For the first time since Diwali, Delhiites woke up to improved air quality on Saturday, with levels of harmful pollutants coming down from the hazardous levels observed in the beginning of November to moderate or simply poor. This was thanks to wind picking up and warm day temperatures.
Starting from Diwali on October 30, the National Capital Region saw air pollution peak to toxic levels, with one of the worst smog episodes in decades being recorded in the first week of November. Concentration levels of particulate matter had reached 14 to 17 times the safe limits.
On Saturday, however, the level of the fine PM2.5, which is dangerous as the particles are small enough to get lodged in the lungs, fell below 60 micrograms per cubic metre -- the standard -- at some places in Delhi. According to the Delhi Pollution Control Committee (DPCC), the hourly PM2.5 concentration at Anand Vihar, usually the most polluted part of the city, fell to 68 micrograms per cubic metre, or almost the safe level at 2 p.m.
“In fact, the level of PM2.5 was so low compared to the weekly average that at Mandir Marg monitoring station that auto-calibration was thrown off for a bit,” said a DPCC official.
This improvement was down to not only winds of up to 14km/hr on Friday night, but also the vertical movement of wind that dispersed pollutants.
However, the 24-hour average of PM2.5 as of Saturday evening was 109 micrograms per cubic metre, or almost double the safe level and in the ‘poor’ category, as per the Union Earth Science Ministry’s System of Air Quality and Weather Forecasting Research (SAFAR). The level of PM10 was relatively better, with 234 micrograms per cubic metre or just over double the safe level of 100. This put it in the ‘moderate’ category, a first since Diwali.
The levels of pollution are expected to decrease even more by Monday, with the level of PM2.6 expected to dip below 100 micrograms per cubic metre.
