India, Nov. 21 -- Delhi's air quality deteriorated further with several areas falling below the 'severe' mark on Friday, with mounting medical alarms and surveys showing that nearly 80 per cent households in Delhi-NCR have had at least one member fall ill due to toxic air in the past month.

Calling this a 'public health emergency', experts have said that there is enough evidence to show that pollution hits life expectancy. Doctors also said that while masks and air purifiers offer certain protection, a round-the-year policy change is needed to tackle the problem.

2. 18 stations cross 'Severe': Over 18 monitoring stations logged AQI above 400. These include Chandni Chowk, Anand Vihar, Mundka, Bawana, Narela, DTU and Wazirpur - many of wh...