Strong wind helps disperse pollutants

A day after spiralling to alarming levels, pollutants in Delhi's air reduced considerably as strong wind considerably dispersed suspended particulate matters, PM 2.5 and PM 10, prompting authorities to forecast a relatively cleaner Christmas Day.
The average level of PM 2.5, tiny particles that can embed themselves deep in the lungs and enter the bloodstream, dropped to 200 micrograms per cubic metre, that falls in the 'poor category', as opposed to yesterday's 295.
Scientist Gufran Beig of System of Air Quality and Weather Forecasting and Research (SAFAR) told PTI that wind speed increased by up to three times and swept away the pollutants and a drop in humidity only aided the clean up.

Beig explained that one of the reasons behind yesterday's jump was 'secondary aerosol formation', wherein particles mix with water molecules of fog, thus "multiplying" the amount of pollutants.
Even that phenomenon has ceased, the Chief Project scientist of SAFAR said while adding that the situation would be relatively better tomorrow and the day after.
Although there is a likelihood of increase from December 27 onwards due to westerly disturbances, Beig said.

Meanwhile, Central Pollution Control Board's national air quality index could not be accessed as most of its stations continued to display figures of December 23. Anand Vihar's AQI was 'severe', with the most prominent pollutant being PM 10.

Yesterday was the most polluted day of the year in Delhi with the average of PM 2.5 and PM 10 at 295 and 470 micrograms per cubic metre respectively, a rise attributed mainly to influx of pollutants from the Indo-Gangetic plains region arising out of biomass burning.
According to Indian authorities, the safe limits of PM 2.5 and PM 10 are 60 and 100 micrograms per cubic metre respectively while World Health Organisation considers 25 to be the maximum safe level of PM 2.5.