The fitness enthusiasts remained undeterred by thick smog which has engulfed Delhi and continued their exercise routine in Rajpath area. Almost all of them could be seen wearing masks. Exposure to smog can be severely harmful to the health of the exposed as it can cause/aggravate health conditions such as chest infections, asthma, cold and eye irritation. On Friday morning, Delhi woke up to yet another foggy morning with extremely poor visibility levels. The Air Quality Index across the city remained in the "hazardous" category. In Mandir Marg it was 515, in Punjabi Bagh it stood at 802, Anand Vihar was at 571 while in Dwarka it was 420. An analysis of the Central Pollution Control Board's AQI bulletin archives has shown that air quality has become worse across the northern-Gangetic region in places such as Lucknow, Agra, Kanpur and Muzzafarpur.