CIVIL ENGINEERING DEPARTMENT
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1.1. Introduction
Presence of matter (gas, liquid, solid) or energy (heat, noise, radiation) whose nature,
location, or quantity directly or indirectly alters characteristics or processes of any part
of the environment, and causes (or has the potential to cause) damage to the
condition, health, safety, or welfare of animals, humans, plants, or property.
Pollution is the introduction of contaminants into an environment that causes instability,
disorder, harm or discomfort to the ecosystem i.e. physical systems or living
organisms. Pollution can take the form of chemical substances, or energy, such as
noise, heat, or light energy. Pollutants, the elements of pollution, can be foreign
substances or energies, or naturally occurring; when naturally occurring, they are
considered contaminants when they exceed natural levels. Pollution is often classed as
point source or nonpoint source pollution.
1.2. Air Pollution
Air pollution occurs when gases, dust particles, fumes (or smoke) or odour are
introduced into the atmosphere in a way that makes it harmful to humans, animals and
plant. This is because the air becomes dirty (contaminated or unclean).
Anything additional gas, particles or odours that are introduced into the air (either by
nature or human activity) to destroy this natural balance can be called air pollution.
Things that pollute the air are called pollutants. Examples of pollutants include nitrogen
oxides, carbon monoxides, hydrocarbons, sulphur oxides (usually from factories), sand
or dust particles, and organic compounds that can evaporate and enter the
atmosphere. When pollution occurs in the air, it can easily travel and spread, and
because we breathe in air, we cannot easily avoid it. There are two types of pollutants: