NEW DELHI: Smog is toxic Hung over the city on Friday and other stations recorded the air quality ‘severe’, although the overall Air Quality Index of the capital remained at the level above the ‘very poor’ zone. The smog that formed in the morning remained until the afternoon due to calm wind conditions and the pollution continued to increase as the day passed.
The average AQI of the city is 373 during the day and becomes 380 at 3 pm and 386 at 6 pm. For Delhiites, it’s another November air nightmare with many complaining of itchy eyes, light-headedness and difficulty breathing as pollution levels continue to rise, with possible spikes in NO2 and ozone, experts said.
In the morning, a total of eight areas of the city were in the “severe” category, with Anand Vihar, with an AQI of 425, the most polluted, followed by Vivek Vihar with 424.
In the evening, the number of stations reporting ‘severe’ weather increased to 11, and to 16 by 7pm. At 7 pm, Anand Vihar was the most polluted area in the city with an AQI of 442, followed by 435 in East Delhi’s Vivek Vihar. Other polluted areas include Alipur, Nehru Nagar in South Delhi, Sector-8 Dwarka, Bawana, Jahangirpuri, and Wazirpur, among others.
The city’s average AQI, on a scale of 0 to 500, was 381 on Monday against 382 the previous day. PM2.5 levels oscillated between 171.8 and 180.7 micrograms per cubic meter on Monday, against the national safe standard of 60 units and 15 WHO units in 24 hours.
“Smog weather is really smog because many areas are at a heavy or very high level. Small pollutants such as PM2.5 in the air can settle deep in the lungs, causing serious health problems. During this time, when the pollution level is increasing, people those with pre-existing health conditions are more susceptible to respiratory distress,” said Shambhavi Shukla, program manager, Air Quality Programme, Center for Science and Environment (CSE). Experts also say that the decrease in temperature and low wind speed increase pollution.
“Decreasing temperature and wind speed lead to stagnation of pollution, while lower mixing depth affects pollution near the surface. This pollution mixes with fog, forming smog, which reduces visibility and leads to the gray sky we see today,” said Sunil Dahiya, Founder and Principal Analyst, Envirocatalysts.
According to the air quality early warning system, the city could see poor air quality for the next two days, after which the AQI could worsen. He added that the low wind speed over the next few days would not allow for the spread of pollutants. “Meteorological conditions may not be favorable for the spread of pollutants … Air quality may be in the very poor category on November 4. Air quality will remain poor from November 5 to 7. The following six days: Air quality may be in the category of very bad to severe,” said IITM’s air quality early warning system bulletin.
According to IITM’s Decision Support System (DSS), the contribution of farm fires to the city’s PM2.5 level increased to 19.7% on Monday against 15% the previous day. However, experts also point to the role played by smog, sunlight and vehicle emissions in increasing pollution levels.
“Ozone is formed when nitrogen dioxide (NO2) reacts with volatile organic compounds (VOCs) in sunlight. Burning fossil fuels releases particulate matter and NO2, while burning stubble raises pollution levels as well, also emitting high VOC levels, fueling high ozone formation .the temperature increases during the day, the ozone concentration increases, as shown in the monitoring data in Delhi NCR,” said Dahiya.
The city recorded a maximum temperature of 32.1 degrees Celsius, two levels below normal, against 33.2 degrees Celsius a day earlier. The minimum temperature was recorded at 16.6 degrees C, a notch above normal, against 16.5 degrees C the previous day. The maximum and minimum temperatures on Tuesday are likely to be around 32 and 16 degrees Celsius respectively.
Meanwhile, Gurgaon on Monday recorded the most polluted 24 hours of the season, with air quality dropping to ‘very poor’ as cold weather conditions and calm winds failed to clear the toxic haze. Gurgaon’s 24-hour average AQI touched 310 on Monday, a 10% increase from 281 (poor) the previous day.
