Components of pollution – An overview
With the rising pollution levels throughout the world it is becoming vital to be aware about the elements which causes pollution. Leaders all over the world are engaged in debates and negotiations over environmental concerns. Environmental education is being focused upon to strengthen the future generation from the very beginning.
The presence of contaminants or pollutant substances in the air that interfere with human health or welfare, or produce other harmful environmental effects.” (EPA, 2007)
The substances that are directly emitted into the atmosphere from sources. Such as: Compounds of Carbon, Nitrogen, Sulphur, Halogen, PM (PM or “aerosols”), either in solid or liquid form.
The substance that are not directly emitted from sources, but instead form in the atmosphere from primary pollutants. Such as: NO2 and HNO3, Ozone (O3), Sulfuric acid droplets formed from SO2.
These sources are defined as sources that emit less than 10 tons per year of a criteria or hazardous air pollutant or less than 25 tons per year of a combination of pollutants. The category also includes commercial buildings (heating and cooling units; surface coatings), residential buildings (fire places; surface coatings), fuel combustion in non-road machinery, boats, railroads, and even the family lawnmower or barbecue grill. Waste disposal in the form of open burning, landfills and wastewater treatment are significant area sources. (GoodGuide, 2011)
Mobile sources include both on road vehicles (such as cars, trucks and buses) and off-road equipment (such as ships, airplanes, agricultural and construction equipment).
Point Sources Point sources include major industrial facilities like chemical plants, steel mills, oil refineries, power plants, and hazardous waste incinerators. Point sources are defined as those that emit 10 tons per year of any of the criteria pollutants or hazardous air pollutants or 25 tons per year of a mixture of air toxics.
Example of cities struggling with environmental pollution
Since 1960s, environmental quality had been rapidly worsening in Seoul, the capital of Korea. SOx, CO and O3 concentrations are now being maintained under national standards. NO2 levels still need to be managed intensively.
However, the management of air pollution is not simple, because of the criteria which are used in studies or for policy suggestions are limited to concentrations and emission volume of air pollutants. It is essential to have the knowledge about types of data processing to make any use of available data.
With the concentrations and emission volume of air pollutants that are currently used, it is difficult to determine the exact source location and emission volume of the air pollutants. To cope with such pollution problems, the trajectory model can be adopted to deduce the location of an air pollutant source and the emission volume.
Seoul, the capital of South Korea with area of 605.2 sq.km.
Population: 10 Million
The trajectory model was applied to Seoul, the capital of Korea. Seoul is one of the densest cities in the world in which 21.5% of the country’s total population reside within 0.6% of land area. Therefore, Seoul is vulnerable to atmospheric pollution and the air quality needs to be managed continuously. The study area that was analyzed extends to the location of the air pollution sensors and those near Seoul.
Results of Correlation Analysis
The emission volume that was derived by the trajectory model is expressed in grid cells with the resolution of 500m x 500m. Each cell has the variables of naturalness, land-use, and intensity of human activities in order to determine the factors that influence the emission volume. The results of correlation analysis show that every variable is significant and most of them have a strong correlation coefficient regardless of season.
The variables of naturalness show a negative correlation because slope, altitude, greens, and water limit development or human activities. In the case of land-use, residential, commercial-business, and traffic, there is a positive and strong correlation. Industrial land-use, which is commonly thought to generate much air pollutant emission, shows a weaker correlation than other land-uses.
This is because most industrial zones consist of semi-industries rather than heavy industries, and the total area is much smaller than other land-uses. In addition, a strong positive correlation (0.440 – 0.572) is shown in the population density, building coverage ratio, floor area ratio, and traffic volume and represents the intensity of human activities.