Limitations of Air Quality Index exposed

Delhi’s struggle with air pollution continues even after the introduction of the Air Quality Index (AQI). The AQI failed to record pollution levels in almost half of the 28 locations, which it is supposed to monitor. The reason being lack of sufficient data on air pollution. As a result, data for some of the most highly polluted areas in the capital like ITO and Shahdara, was not available.

Moreover, in other locations, the index indicated ‘moderate’ air quality levels while real-time monitoring from the Central Pollution Control Board (CPCB) and the Delhi Pollution Control Committee (DPCC) showed high level of toxicity in the air.

AQI categorizes air quality into six different levels. These are, good, satisfactory, moderate, poor, very poor, and severe. The index uses a 24-hour average of three highest pollutants to categorize air quality. Out of 11 locations, the index failed to monitor air quality in five.

Even though the level of particulate matter (PM) was high in certain areas, the index showed that the air quality was moderate. High level of particulate matter (PM) often leads to serious breathing ailments. In Delhi’s Anand Vihar, the minutest particulate level (PM 2.5) rose to 438 micrograms in one cubic meter air.

Low presence of other air pollutants like Sulphur dioxide and nitrogen dioxide has dragged the average down. In addition to this, the index also failed to provide data in Agra, Ahmedabad, Faridabad, and Hyderabad. Only limited amount of data was generated in Bengaluru, Chennai, and Lucknow. Even in Modi’s constituency of Varanasi, air quality has been ranked ‘poor’ on a consistent basis.