Kolkata's air quality has significantly improved with the dip in the number of vehicles plying on the roads due to restrictions imposed two days ago to check the spread of coronavirus, an official of West Bengal Pollution Control Board said on Friday.
There is far lesser emission of sulphur, nitrogen, carbon particulates in the air as number of vehicles have dwindled while commercial activities have come down significantly resulting in less air pollution, he said.
Environmentalist S.M. Ghosh said this is good for both Covid-19 patients and others having respiratory problem.
The air quality index (AQI) in the city was between 39 to 63 pm 2.5 in all but one air station in the city at 6 pm, the official said.
Only in Rabindra Bharati University air monitoring station next to arterial B T Road the air quality index was 95, that too within 100 mark or satisfactory level (51 to 100 AQI), he said.
At Ballygunje AQI level was 63, at Bidhannagar 51, at Fort William 60 and at Rabindra Sarobar 56.
At Jadavpur it was 39, marked as good.
The AQI hovered between 201 to 250 AQI in February- March (classified as poor ) in several air monitoring stations during early evening hours in February and got down to 101-200 (moderate level) since April gradually coming to the satisfactory level in end April, he said.
Satisfactory AQI in environment parlance means minor breathing problem to sensitive people, moderate labeling means breathing problem to people with respiratory problem and heart diseases and poor tag means breathing problem to most on prolonged exposure, he added.
Mr. Ghosh said in the past two days only 30 micrograms per cubic meter was recorded (pm 2.5 or 2,5 micron size) in the open, while the level of respirable particulate matter in a room on the side of a main road is only 8 mg/cubic meter.
