Delhi's air quality suddenly improves yet renders pollution masks useless

1. Delhi's air quality suddenly improves yet renders pollution masks useless The overall air quality index (AQI) on Monday was registered in the severe category at 397 against 434 a day earlier.

2. With Diwali just a day away, Delhi's air plummeted to "hazardous levels" but bounced back to "very poor" category on Tuesday, leaving people gasping for fresh air with some wearing pollution masks to reduce the ill effect of bad air quality. Meanwhile, air purifiers have been installed at the ITO crossing in Delhi in view of rising pollution levels in the air. As a thick blanket of haze engulfed the national capital on Monday, experts warned that the air quality is likely to worsen further due to local factors during the festival while doctors said the impact of air pollution on public health can be compared to smoking 15- 20 cigarettes a day. The overall air quality index (AQI) on Monday was registered in the severe category at 397 against 434 a day earlier. The PM2.5 (particles in the air with a diameter of less than 2.5 micrometres) and PM10 concentrations touched 246 and 372 respectively, both in the very poor category, according to SAFAR data. on Monday, the PM10 concentration in several parts of Delhi recorded 'severe plus emergency' levels, around 10 times the permissible limit. The improvement was seen in NCR too as Faridabad, Ghaziabad, Noida and Gurgaon recorded "poor" pollution levels, according to Central Pollution Control Board data. An AQI between 0 and 50 is considered "good", 51 and 100 "satisfactory", 101 and 200 "moderate", 201 and 300 "poor", 301 and 400 "very poor", and 401 and 500 "severe". According to a warning issued by the Centre-run System of Air Quality Forecasting and Research (SAFAR), the national capital's air quality is expected to deteriorate to 'severe plus emergency' category after Diwali and it will be "bad" on November 8 even if "partial toxic crackers" are burned compared to last year. Business Standard