Delhi records the best air quality on Diwali day in eight years

Delhi’s air quality improved sharply just before Diwali this year.

Air Quality in Delhi Diwali Day: Delhi recorded its best air quality in eight years on Diwali day on Sunday, although pollution levels may rise due to fireworks and low night temperatures. Delhi residents had clear skies and abundant sunshine and the city’s 24-hour average Air Quality Index (AQI) stood at 218 at 4pm, the best in at least three weeks. Delhi recorded an AQI of 312 on Diwali last year, 382 in 2021, 414 in 2020, 337 in 2019, 281 in 2018, 319 in 2017 and 431 in 2016, according to Central Pollution Control Board data.

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’, 401 and 450 ‘severe’ and above 450 ‘serious plus’.

Saturday’s 24-hour average AQI was 220, the lowest level for the day before Diwali in eight years.

Delhi’s air quality improved sharply just before Diwali this year. The improvement can be attributed to Friday’s intermittent rainfall and wind speeds favorable for the dispersion of pollutants.

To put this in perspective, Thursday’s 24-hour average AQI was recorded at 437.

The city experienced ‘very poor’ to ‘severe’ air quality for two weeks from October 28, while a choking haze hung over the national capital during the period.

The India Meteorological Department (IMD) had earlier forecast a marginal improvement in air quality just before Diwali, due to favorable meteorological conditions including light rain under the influence of a western disturbance.

A western disturbance brought rain to most parts of northwest India, including Punjab and Haryana, effectively reducing the contribution of stubble burning smoke to Delhi’s air pollution.

The IMD had also forecast that once the western disturbance passes, wind speed would increase to around 15 kilometers per hour on Saturday, which would help disperse pollutants before Diwali.

In keeping with the practice of the past three years, Delhi has announced a complete ban on the production, storage, sale and use of fireworks in the city.

However, sporadic incidents of fireworks burning were reported in various parts of the national capital on Saturday and Sunday evening.

Low temperatures and bursting of fireworks could lead to a rise in pollution levels in Delhi late on Sunday.

Last year, a decline in stubble burning incidents, delayed rains, favorable meteorological conditions and an early Diwali ensured that the national capital did not turn into a gas chamber after the festival of lights.

According to data from the Decision Support System, a numerical model-based framework capable of identifying the sources of particulate matter pollution in Delhi, stubble burning in neighboring states, especially Punjab and Haryana, was responsible for 23 percent of Delhi’s air pollution . city ​​on Wednesday. On Thursday it was 33 percent and on Friday it was 10 percent.

The data also showed that transportation – another major cause of pollution in the city – has contributed 12 to 14 percent of Delhi’s polluted air in recent days.

Vinay Kumar Sehgal, chief scientist at the New Delhi-based Indian Agricultural Research Institute, expected a reduction in farm fires in Punjab and Haryana around Diwali due to wet conditions after rains.

On Friday, Delhi Environment Minister Gopal Rai said the government had postponed the implementation of the odd-even car rationing scheme as there had been a notable improvement in the city’s air quality due to the rains.

He said the government would review the air quality situation after Diwali and the ‘odd-even’ scheme could be invoked in case of a sharp increase in pollution levels.

Rai had earlier said that the scheme would be implemented in the city after the Supreme Court assessed its effectiveness and issued an order.

On Tuesday, the apex court questioned the effectiveness of the Delhi government’s car rationing programme, aimed at curbing vehicular pollution, terming it “all optics”.

Anticipating a further deterioration in air quality after Diwali, Rai announced on Monday that the scheme, which allows cars to operate on alternate days based on the odd or even last digit of their license plate number, would come into effect between November 13 and 20 .

Doctors say breathing Delhi’s polluted air is equivalent to the harmful effects of smoking about ten cigarettes a day.

Long-term exposure to high levels of pollution can cause or worsen respiratory problems such as asthma, bronchitis and chronic obstructive pulmonary disease (COPD) and dramatically increase the risk of cardiovascular disease, they said.

Strict restrictions imposed under the latest phase of the Centre’s air pollution control plan for Delhi-NCR – the Graded Response Action Plan (GRAP) – have also been implemented in the national capital.

The restrictions under Phase IV of the GRAP, which include a ban on all types of construction work and entry of polluting trucks in Delhi, came into effect on Sunday after air quality in the city fell to ‘severe plus’ levels (AQI above 450). .

GRAP categorizes actions into four phases: Phase I — Poor (AQI 201-300); Stage II – Very Poor (AQI 301-400); Stage III – Severe (AQI 401-450) and Stage IV – Severe Plus (AQI greater than 450).

Unfavorable meteorological conditions, combined with vehicular emissions, rice straw burning, fireworks and other local pollution sources, contribute to hazardous air quality levels in the Delhi-NCR during winters.

According to an analysis by the Delhi Pollution Control Committee, the city experiences a spike in pollution from November 1 to 15, when stubble burning incidents increase in Punjab and Haryana.

Delhi’s air quality is among the worst in the world’s capitals. Air pollution shortens lives in Delhi by nearly a dozen years, according to a report by the University of Chicago’s Energy Policy Institute in August.