The air contains a high quantity of contamination within the normal level is a long time. Can cause hazard to the environment and human beings. What animals or general resources.
Air contaminants that are present in higher than normal levels for a long time. Can cause harm to humans, animals and the environment, objects or resources in general.
The air with additives are higher than the normal level for a long time. Can cause danger to the environment and humans, animals, objects or resources generally.