_Environmental pollution is the change of environmental components not in accordance with environmental technical regulations and environmental standards, and adversely affects humans and organisms (Clause 8, Article 3 of the Law on Environmental Protection. school year 2014).
The variation in environmental components can be caused by many reasons, of which the main cause is contaminants. Contaminants are defined by scientists as physical substances or factors that, when present in the environment, pollute the environment. Normally pollutants are wastes, however, they can also appear as raw materials, finished products, scrap, by-products ... and are classified into the following categories:
Accumulated pollutants (plastics, radioactive waste) and non-cumulative pollutants (noise);
+ Local pollutants (noise), regional (acid rain) and globally (CFC);
+ Pollutants from identifiable sources (wastes from production and business establishments) and unidentifiable pollutants (chemicals used for agriculture);
+ Pollutants caused by continuous emissions (Waste from production and business establishments) and pollutants caused by discontinuous emissions (oil spills due to oil spills).
