New Delhi, Jan. 21 -- The Commission for Air Quality Management (CAQM) on Tuesday lifted Stage-4 of the Graded Response Action Plan (Grap) after the air quality improved marginally. The 24-hour average air quality index (AQI) stood at 378 (very poor) at 4 pm - down from a reading of 410 (severe) at 4 pm on Monday, snapping a three-day streak where the AQI was 400 or higher. P7...