Chennai air quality index exceeds 1,200 on Deepavali night
Private air quality monitoring platforms reported high pollution levels due to firecracker smoke, while official readings remained in the moderate category.
Private air quality monitors recorded an Air Quality Index (AQI) of over 1,200 in Chennai on Deepavali night, according to The Hindu. The spike in pollution levels was attributed to firecracker smoke during the evening.
The Delhi-based monitoring platform AQI India reported the sharp increase on its dashboard. In contrast, the Central Pollution Control Board (CPCB) showed an AQI value around 200, placing the air quality in the moderate category.
Weather blogger K. Srikanth, who runs Chennaiyil Oru Mazhai Kaalam, stated that an outdoor sensor at his residence recorded an AQI of approximately 1,000 between 6 p.m. and 10 p.m. on Sunday. He noted that the AQI had decreased to around 200 by 7 a.m. on Monday.
Environmental policy researcher Dharmesh Shah said that while private monitors provide an idea of pollution, they cannot be fully accurate. He suggested that Chennai needs a wider network of low-cost air quality monitors.
Official sources explained that the discrepancy in readings occurs because different methods are used to calculate AQI. The official Indian index caps readings at 500 and factors in seven pollutants, whereas some private platforms use the US method based on PM2.5 with no upper limit.
Pollution levels may remain elevated for a few days if northerly winds persist, according to Srikanth. A shift to easterly winds is expected to help disperse pollutants and improve air quality.