Environment experts say Khanna has been notorious for high air pollution levels for quite a long time now. "Khanna has been one of the hotspots of air pollution, and has been showing high levels for quite some time now. The normal value for air pollution levels is around 100ppm, but if the value is more than 120 ppm, then there is a problem. The Punjab Pollution Control Board or the Central Pollution Control Board (CPCB) can make a local assessment of pollution sources, and frame an action plan to control the problem," said Anumita Roy Chowdhury, executive director, Research and Advocacy wing of the Centre for Science and Environment (CSE).

Local doctors say air pollution is badly affecting the health of city residents. "Around four years ago, we would get just 5 -6 cases of respiratory ailments, including asthma and other allergic respiratory diseases at our hospital, but now the number is around 8 -10 a day. Shockingly, the patients also include children," said Dr Amarbir Singh, a reputed physician, who runs a private hospital in the city. PPCB authorities say the drop in pollution levels is a welcome change.