_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).

Although there are many different factors to these complex (complicated with many parts) problems, I will talk about a few. I would say that the cause of these pollutions are due to industry, such as the factories. Moreover, farming contributes to this problem, as there is a high demand to have enough food for the increasing population. Lastly, water pollution stems from (starts from) poor waste management systems in rural areas, as well as ineffective operation of waste treatment facilities.