.02±0.58 (residential sources), 0.86±0.59 (transportation sources), and 0.58±0.67 (other sources) in the main urban areas of Chongqing. Additionally, the cumulative distribution functions of R were found to be distinct among the six sources. The residential and industrial sources were the main sources of PM2.5, with contributions of 46.23% and 28.23%, respectively. In contrast to that of the other sources, the transportation source impacts of PM2.5 (8.62%) increased significantly from the clear period to pollution period (P<0.001), indicating that the increase in PM2.5 concentrations was mainly driven by vehicular emissions during the pollution period in the main urban areas of Chongqing. The fitting functions between the initial simulated concentrations and R values of each source in the main urban areas of Chongqing could be used to evaluate PM2.5 concentrations at 47 air quality monitoring stations in Chongqing, and the correlation between the refined simulated concentrations and measured concentration of PM2.5 was significant (r=0.82, P<0.001). Compared with that during the clear period, the increases in the percentages of industrial source impacts of PM2.5 in Northeast Chongqing and residential source impacts of PM2.5 in Southeast Chongqing were 17.20% and 9.15% higher, respectively, than that in other areas during the pollution period. By contrast, the increasing percentage of transportation source impacts of PM2.5 in the main urban areas of Chongqing (66.39%) and Western Chongqing (84.16%) from the clear period to the pollution period were higher than that in other areas. The results of CTM-RM on January 26 indicated that the residential source impacts in Northeast Chongqing (64.56%) were higher than those in other areas, and the industry source impacts of PM2.5 were primarily observed in the main urban areas of Chongqing and Western Chongqing, with contributions of 25.26% and 21.20%, respectively.

Weakened Haze Mitigation Induced by Enhanced Aging of Black Carbon in China

A great challenge for haze pollution mitigation with the existing emission control measures in China is ozone (O3) increase. The chemical processes leading to weakened haze mitigation are still poorly understood. Our work identifies the enhanced aging chemistries of black carbon (BC) with increasing O3 as an essential driver to weaken haze mitigation based on field observations during autumn/winter haze periods in 2014 and 2018 in North China Plain. The enhanced atmospheric oxidation capacity induced by increasing O3 promotes the initial aging of accumulated fresh BC from continuous emission under haze pollution conditions and consequently improves the hygroscopicity of BC-containing particles to provide more particulate surfaces and volumes for aqueous and heterogeneous chemistries. The enhanced BC aging amplifies PM2.5 concentrations by ∼20%, which can be broken by concurrent reductions in multipollutant emissions (i.e., BC, nitrogen oxides, and volatile organic compounds), especially from residential and industrial sources. Moreover, enhanced BC aging implies an adverse effect of O3 increase on climate change. Observationally enhanced BC aging will help to constrain estimations of the interactions among O3 increase, haze pollution, and climate warming in recent years in China.

Emission Sector Impacts on Air Quality and Public Health in China From 2010 to 2020.

Anthropogenic emissions and ambient fine particulate matter (PM2.5) concentrations have declined in recent years across China. However, PM2.5 exposure remains high, ozone (O3) exposure is increasing, and the public health impacts are substantial. We used emulators to explore how emission changes (averaged per sector over all species) have contributed to changes in air quality and public health in China over 2010–2020. We show that PM2.5 exposure peaked in 2012 at 52.8 μg m−3, with contributions of 31% from industry and 22% from residential emissions. In 2020, PM2.5 exposure declined by 36% to 33.5 μg m−3, where the contributions from industry and residential sources reduced to 15% and 17%, respectively. The PM2.5 disease burden decreased by only 9% over 2012 where the contributions from industry and residential sources reduced to 15% and 17%, respectively 2020, partly due to an aging population with greater susceptibility to air pollution. Most of the reduction in PM2.5 exposure and associated public health benefits occurred due to reductions in industrial (58%) and residential (29%) emissions. Reducing national PM2.5 exposure below the World Health Organization Interim Target 2 (25 μg m−3) would require a further 80% reduction in residential and industrial emissions, highlighting the challenges that remain to improve air quality in China.

Investigating the relationship between mass concentration of particulate matter and reactive oxygen species based on residential coal combustion source tests

Particulate matter (PM) has been considered to be closely related to human health, especially fine particulate matter. However, whether PM mass concentration alone is a good indicator for health impact remains a challenging question. In this study, emissions from residential coal combustion (RCC), one of the important PM sources in northern China, were tested to examine the relationship between the emission factors of particle-generated reactive oxygen species (ROS) (EFROS) and PM (EFPM). A total of 24 combinations of source tests were conducted, including eight types of coal with different geological maturities (two anthracites and six bituminous) burned in three types of stoves (one honeycomb coal stove, one old chunk stove, and one new chunk stove). Here, ROS was defined as generated hydroxyl radical (·OH) by PM, and results showed EFROS from 24 residential coal combustion varied greatly by nearly 20 times. EFROS ranged 0.78–14.85 and 2.99–12.91 mg kg−1 for the emissions from honeycomb and chunk coals, respectively. Moreover, the correlation between EFROS and EFPM was significantly positive in honeycomb coal emissions (r = 0.82, p < 0.05), but it was insignificant in chunk coal emissions (r = 0.07, p > 0.05). For honeycomb coal emissions, organic carbon (OC) was quite abundant in PM and it might be the predominant contributor to both EFPM and EFROS, resulting in a strong and positive correlation. For chunk coal emissions, high EFROS was mainly related to relatively high metal emissions in AN and LVB, while the metals were not major components in PM, leading to a poor correlation between EFPM and EFROS. Therefore, this study revealed that PM was not always positively correlated with ROS from residential coal burning, and the relationship was mainly determined by the compositions of PM, suggesting PM mass concentration alone may not be the best indicator for assessing health impacts.

Estimation of Air Pollutant Dispersion Levels Using AERMOD: A Case Study in Ambattur, Chennai, India

The present study is proposed to determine the possibility of using AERMOD (Gaussian dispersion air quality model) to estimate the air pollutant levels of Ambattur Municipality, Chennai. Four main pollutants PM10, CO, SO2, and NOx were considered in this study. The metrological data were obtained from CPCB for comparison with the model’s output. The primary pollution sources used in this study were classified as residential, commercial, traffic, and industrial sources. Emission characteristics were taken as source input to estimate the pollutant concentration from the study area based on the Top-Down Approach method (TDA). Results clearly show that the pollutant dispersion concentrations retrieved from the model were much lower than the measured values in all parameters. The values obtained from the model were 5.14% to 76.88% of the measurement values. This could be due to an incomplete source account. However, the model can be used for knowing the pollutant dispersion of the urban area.