New Delhi, Nov 4 (PTI) A layer of pungent haze shrouded the national capital and smudged landmarks from view on Wednesday, as people complained of itchy throat and watery eyes.
Unfavourable meteorological conditions -- calm winds and low temperatures -- caused the air quality to be in the 'severe' category.
According to Central Pollution Control Board (CPCB) data, PM10 levels in Delhi-NCR stood at 448 microgram per cubic meter (µg/m3) at 7 pm, the highest in this season so far. PM10 level below 100 µg/m3 are considered safe in India.
PM10 is a particulate matter with a diameter of 10 micrometers and can get into the lungs. These particles include dust, pollen and mold spores.
The levels of PM2.5 -- finer particles which can even enter the bloodstream -- were 242 µg/m3. PM2.5 levels up to 60 µg/m3 are considered safe.
'It is not even Diwali yet and the city has already become a gas chamber. This happens every year. For how long will this continue?' asked Shiv Shrivastava, a resident of south Delhi.
As the skies hung heavy and acrid over the national capital, the visibility reduced to merely 600 metres at the Safdarjung Observatory. It was 800 metres at the Palam weather station.
According to the India Meteorological Department (IMD), the maximum wind speed was 5 kilometres per hour and the minimum temperature 10.6 degrees Celsius. Calm winds and low temperatures trap pollutants close to the ground, while favourable wind speed helps in their dispersion.
Health experts said that during the COVID-19 pandemic, air pollution has become a serious health concern for about the two crore residents of the national capital.
'I can feel the pollutants in my throat despite wearing a mask. My eyes are burning. It is going to make the pandemic worse. I am scared,' said Piyush Vohra, a resident of Jangpura.
According to a doctor at the Sir Ganga Ram Hospital, intake of every 22 micrograms per cubic metre of polluted air is equivalent to smoking a cigarette. Ajit Jain, the nodal officer for COVID-19 at Rajiv Gandhi Super Specialty Hospital, said air pollution was turning the pandemic catastrophic.
IMD officials said the situation is likely to worsen as similar weather conditions are expected over the next two days.
'The wind speed slowed down suddenly after 10 am in the Delhi-NCR region due to an anti-cyclone. The temperatures have dipped alarmingly over the last few days. Unfavourable meteorological conditions trapped pollutants, resulting in a haze,' V K Soni, a senior IMD scientist, said.
Delhi recorded an Air Quality Index (AQI) of 279 at 10 am. It worsened to 386 by 7:30 pm. Several monitoring stations, including the ones at Narela (461), Wazirpur (445), Bawana (452), Jahangirpuri (454) and Rohini (444), recorded the air quality in the 'severe' category.
The neighbouring cities of Ghaziabad and Greater Noida also recorded 'severe' levels of air pollution.
An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.
However, the Ministry of Earth Sciences' air quality monitor SAFAR said the share of stubble burning in Delhi's pollution was just five per cent on Wednesday. It was 10 per cent on Tuesday.
Stubble burning accounted for 16 per cent of Delhi's pollution on Monday and 40 per cent on Sunday, the maximum so far this season.
Last year, the farm fire contribution to Delhi's pollution had peaked to 44 per cent on November 1, according to SAFAR data. PTI GVS NSD