Smog in Capital on Friday morning as air quality plummets again
Data from the Hindustan Times air quality map showed that air quality index (AQI) was touching the maximum limit of 500 at many places like Anand Vihar, Punjabi Bagh and RK Puram. AQI is an index to define the air quality which tells us how clean or polluted the air is.delhi Updated: Oct 28, 2016 12:51 IST
Friday morning in Delhi was slightly chilly and pleasant, with minimum temperature settling at 16.1 degrees Celsius, normal for this time of year. However, the ominous sign of smog-like mist in the air showed that this was just another bad day in terms of the air we breathe in the capital.
Data from the Hindustan Times air quality map showed that the air quality index (AQI) in the city touched the maximum limit of 500 at many places including Anand Vihar, Punjabi Bagh and RK Puram.
The AQI is an index to define the air quality which tells us how clean or polluted the air is. It considers eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb). Based on the measured ambient concentrations of these pollutants, a sub-index is calculated for each of these and the worst sub-index reflects the overall AQI.
The Ugly (500)
On 10 am on Friday, Anand Vihar, arguably the most polluted spot in the city, had the foulest air.
PM10 reached 845µg/m³ while PM2.5 touched 325µg/m³. The permissible level of PM 10 is 100 micrograms per cubic metre. It is 60 micrograms per cubic metre for PM2.5.
At RK Puram, PM2.5 reached as much as 449µg/m³. Similarly, at Punjabi Bagh, PM10 touched 688µg/m³ while PM2.5 clocked 314µg/m³.
The really bad: Severe (400-500)
At Mandir Marg, the AQI was 424. PM 10 clocked 449µg/m³ while PM 2.5 reached 253µg/m³. Similarly at Shanti Path the AQI reached 441 with PM2.5 levels touching 302.9µg/m³.
Pollution level is classified as severe if the AQI ranges from 401 to 500. Such a situation is called “red alert” in China. When it continues for three consecutive days, it calls for desperate measures like shutting down schools and offices, closing down industries and power plants and start road rationing of vehicles.
The bad: Very Poor (300-400)
When air quality is “very poor” in terms of AQI, people are advised to avoid outdoor activity, especially the elderly and young children, and use anti-pollution masks. At Shadipur, the AQI reached 394 with PM2.5: recording at 242.77µg/m³. At Netaji Subhas Institute of Technology, it was 350 with PM2.5 levels touching 185.4 µg/m³
The good: Satisfactory (50-100)
At some corners of the city, however, things were much better. Monitoring at Lodhi Colony showed an AQI of 55 with PM 10 clocking 55.03 µg/m³ and PM2.5 reaching 27.9 µg/m³. At Adchini, it was 70 with PM10 clocking 55.57 µg/m³ while PM2.5 touching 42.12 µg/m³.
The best: Good (0-50)
At CR Park, the AQI on Friday morning was 44. PM10 reached just 44.08 µg/m³ while PM 2.5 touched 8.24 µg/m³.
Why this pollution in the city?
The dip in air quality has been primarily attributed to an increase in vehicular traffic in the festival season, decreasing temperatures and lack of winds. Low wind speed settles pollution particles on the surface instead of blowing them away.
The situation will worsen in next few days as more vehicles are expected to be on the road for Diwali -- pollution levels usually jump by almost five times as revelers burst millions of firecrackers.
“Ambient air is influenced heavily by activities such as agriculture burning, industrial emission, operation of more than 4,000 brick kilns and massive ongoing construction activities. Major farm fires have been recently reported in Punjab and Haryana. Delhi being on down-wind direction has been impacted severely and the city may face critically polluted period during the coming days,” an environment department official had said on Thursday.
Weather on Friday
According to a MeT department official, the skies are expected to remain clear during the day after the early morning mist and the ensuing fog.
The maximum temperature is likely to hover around 32 degrees Celsius, the official said. On Thursday, the maximum and minimum temperatures were recorded at 32.3 degrees Celsius and 16.5 degrees Celsius respectively.
Check the air quality in your locality using Hindustan Times’ Air Quality Index tool below.
First Published: Oct 28, 2016 12:31 IST