Delhi saw another day of hazardous air quality on Wednesday, with the overall Air Quality Index (AQI) recorded at over 440, categorizing it as ‘severe’ at around 7 am. Several areas of the city reported even worse conditions, entering the ‘severe-plus’ category.
According to the Sameer app, which offers hourly updates on the National Air Quality Index, 21 out of 37 monitoring stations recorded an AQI in the ‘severe-plus’ range on Tuesday morning. Some of the worst-hit stations included Nehru Nagar (480), Alipur (471), Anand Vihar (481), CRRI Mathura Road (468), Jahangirpuri (468), and Rohini (466). The Central Pollution Control Board (CPCB) classifies an AQI of 401-450 as ‘severe,’ while anything above 450 is labeled ‘severe plus.’ The last time Delhi’s AQI reached the ‘severe-plus’ level was in mid-November.
In response to the worsening air quality, authorities reimposed Stage 4 anti-pollution measures under the Graded Response Action Plan (GRAP) on Monday night. These include bans on construction activities and restrictions on the entry of trucks into the city. Experts have attributed the sudden spike in pollution to a significant drop in wind speeds, which allowed local pollutants to accumulate in the atmosphere.
During winter, Delhi implements the GRAP system, which classifies air quality into four stages: Stage I (Poor, AQI 201-300), Stage II (Very Poor, AQI 301-400), Stage III (Severe, AQI 401-450), and Stage IV (Severe Plus, AQI above 450). Under Stage IV, additional measures are also considered, such as limiting office staff to 50%, closing non-essential businesses and colleges, and implementing odd-even vehicle restrictions.
Stage IV was first enforced in Delhi in November, and although the Supreme Court allowed a temporary relaxation in early December after air quality improved, unfavorable weather conditions, combined with emissions from vehicles, stubble burning, and firecrackers, have again led to hazardous pollution levels. Doctors have warned that breathing in Delhi’s polluted air is equivalent to smoking around 10 cigarettes a day.
