While the rains in the last few days had brought down the pollution level in the city, the foggy condition has again increased the pollution in the city, said pollution control board officials.
The Air Quality in Index in city had reached ‘Poor’ category as it was hovering above 200 about a week ago but due to rainfall for four consecutive days, it dropped below 100 which falls in ‘Satisfactory’ category.
Not only AQI, PM10 and PM 2.5 had also reached 'very poor' level and recorded maximum at 414 and 363 micrograms per cubic meter, respectively about a week ago.
“Indeed, the level of pollution has decreased due to rainfall in the city. However, the AQI was fluctuating due to the fog in the weather,” Chief Chemist of Pollution Control Board Dr DK Waghela said.
He added that after dropping below 100, the AQI again increased over 150 in Tuesday evening due to the fog which pulled the pollutants close to the ground.
“It is a temporary fluctuation as the air would get cleaner after wind starts blowing and the sky clears,” Dr Waghela added.
Average AQI on Dec 11 was 99, on Dec 12 was 97, 88 and 89 on December 13 and December 14.
The level increased on Tuesday as AQI was recorded 194 at 5 pm.
No relief from overcast weather
Citizens got no relief from the overcast weather for the fourth consecutive day on Tuesday. The entire morning remained foggy and there was no sunshine throughout the day.
Cold winds also kept the day temperature five degrees Celsius below the normal and the same phenomenon kept the night temperature five degrees Celsius above the normal.
Level of humidity was 94 per cent in morning and 93 per cent in evening.