Delhi air quality nears emergency threshold, primary schools closed

New Delhi: Delhi-NCR's air quality neared the emergency threshold on Thursday, prompting an immediate ban on non-essential construction work and the closure of primary schools in the capital, as authorities acted swiftly to address the health-threatening pollution.

As a dense and pungent haze blanketed the skyline of Delhi-NCR, the concentration of PM2.5, fine particulate matter that can penetrate deep into the respiratory system and trigger health problems, exceeded the safe limit of 60 micrograms per cubic metre by a seven to eightfold at multiple locations throughout the region.

According to a numerical model-based system developed by the Indian Institute of Tropical Meteorology in Pune, smoke from stubble burning accounted for 25 per cent of the PM2.5 pollution in Delhi on Thursday. It may soar to 35 per cent on Friday.

Alarmed by the spike in air pollution levels, the Centre's pollution control panel ordered an immediate ban on non-essential construction work, stone crushing and mining in the region.

Restrictions have also been imposed on plying of BS III petrol and BS IV diesel four-wheelers in Delhi, Gurugram, Faridabad, Ghaziabad and Gautam Budh Nagar.

Delhi Chief Minister Arvind Kejriwal announced that all government and private primary schools in the city will remain closed for the next two days in view of rising pollution levels.

Delhi Environment Minister Gopal Rai has called an emergency meeting on Friday to review the situation.

The Centre's action comes as part of Stage III of the Graded Response Action Plan (GRAP) -- the Centre's air pollution control plan which is implemented in the region during the winter season.

GRAP categorises actions into four stages: Stage I - 'poor' (AQI 201-300); Stage II - 'very poor' (AQI 301-400); Stage III - 'severe' (AQI 401-450); and Stage IV - 'severe plus' (AQI above 450).

The Commission for Air Quality Management (CAQM), a statutory body responsible for developing strategies to combat pollution in the region, said the pollution levels are only "expected to increase further" owing to highly unfavourable meteorological and climatic conditions.

The city's AQI plunged to 422 at 10 pm, the worst this season so far. The 24-hour average AQI was 364 on Wednesday, 359 on Tuesday, 347 on Monday, 325 on Sunday, 304 on Saturday, and 261 on Friday.

Not just Delhi, several cities in neighbouring Haryana, Rajasthan and Uttar Pradesh also reported hazardous air.

These included Hanumangarh (438) and Sri Ganganagar (359) in Rajasthan; Hisar (414), Fatehabad (423), Jind (413), Rohtak (388), Sonepat (374), Kurukshetra (343), Karnal (343), Kaithal (379), Bhiwani (355), Faridabad (368) and Gurugram (297) in Haryana; and Ghaziabad (286), Noida (313) and Greater Noida (402) in Uttar Pradesh.

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'.

Scientists have warned of further deterioration of air quality in Delhi-NCR over the next two weeks.

An official from the India Meteorological Department reported that visibility reduced to just 500 metres at the Safdarjung Observatory around 7 am, gradually improving to 800 metres as temperatures increased during the day.

Health professionals have expressed concerns that air pollution is increasing asthma and lung problems in children and the elderly.

"We are recording a surge in the number of irritative bronchitis infections. It is recommended that people suffering from respiratory issues such as chronic bronchitis and asthma take their medicines regularly and do not go out in the open unless absolutely necessary," said Jugal Kishore, the head of the medicine department at Safdarjung Hospital.

Considering the spike in indoor pollution in Delhi, he advised people to use air purifiers in their homes.

Air pollution in India resulted in 1.67 million deaths in 2019 -- the largest pollution-related death toll in any country in the world -- and accounted for USD 36.8 billion in economic losses, according to a new study by researchers from the Global Observatory on Pollution and Health at Boston College, the Indian Council of Medical Research, and the Public Health Foundation of India.

One of the major reasons behind the accumulation of pollutants in recent days is the lack of rainfall during this post-monsoon season so far.

According to government data, Delhi's air quality in October 2023 was the worst since 2020, with meteorologists attributing it to the absence of rainfall. The capital recorded an AQI of 210 in October, compared to 210 in October last year and 173 in October 2021, according to the Central Pollution Control Board (CPCB).

In contrast to October 2022 (129 mm) and October 2021 (123 mm), Delhi experienced only one rainy day (5.4 mm of precipitation) in October 2023.

Unfavourable meteorological conditions, combined with emissions from firecrackers, paddy straw burning, and local pollution sources, contribute to hazardous air quality levels in Delhi-NCR during winter.

According to an analysis conducted by the Delhi Pollution Control Committee (DPCC), the capital experiences peak pollution from November 1 to November 15 when the number of stubble burning incidents in Punjab and Haryana increase.

The CAQM reported that the number of stubble burning incidents in Punjab and Haryana since September 15 has reduced by around 56 per cent and 40 per cent, respectively, compared to the corresponding period last year.

However, the agrarian states have seen a significant jump in farm fires over the last three days.

The Punjab government aims to reduce farm fires by 50 per cent in this winter season and eliminate stubble burning in six districts.

According to Punjab's action plan to curb paddy straw burning, about 31 lakh hectares of land in the state are under paddy cultivation, expected to generate around 16 million tonnes of paddy straw (non-basmati).

Haryana estimates that about 14.82 lakh hectares of land in the state are under paddy cultivation, expected to generate over 7.3 million tonnes of paddy straw (non-basmati). The state is making efforts to nearly eliminate farm fires this year.

According to a numerical model-based system developed by the Indian Institute of Tropical Meteorology (IITM) in Pune, vehicular emissions (11 per cent to 16 per cent) and stubble burning (seven per cent to 16 per cent) currently stand as the two major contributors to Delhi's air quality.

Delhi Environment Minister Rai announced on Wednesday that the city government would ban construction work in areas where the AQI remains above the 400-mark for five consecutive days.

The Delhi government launched a 15-point action plan last month to mitigate air pollution during the winter season, with a strong emphasis on addressing dust pollution, vehicular emissions, and open burning of garbage.

In line with the practice of the last three years, the Delhi government last month also announced a comprehensive ban on the manufacture, storage, sale, and use of firecrackers within the city.

It has launched "Red Light on Gaadi Off" campaign to curb vehicular pollution and plans to hire 1,000 private CNG buses to strengthen public transport and reduce vehicular pollution.