The nature and effects of air pollutants, including:

• Oxides such as: nitrogen oxides (NO, NO2), nitrogen dioxide (NO2), SO2, CO, H2S and other gaseous halogen (chlorine, bromine, iodine).
• Fluorine compounds.
• The synthetic (ether, benzene).
• Solids suspended particles (dust, loose dirt, dust, micro-organisms), nitrate, sulfate, carbon molecules, aerosols, soot, smoke, fog, pollen.
• Heavy dust, dirt, rocks, dust, metals such as copper, lead, iron, zinc, nickel, tin, cadmium, etc.
• Photochemical air as ozone, FAN, FB2N, NOX, aldehydes, ethylene ...
• Radioactive waste.
• Temperature.
• Noise.

Six agents pollution generated mainly due to fuel combustion and industrial production. Air pollution agents can be classified into two types: vapor gases and small particles. However, most of the polluting agents are harmful to human health.

Pollution agents are divided into two categories: primary and secondary. Sulfur dioxide produced by burning coal which is the primary pollution. It impacts directly to the receiving department. Then, the gas associated with oxygen and water of clean air to form sulfuric acid (H2SO4) fall to the ground with the rain, changing the pH of the soil and water bodies, negatively impact many plants , animals and microorganisms. Thus, acid rain have been the secondary pollutants formed by the combination of SO2 with water. In some cases, non-polluting agents, the optical link together to form new secondary pollution agents, adverse impacts. Organism response to pollution agent dependent on the concentration of pollutants and their effects.