Air pollution levels in the nation's capital Delhi are always high. The capital city is always exposed to pollution due to industries, automobile fumes and other construction related activities. The winter situation is no more. Obviously, objects can be seen from a distance of 100 meters, except for a dense fog at 8 and 9 am. Motorists are having a hard time finding the roads in November and December. Air pollution in Delhi dropped significantly between March 22 and May 18 due to the lockdown. Air pollution levels in Delhi have declined by 79 per cent, the Center for Science and Environment (CSE) said today. The closure of industries, vehicle traffic, and construction halt are the reasons for the reduction in pollution, CSE said. However, pollution levels have risen again in Delhi and some other major cities, with further deregulation of vehicle traffic and construction on Lockdown after May 18. The Center for Science and Environment (CSE) has studied PM 2.5 (air pollutant)