In evaluating the role and importance of emissions in air pollution, several factors must be considered, as follows:
Type of source: It refers to considerations of natural and man-made sources, as well as to broad classifications and specific examples within each class. The source factor will be discussed in greater detail below.
Number and spatial distribution of sources: Air pollution sources have been be grouped in three major categories:
- Single or point sources: These have been the rather large readily identifiable sources as a power plant, petroleum refinery, and still mill.
- Area- wide or multiple sources: These represent collectively, a large number of smaller sources distributed over a well-defined area. Examples of this have been an entire residential area, or a block of apartments or commercial buildings concentrated in one section of the community.
- Line sources: Freeways, highways and arterials carrying a steady stream of moving vehicles have been contributing line sources of pollution.
Type of emissions: of most direct importance to the problem of air pollution have been the natures and characteristics of the contaminants emitted to the atmosphere. For convenience, all emissions can get segregated into three traditional states- solid, liquid and gaseous.
Characteristics properties of the various airborne contaminants have been important in considering their potential role in air pollution. Among these have been follows:
- Physical properties: Particle size, shape, surface area, density, electric charge, radioactivity. In addition, vapor pressure, temperature and pressure of gaseous substances are important properties, particularly as they may relate to their state while in storage or in stacks.
- Chemical properties: Acidity and alkalinity, solubility hygroscopicity, photochemical reactivity of vapors and corrosiveness.
- Biological properties: Toxicity to human, plant and animal tissue, taste, odor.
Rate of contaminant emission: Air pollution have been a manifestation of a condition in which the rate of introduction of foreign substances in into the ambient air exceeds the self-purification capability of the atmosphere. Thus, consideration of emission rates has been germane to the entire problem. Units of expression in the field of air pollution have been most unconventional and represent outgrowths of a number of professional fields and disciplines which have been historically involved.
Natural air pollution sources:
- Wind blown dust
- Pollen and other aero-allergens
- Sea salt nuclei
- Smoke, fly ash and gases from forest fires
- Microorganism
- Gases and odors from swamps and marshes
- Fog
- Volcanic ash and gases
- Natural radioactivity
- Ozone from lighting and ozonosphere
- Meteorite dust
- Natural Hazes
Man-made sources: The sources of man-made pollution have been covering a wide spectrum of types. The accompanying table includes a classification of major types, categories and examples of air pollution sources and their characteristics pollutant emissions.
2 comments:
Having this kind of environment with full of pollution and disasters was made by nature itself but most of these was made by people. People who abuse our nature which was made by God. Though people start to think of blaming nature and God, why don't they look first at their doings?? Aren't we are the one whose responsible for these disasters? Because of our abuse we are experiencing flash floods, typhoons, earthquakes and etc. That's why I think that if we just put a little concern for our mother earth we might gain peace and receive no more disturbance from the wild nature itself. "What you do is what you get".
Having this kind of environment with full of pollution and disasters was made by nature itself but most of these was made by people. People who abuse our nature which was made by God. Though people start to think of blaming nature and God, why don't they look first at their doings?? Aren't we are the one whose responsible for these disasters? Because of our abuse we are experiencing flash floods, typhoons, earthquakes and etc. That's why I think that if we just put a little concern for our mother earth we might gain peace and receive no more disturbance from the wild nature itself. "What you do is what you get".
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