As Delhi's Air Pollution Rises, Here's Why The AQI Isn't Fully Accurate

The spike in air pollution is accompanied by an increase in health issues and respiratory deaths.

Diwali 2022: Air pollution levels in Delhi touched 600 on the Air Quality Index a day before Diwali, going well beyond hazardous levels.

(Image: Deeksha Malhotra/The Quint)

A day before Diwali 2022, air pollution levels in Delhi touched 600 on the Air Quality Index, going well beyond hazardous levels. And if the past years' trend continues, this particulate matter concentration will only get worse in the months of November and December.

Why should you care? Because the air you breathe is quite literally killing you. A 2019 study in The Lancet found that air pollution killed 1.67 million Indians in one year, the highest number in the world.

Exposure to this air, even for a short time, could trigger heart attacks in people with cardiac problems, respiratory problems, wheezing, fatigue and other complications in even healthy people.

Eight out of 10 of the world's most polluted cities are also in India, with Gurugram topping the list.

To top this off, the Air Quality Index, used to measure levels of particulate matter in the air, has one big flaw. Which we'll get to in a bit.

So, what are real reasons the Delhi-NCR belt witnesses horrific pollution from October to January? How can you tell what the REAL air quality is? And where does the Air Quality Index fall short? Let's find out.

What Are The Primary Causes of Air Pollution In Delhi?

All year round, air pollution levels in the capital and nearby areas remain in the unhealthy range, between 101 to 150 on the AQI.

This particulate matter concentration qualifies as unhealthy for sensitive groups of people, i.e., people suffering from respiratory problems.

According to the Observer Research Foundation and the Center for Science and Environment, the causes of heightened air pollution in the capital and nearby areas are:

• Industrial emissions

• Vehicular emissions

• Construction work

• Stubble burning in nearby states

• Diwali fireworks

But, it only gets worse. According to a 2019 report from the Center for Science and Environment, PM2.5 concentrations jumped tenfold in the hours immediately after Diwali, because of people lighting crackers and fireworks.

And, while air pollution levels begin to peak during and after Diwali, fireworks are just one factor driving up this massive health crisis.

According to the System of Air Quality and Weather Forecasting And Research (SAFAR), 46 percent of air pollution in Delhi is a result of stubble burning in the winter months.

The rise in particulate matter concentration in the air is exacerbated in the winter months by the winds in Delhi, or the lack thereof, which keeps any smog in the region static and prevents its efficient dispersal.

All the factors we mentioned, coupled with the onset of winter, creates the perfect cocktail of toxic fumes in the Delhi-NCR region and nearby states like Haryana, Bihar, and UP.

Why Is The Air Quality Index Flawed? 

In the first episode of 2019 HBO series Chernobyl, there's a scene where shortly after reactor 4 of the Chernobyl Nuclear Power Plant explodes, an engineer on the plant tells deputy chief engineer Dyatlov that the radiation level is “3.6 roentgen, but that's as high as the meter."

Dyatlov replies, "Not great, not terrible."

Later, we find that the radiation being released from the exposed reactor core, is closer to 15,000 roentgen, or "equal to nearly twice the radiation released by the bomb in Hiroshima. Every single hour. Hour after hour."

This perfectly illustrates the challenges with the Air Quality Index that India uses as its frame of reference.

The SAFAR AQI monitoring stations across the capital are capped at 999. However, data from the Central Pollution Control Board doesn't have this cap, and can track PM concentrations well beyond 999.

Which was why, in 2019, parts of Delhi like Anand Vihar witnessed PM 2.5 concentrations of as high as 2400 on the CPCB monitor! AQI readings from across India, not just Delhi, touched PM 2.5 concentration levels of 1600-2000.

However, at the same time, AQI readings from the Ministry of Earth Science's SAFAR monitoring stations only read 999 across the capital.

For context, an AQI of 300 and above is qualified as 'Hazardous' according to the World Air Quality Project's AQI meter. This means that residents of the capital were breathing air that was more than SIX TIMES beyond the hazardous range, and more than 20 times worse than the safe breathing range.

All while SAFAR's AQI stations said that PM2.5 levels were at 999.

SAFAR Air Quality vs CPCB Air Quality Index

The simplest way to get the most accurate AQI reading is to refer to both the SAFAR Air Quality Index (Or the World Air Quality Project's AQI monitor) as well as the CPCB's Air Quality Index and compare the two.

SAFAR AQI stations monitor concentrations of particulate matter, nitrogen, carbon monoxide, and other pollutants in the air in real-time. So, technically, they offer an accurate reading of the air quality till it touches 999. Once the AQI touches 999, you'd be better off comparing this reading with the CPCB's AQI monitor.

While the AQI has stayed below 999 as of this report, it could very likely cross this threshold into the 1000s and even 2000s, given Delhi's track record.

So, what steps have been taken to address the toxic air crisis?

What Steps Have Been Taken?

Air pollution was responsible for over 54,000 deaths in Delhi in 2020, according to an analysis of southeast Asia by Greenpeace.

According to cardiologist Dr. Ashok Seth, "Air pollution causes not just bad lung problems, breathing problems, asthma, and bronchitis, but also heart attacks. In fact, nearly 50 percent of the heart problems we see are caused by air pollution."

So, with these facts in mind, steps have been taken to counter the increased air pollution?

To reduce the contribution of Diwali fireworks to air pollution, the Delhi government has passed an order banning the storage, usage and sale of all types of firecrackers in the national capital till 1 January 2023.

The Commission for Air Quality Management has also implemented pollution control measures under the Graded Response Action Plan (GRAP) in the capital.

The four-stage action plan involves several steps to counter air pollution including stopping construction activities, prohibiting the use of diesel generators, increasing parking fees to discourage the use of private transport, prohibiting the entry of trucks into Delhi except for essential services, and even school closures to limit children's exposure to air pollution.

You can read more about the Delhi government's response to the rise in air pollution here.