The ‘milky white’ nature of fog and associated haze that has shrouded Delhi at the onset of winter shows that pollution has not yet spiked to last year’s level, a top expert has said, indicating that the worst is yet to come.
The city’s air quality, that “became better” post Diwali and then fell on November 26, has largely oscillated between ‘very poor’ and ‘poor’, with pockets where it is ‘severe’, said Gufran Beig, chief project scientist of System of Air Quality and Weather Forecasting And Research (SAFAR) .
“Levels of PM 2.5 touched 130 micrograms per cubic metre on November 17 but thereafter, it again started increasing and reached 220. For the last week or so it is hovering in the range of 160-190,” Beig said.
‘Very poor’ signifies PM 10 and PM 2.5 levels between 351 and 420, and 211 to 252 micro gram per cubic metre, respectively. ‘Severe’ is declared when PM 2.5 and PM 10 cross 253, 421 micro gram per cubic metres respectively.
“There are two differences with last year. This time wind movement is not that calm and temperature also not very cold, hence the pollutants did not get accumulated. So what we have until now is a milky white fog,” he said.
Beig said that apart from PM 2.5, PM 10, carbon monoxide (CO) has gone above the threshold limit at times in the capital.