Spatial Distribution Of Air Pollutants Research Articles

Rapid urban growth, land-use changes and air pollution in Santiago, Chile

This paper is a contribution to the understanding of the topoclimatic and environmental geography of the basin where Santiago — one of the most polluted Latin American city – is located. In the first part, land-use change is analysed looking at the climatic transformation caused by the rapid transit from natural semiarid surface to urban areas. In the second part, seasonal weather and daily cycles of slope winds and the available ventilation are described trying to relate those patterns with the spatial distribution of air pollution. A combination of meteorological, geographical and cultural factors explain extreme air pollution events: meteorologically, Santiago is under permanent subsidence inversion layers. Geographically, the city is located in a closed basin surrounded by mountains. Culturally, the urban area has the highest population concentration (40% of the national total), industries (near 70% of the total) and vehicles, which are the main sources of smog. The urban and suburban transport system is based on a large number of buses (diesel) and private cars, both experiencing a rapid growth from the past few years. The city and specially the transport system generates high emissions of pollutant, but the natural semiarid deforested soils and slopes are also important sources. The local wind system can explain the differential spatial distribution on the concentration of air pollutants in the city and its periphery. In winter (rain season) concentrations of particulate matter are higher at the centre and the SW part of the city. The andean piedmont area (E part of the city) shows minimum values, suggesting major ventilation effects of slope and valley winds. Ozone exceeds air quality standards in summer (dry season) at all sites in the centre and periphery. However, the O 3-concentrations are higher on preferred residential areas located at the piedmont area (E part of the city), suggesting air pollution transport effects. Currently, there is no consideration of these local climatic features in the process of urban planning.

A study of spatial distribution of air pollutants in some coal mining areas of Raniganj coalfield, India

Ambient air quality monitoring for suspended particulate matter, sulphur dioxide, and nitrogen oxides was carried out over a period of one year to study diurnal and seasonal variations and spatial distribution of said pollutants. Dustfall rate measurements were carried out for a period of one month out of each season and for all the four seasons of the year. Studies were also carried out at selected work places to determine levels of the above-mentioned pollutants. Studies indicate that mining and associated activities have raised the background levels of particulate pollution in the region. The coal handling plant and poorly maintained roads, resulting in transport of coal dust by means of wind, are identified as the sources of particulate pollution in a coal mining area. Coal burning and transportation activities appear to be major sources of SO 2 and NO x in coal mining areas.

Planning for the monitoring of pollutants from non‐stationary combustion sources†

Abstract The most important constituents of traffic exhaust are carbon monoxide, nitrogen oxides, volatile organic compounds, polycyclic hydrocarbons and lead. Satisfactory analytical methods are available for measuring these compounds, but the required expenditure in their application to air pollution studies is quite different. Due to correlations between the concentrations of several exhaust components in road air conclusions regarding the expected level of some substances can be drawn by measurement of another emitted compound. But the selection of indicator compounds must be made under the aspect of the source‐specific relationship of emitted substances. The temporal and spatial distribution of air pollutants in street air is affected by traffic emissions more than by meteorological conditions. “Fingerprints”; of typical organic gaseous components of traffic exhaust also were found in residential areas.

Computer Mapping of Air Quality

A methodology for mapping the spatial distribution of air pollutants by computer is presented. Using input data from discretely located air monitoring stations, estimates of pollutant concentrations are computed at 1.2-mile (2-km) increments between stations by two-dimensional interpolation. Maps are then printed to show the resulting distribution. Application of this technique to mapping the oxidant distribution in a select study area is demonstrated. Oxidant data are displayed in both measured units (e.g., pphm) and as Pollutant Standards Index values. Practical applications examined include the use of mapping to site air monitoring stations, providing public information, preparation of environmental impact studies, and conducting trend analyses.