New Delhi: With a drop in wind speed and the return of fog, the air quality of the national capital turned 'severe' today, following a fairly long period when strong wind movement had helped keep the pollutants at bay.
The air quality index of the Central Pollution Control Board (CPCB) had Delhi's air in the 'severe' category with a reading of 410, which may affect healthy people and seriously impact those with existing respiratory ailments.
Private agency Skymet has forecast that pollution levels are likely to increase "manifold" due to change in wind direction, increase in moisture levels and massive drop in wind speed.
The 24-hour-average (rolling) of ultrafine pollutants PM 2.5 and PM 10 were 182 and 343 micrograms per cubic metre respectively, as against the corresponding safe limits of 60 and 100 respectively.
Cold and dry and northwesterly winds are giving way to easterly winds, which will spike the volume of pollutants in Delhi's air, a senior IMD official explained.
"The entire Indo-Gangetic Plain is under the blanket of fog. In Delhi, the fog may mix with pollutants to turn into smog. The situation will persist for the next two-three days," the official said.
TERI fellow Sumit Sharma said in the absence of stringent emission control measures, air quality is hugely dependent on meteorology.
"Adverse conditions (like very low wind speed) will not allow pollution to disperse and high pollution concentrations are developed," he said.
