Air pollution generally happens when there are dangerous and extra quantity of substances which includes gases, particulate matter, and biological molecules are inserted into atmosphere of Earth. This can cause complex and severe diseases to humans; it may also cause harm and damage to other living organisms and food crops, and may destroy the natural and built ecology and environment. Human activities and natural processes both can generate air pollution to a great extent. Unfortunately, India is among those countries with maximum number of most polluted cities in the world with one of the worst Air Quality Index (AQI) especially, on the festival of Diwali; the air quality index of Delhi and NCR has reached to a new higher levels . Lately, the air pollution in Delhi and NCR has gone through many changes in terms of the level of pollutants and the control measures taken to control it.

Keywords : Delhi NCR, Air Pollution, Air Quality Index (AQI).