LOW TEMPERATURE and almost no wind over the weekend resulted in very poor air quality and haze throughout the day on Sunday. The air quality index for the city read 365 (out of a maximum of 500), indicating “very poor” air quality. It was slightly worse than Saturday’s index, which read 331, also “very poor”.
According to the air quality forecast by the Ministry of Earth Sciences-headed System of Air Quality and Weather Forecasting and Research (SAFAR), Monday and Tuesday are expected to be worse.
The average PM 2.5 concentration in the city was 189 micrograms per cubic metre on Sunday evening. The SAFAR forecast says it will be around 204 micrograms per cubic metre on Monday, and 213 micrograms per cubic metre on Tuesday.
The acceptable concentration for PM 2.5 is 60 micrograms per cubic metre.
Officials at the India Meteorological Department (IMD) said winds were calm between 8.30 am and 2.30 pm on Sunday. The winds picked up a little speed towards the evening but could go only up to 6 km per hour, which is not enough to disperse pollutants.
“Almost no wind for two consecutive days coupled with dipping temperatures have resulted in a concentration of particulate matter. The situation had improved for two days last week because of mild winds, but that effect lasted only for a short while,” said a senior IMD official.
The minimum temperature on Sunday morning was 8 degrees Celsius, a degree below normal. The maximum was 26.4 degrees Celsius, a degree above normal.
The Central Pollution Control Board (CPCB) advisory says that exposure to very poor air quality for a prolonged period can cause respiratory illnesses. It also causes breathing discomfort and affects those with asthma and bronchitis in the short run.