On Saturday at some areas in Delhi, the concentrations of Particulate Matter or PM 10 (coarser pollutants) was over 1,200 micrograms per cubic metre compared to a safe level of 100 and PM 2.5, a standard measure of air quality, was as much as 13 times the safe limit. Thus the national capital of India was really grappling with some of the worst pollution in recent years. So, having no other alternative, it was decided to keep the municipal schools shut on Saturday because of smog in Delhi. The schools will, however, operate as normal from Monday.