New Delhi: India's capital, New Delhi, has overtaken Pakistan's Lahore to become the world's most polluted major city in a live air quality ranking, as worsening smog raises concerns about public health and the continuing pollution crisis in South Asia. According to IQAir's global air quality ranking, Delhi recorded an Air Quality Index (AQI) of 334 on Friday, compared with 308 in Lahore. India's Central Pollution Control Board (CPCB) separately reported an AQI of 403 in Delhi, placing the city's air quality in the severe category under India's national measurement system.
The different readings reflect the separate measurement methods used by IQAir and Indian authorities. However, both indicate seriously polluted air in the capital. The figures represent observations at particular times and may change as weather conditions and pollution levels shift. Thick smog has reduced visibility across parts of Delhi, affecting roads and surrounding areas. The deteriorating conditions have added to concerns among residents, particularly those who must travel or work outdoors.
The latest deterioration comes despite emergency measures introduced by authorities. On November 6, the Commission for Air Quality Management (CAQM) activated Stage III of the Graded Response Action Plan (GRAP) across the National Capital Region, which includes Delhi and neighbouring areas. The restrictions include limits on construction and demolition activities that generate dust, along with measures to control road dust and encourage the use of public transport. Authorities have also introduced additional measures to reduce people's exposure to polluted air.
Schools have been directed to adopt hybrid learning arrangements for pupils up to Class V, allowing lessons to take place both online and in classrooms. Authorities have also encouraged government and private organisations to consider working from home to reduce traffic and pollution. Delhi's position in the global ranking has changed several times during November, with the Indian capital and Lahore exchanging places as pollution levels fluctuated. Lahore had previously occupied the top position, reflecting the wider air quality crisis affecting major cities in northern India and Pakistan.
Several factors contribute to Delhi's pollution, including vehicle emissions, construction dust, industrial activity and agricultural stubble burning in neighbouring regions. During winter, colder temperatures and weak winds can prevent pollutants from dispersing, allowing harmful particles to accumulate close to the ground. Firecrackers used during Diwali celebrations have added to the pollution problem. Despite restrictions imposed by authorities, fireworks continued in several areas during the festival. Earlier reports indicated a significant increase in fine particulate pollution following the celebrations. However, the precise contribution of fireworks to Delhi's pollution levels on November 13 has not been established.
The pollution crisis has also contributed to tensions between India and Pakistan. Marriyum Aurangzeb, Pakistan's Punjab Environment Protection Minister, previously blamed pollution carried across the border from India following Diwali celebrations for worsening air quality in Lahore. However, the exact contribution of cross border pollution has not been independently established. Health experts warn that prolonged exposure to polluted air can cause serious respiratory and cardiovascular problems. Fine particulate matter, particularly PM2.5, can penetrate deep into the lungs and enter the bloodstream, increasing the risk of heart disease, stroke and other health conditions.
Children, older people and individuals with existing respiratory or heart conditions are particularly vulnerable. The World Health Organization has warned that air pollution poses a major threat to public health and recommends much lower levels of fine particulate matter than those recorded during severe pollution episodes. The continuing deterioration highlights the difficulty of controlling pollution through temporary restrictions alone. Delhi and other cities in the region face the challenge of addressing emissions from multiple sources, particularly during the winter months when weather conditions can make air quality worse.
With severe pollution continuing to affect the capital, sustained action to reduce emissions and protect residents remains a major challenge for authorities.