New Delhi, 8/11: Air quality in Delhi and its suburbs dropped to the severe category again on Wednesday morning, with smoke from post-harvest paddy straw burning in neighbouring states accounting for one-third of the air pollution in the national capital.
The city’s Air Quality Index (AQI) stood at 421, worsening from 395 at 4 pm on Tuesday. Despite a marginal dip, the concentration of PM2.5, fine particulate matter capable of penetrating deep into the respiratory system and triggering health problem.