India's Central Pollution Control Board (CPCB) reported Delhi's Air Quality Index (AQI) at 299 on Nov. 10, the highest among six cities and the only reading in the board's “Poor” category.
Mumbai and Chennai each recorded 148, while Bengaluru was at 140 and Kolkata at 129. All four cities were in CPCB's “Moderate” category. Hyderabad registered 94, the lowest of the six and the only “Satisfactory” reading in the comparison.
CPCB's national scale defines 201 to 300 as “Poor,” 101 to 200 as “Moderate” and 51 to 100 as “Satisfactory.” The board says prolonged exposure to air in the “Poor” range may cause breathing discomfort. Its guidance also identifies people with lung or heart disease, children and older adults as groups who may experience breathing discomfort in the “Moderate” range.
The Nov. 10 bulletin summarizes the 24 hours ending at 5:30 a.m. ET (10:30 UTC). Delhi's figure used readings from 58 of 59 monitoring stations. CPCB listed PM10 and PM2.5 as the city's prominent pollutants.
