The environment

Pollution can be classified according to different criteria, in particular those based on the nature of the polluting agent; ecological considerations and purely toxicological considerations.

I. Classification according to the nature of the polluting agent

Depending on the nature of the polluting agent, we distinguish:

1. Physical pollution: this is a type of pollution based on physical factors such as ionizing radiation, artificial heating of the ambient environment caused by a technological heat source.
2. Chemical pollution: this type of pollution is produced by mineral, organic, abiotic or even biochemical substances.
3.  Biological pollution: it is caused by pathogenic microorganisms or by invasive exotic species artificially introduced by humans.

II. The purely ecological point of view: it takes into consideration the environment (air, water, soil), or the part of the biosphere where pollution takes place (atmosphere, hydrosphere, pedosphere), as well as the biocenoses in which they cause disturbances.

III. The toxicological point of view: is based on the environment or the organism’s contamination mode by pollutants. Depending on the contamination mode, in plants, we distinguish between contamination by stomatal absorption, transfoliar contamination and pollution by root translocation.