India ranks fifth in polluted air globally in 2024, says IQAir report

India ranks as the fifth country worldwide that had the most polluted air in 2024 after Chad, Congo, Bangladesh and Pakistan, according to Switzerland-based air quality monitoring company IQAir.

However, the country marginally improved its position from third in 2023.

India saw a 7 per cent decline in PM2.5 concentrations last year, averaging 50.6 micrograms per cubic metre air (µg/m³) compared to 54.4 µg/m³ in 2023. Yet, six of the world’s ten most polluted cities are in India. New Delhi maintained consistently high pollution levels, with an annual average of 91.6 µg/m³, nearly unchanged from 92.7 µg/m³ a year ago, the report said.

IQAir analysed data from 40,000 air quality monitoring stations in 138 countries. More air quality monitors are being set up to counter the issue, the report said. This year, the report authors were able to incorporate data from 8,954 new locations and around a thousand new monitors as a result of efforts to better monitor air pollution.

Only 12 countries, regions, and territories recorded PM2.5 concentrations below the WHO annual PM2.5 guideline of 5.0 µg/m³, most of which were in the Latin America and Caribbean or Oceania region. However, in 2024, 17 per cent of cities included in the report met the WHO annual PM2.5 guideline level, up from 9 per cent in 2023, according to the report.

Air pollution remains a significant health burden in India, reducing life expectancy by an estimated 5.2 years. The World Health Organization (WHO) estimates that air pollution kills around 7 million people each year.

Instances of severe pollution persisted in 2024, particularly in northern states. Air quality in January was especially poor in Delhi and Himachal Pradesh. Baddi in Himachal Pradesh saw a monthly PM2.5 average of 165 µg/m³.

Air quality deteriorated sharply in Manipur in October, while November saw extreme pollution levels in Delhi, Punjab, Chandigarh, Haryana, and Himachal Pradesh with stubble burning remaining a major contributor to PM2.5 levels, accounting for 60 per cent of pollution during peak periods. Overall, 35 per cent of Indian cities reported annual PM2.5 averages exceeding 10 times the World Health Organisation guideline.

The WHO air quality guideline states that annual average concentrations of PM2.5 should not exceed 5 µg/m3, while 24-hour average exposures should not exceed 15 µg/m3 more than 3-4 days per year.

PM2.5, fine particulate matter of 2.5 micrometres or less in diameter, is the most dangerous pollutant because it can penetrate the lung barrier and enter the blood system, causing cardiovascular and respiratory disease and cancers. It affects more people than other pollutants and has health impacts even at very low concentrations.

India faces significant air quality challenges, with major pollution sources including vehicular emissions, industrial discharges, construction dust, and the burning of crop residues. In urban centres like Delhi, vehicular emissions are a leading contributor to fine particulate matter (PM2.5), exacerbated by traffic congestion and fuel adulteration. Seasonal agricultural practices, particularly the burning of crop residues in states like Punjab and Haryana, further deteriorate air quality during winter months. Industrial emissions and construction activities also contribute significantly to pollution levels. Despite governmental measures, such as the National Clean Air Programme aiming to reduce pollution levels, challenges persist due to inconsistent policy implementation and inadequate infrastructure.

“Vehicular emission is a major source of pollution in Delhi-NCR. Emission per unit distance travelled increases for older vehicles. Public transport needs to be revamped,” suggested Sagnik Dey, professor at the Centre for Atmospheric Sciences, IIT Delhi.

“The government is already pushing for EVs (electric vehicles) with better infrastructure. Scientific evidence already suggested that we require an airshed approach and CAQM is there to efficiently implement airshed management within NCR across the five states. Accountability and interim targets to track progress will be key to strengthen the clean air implementation, along with synergising with climate actions,” Dey added.

To combat air pollution in Delhi, the state government, last week, announced that vehicles older than 15 years will be denied fuel at petrol pumps starting April 1.

Last October, India’s Supreme Court affirmed that breathing clean, pollution-free air is a fundamental right. The top Court found that the federal government and the governments of Delhi, Punjab, Haryana, Uttar Pradesh, and Rajasthan must more effectively control air pollution at its source. Despite numerous rulings requiring government action, the court determined that the governments had taken only limited action to curb stubble burning and must submit reports demonstrating compliance with court orders. During a November hearing, the Supreme Court criticised Delhi officials for “serious lapses” in curbing pollution under the Graded Response Action Plan (GRAP), multi-stage emergency measures for reducing pollution during poor air quality days.

On December 16, 2024, Stage 4 of GRAP, the strictest level of anti-pollution measures, was enforced as the air quality index (AQI) exceeded 400, indicating “severe” conditions. This marked the second instance in the last winter, with the first triggered on November 18 due to stubble burning, which pushed AQI to 494.

A study by the Centre for Science and Environment conducted last year found that during mid-October to early November — when farmers burn paddy stalks — only 8 per cent of Delhi-NCR’s air pollution came from stubble burning, while nearly two-thirds originated from local sources, with the transport sector contributing more than half.

According to the International Energy Agency, road transport accounts for 12 per cent of India’s energy-related CO2 emissions and is a major contributor to urban pollution. As demand for private transportation and goods movement grows, energy use and CO2 emissions from road transport could double by 2050.