Air quality remains foul in Delhi, expect worse on Diwalidelhi Updated: Oct 29, 2016 21:06 IST
Early morning smog in Delhi on Saturday, October 29.(Saumya Khandelwal/Hindustan Times)
A day before Diwali, Delhi woke up to a foggy morning on Saturday which stayed hazy for the rest of the day due to high levels of pollution.
Data from the Hindustan Times air quality map showed that the AQI (air quality index) had peaked -- touching the maximum limit of 500 -- in areas such as Anand Vihar, Punjabi Bagh and Shadipur.
Air pollution level is classified as severe if the AQI is between 401 and 500. China declares a ‘red alert’ if air quality plunges to this level. If the alarming levels continue for three consecutive days, China facilitates measures such as shutting down schools and offices, closing industries and power plants and road rationing of vehicles.
Anand Vihar was possibly the most polluted area in Delhi at 10am on Saturday morning, as particulate matter levels (PM10 was 552µg/m³ and PM2.5 -- 443µg/m³) soared. Later in the day, at noon, PM 10 (coarser pollutants) levels reached nine times above the safe limit in real-time at 913 micrograms per cubic meter.
PM10 and PM2.5 are minute particulates that penetrate the lungs and cause breathing ailments. The permissible level of PM10 is 100 micrograms/cubic metre and 60 for PM2.5.
Punjabi Bagh (494µg/m³) and Shadipur (571µg/m³) recorded high levels of PM2.5. Air quality levels plunged in other areas such as Mandir Marg (484) and Shanti Path (408) on Saturday.
The dip in the air quality was primarily due to an increase in traffic due to Diwali, decreasing temperatures and a lack of winds. Low wind speed helps pollution particles settle on the surface instead of blowing them away.
The System of Air Quality and weather Forecasting and Research (SAFAR) put the average volume (24-hour rolling) of PM 2.5 and PM 10 at 226 and 425 micrograms per cubic meter respectively in the afternoon. PM 2.5, finer and deadlier, was the most prominent pollutant in monitoring stations of Central Pollution Control Board (CPCB) such as Punjabi Bagh, RK Puram, Anand Vihar and Shadipur located across the city.
According to SAFAR’s special Diwali forecast, pollution during this year’s Diwali is expected to be worse than 2014 and 2015 due to a combination of adverse meteorological factors like slow wind speed and moisture in the air, a major hindrance in the dispersion of suspended pollutants.
SAFAR has advised people to avoid all outdoor physical activity. People with heart or lung disease, older adults, and children should remain indoors and keep activity levels low when air quality turns “severe”, it said. People with existing heart or lung diseases such as asthma, congestive heart disease, or ischemic heart disease should avoid prolonged or heavy exertion when the air quality is “very poor”.
The maximum temperature on Saturday was recorded at 32.5 degrees Celsius, a notch above normal, while the minimum settled at 15 degrees Celsius, a notch below normal. Humidity levels oscillated between 94 and 47%.
The weathermen predicted mist in the morning on Sunday while the sky will be clear for the rest of the day. The minimum and maximum temperature is expected to hover around 15 and 31 degrees Celsius.
First Published: Oct 29, 2016 21:06 IST