Brian Barton
Air pollution is a pressing issue that affects the health and well-being of people worldwide. According to the World Health Organization (WHO), air pollution from the burning of coal, oil, and gas claims the lives of approximately 9 million people annually. This is due to the increased mortality risk from stroke, heart disease, lung cancer, and acute respiratory infections. While pollution is prevalent in middle- to low-income countries due to poor standards, it is also a significant issue in major cities. India, in particular, stands out, with 12 of the world's 15 most polluted cities and 63 of the top 100 polluted places. However, China is also a notable contributor, with Beijing previously known for its poor air quality, although it has shown improvement in recent years.
| Characteristics | Values |
|---|---|
| Date of Information | March 2025 |
| Number of Cities in the World's Top 20 Most Polluted Cities List that are in Asia | 19 |
| Country with the Most Cities in the Top 20 | India (13) |
| Country with the Second-Most Cities in the Top 20 | Pakistan (4) |
| Other Countries with Cities in the Top 20 | China, Kazakhstan, Chad |
| Most Polluted City in the World | New Delhi, India |
| World's Most Polluted Capital | New Delhi, India (6th year in a row) |
| New Delhi's Annual PM2.5 Level | 108.3 µg/m³ |
| New Delhi's AQI Concentration | 169 |
| Other Cities in India in the Top 10 | Greater Noida, Noida, Ghaziabad, Faridabad, Gurgaon, Bhiwadi, Patna, Sonipat, Muzaffarnagar |
| Country with the Most Polluted Air | Chad |
| Cities with the Worst Pollution in North America | All in California |
| Number of Cities in the Top 25 Most Polluted Cities List that are in India | 13 |
| Number of Cities in the Top 25 Most Polluted Cities List that are in China | 3 |
| Number of Cities in the Top 25 Most Polluted Cities List that are in Pakistan | 3 |
| Other Countries with Cities in the Top 25 | Bangladesh, Iraq, Israel, South Africa, Nepal, Uganda |
| City with the Highest PM2.5 Level in 2024 | Lahore, Pakistan (150.4 µg/m³) |
Explore related products
What You'll Learn
New Delhi, India, is the world's most polluted city
New Delhi's toxic air is primarily caused by the burning of fossil fuels, vehicular emissions, and poor waste management practices. The city is engulfed in smog, with visibility on the streets dropping to as low as 50 meters (164 feet). The air pollution crisis has severe health consequences for the city's over 30 million residents, including respiratory conditions, cardiovascular diseases, lung cancer, and reduced life expectancy. The social inequalities in the city are amplified as the poor suffer the most from the toxic air.
The pollution in New Delhi has worsened over the last decade, with the winter months being particularly challenging due to intense and prolonged spells of smog. The high levels of PM 2.5 pollutants, combined with extreme heat events and intensified pollen seasons, create a deadly cocktail that exacerbates allergic airway diseases like allergic rhinitis and asthma. The National Capital Region (NCR) of India, which includes New Delhi, witnessed a concerning surge in PM2.5 levels in 2023, peaking at a monthly average of 255 μg/m3 in November.
The Indian government has recognized the severity of the issue, with the region's chief minister declaring it a "medical emergency." However, despite slight improvements in 2024, the NCR region remains heavily polluted, and the health risks affect an estimated 1.36 billion people living in the country. The situation in New Delhi highlights the urgent need for sustainable practices, cleaner technologies, and a transition away from fossil fuels to combat air pollution and mitigate its devastating impacts on public health and the environment.
New Delhi's status as the world's most polluted city underscores the pressing need for global action to address air pollution. With air quality recognized as a universal human right, decisive steps must be taken to implement cleaner energy solutions and improve the health and well-being of those affected by toxic air. The city's struggle with pollution serves as a stark reminder of the critical importance of prioritizing sustainable practices to ensure a healthier future for all.
The Pollution Problem in New York City
You may want to see also
Explore related products
13 of the top 20 polluted cities are in India
India is home to 13 of the world's 20 most polluted cities, according to the World Air Quality Report by IQAir. Delhi, the capital of India, has been named the most polluted city in the world, with an alarming AQI concentration of 169. It is the world's most polluted capital for the sixth year in a row, recording an annual PM2.5 level of 108.3 µg/m³. Other cities in India that feature among the world's most polluted include Byrnihat, Punjab's Mullanpur, Faridabad, Loni, Gurugram, Ganganagar, Greater Noida, Bhiwadi, Muzaffarnagar, Hanumangarh, Noida, Kolkata, Mumbai, Hyderabad, Bengaluru, and Chennai.
The high level of pollution in Byrnihat, a town on the Assam-Meghalaya border, is due to emissions from local factories, including distilleries. In 2024, Byrnihat recorded a staggering annual average PM2.5 concentration of 128.2 μg/m³. Delhi's poor air quality can be attributed to various factors, including vehicular emissions, industrial activities, and poor waste management. The city's pollution levels have worsened, with the annual average PM2.5 concentration rising from 102.4 micrograms per cubic metre in 2023 to 108.3 micrograms per cubic metre in 2024.
While India has made some progress in reducing air pollution, with a 7% decline in PM2.5 concentrations in 2024, the country still faces significant challenges. Nearly 35% of Indian cities recorded annual PM2.5 levels exceeding the World Health Organisation's guidelines by more than ten times. The former director-general of the Indian Council of Medical Research has emphasized the need for strict enforcement of emission laws and incentives for cleaner technologies to combat the country's air pollution crisis.
The health impacts of air pollution in these Indian cities include respiratory conditions, cardiovascular diseases, and lung cancer. High air pollution levels are especially dangerous for children and the elderly. It also has economic consequences, leading to increased medical costs and reduced productivity. India's pollution problem extends beyond its borders, as it is ranked as the fifth most polluted country globally, with six of the world's ten most polluted cities.
Understanding Suspended Particulate Matter: Sources and Impacts
You may want to see also
Explore related products
The top 5 most polluted countries are in Asia
Asia is home to some of the world's most polluted countries, with air quality posing a serious health risk to residents. The top five most polluted countries in Asia, as of 2024, are:
- Bangladesh: Bangladesh has consistently ranked as one of the most polluted countries globally. In 2023, it had the highest average PM2.5 concentration in Asia at 161 μg/m³.
- India: India is another country with severe air pollution levels. In 2023, it recorded an average PM2.5 concentration of 84 μg/m³. Notably, Begusarai, a city in northern India, was ranked as the world's most polluted city in 2024, with PM2.5 levels 23 times higher than WHO guidelines.
- Pakistan: Pakistan struggles with poor air quality, especially in cities like Lahore, which is notorious for its high levels of industrial emissions, vehicular exhaust, and agricultural burning practices. In 2023, Pakistan recorded an average PM2.5 concentration of 147 μg/m³.
- Bahrain: Bahrain is one of the top five most polluted countries in Asia, according to a list that ranked countries based on pollution levels in 2025.
- Nepal: Nepal is the fifth most polluted country in Asia. Kathmandu, its capital city, often experiences poor air quality due to various factors, including vehicle emissions, dust, and the burning of agricultural waste.
These countries face significant challenges in improving their air quality due to factors such as rapid urbanization, industrial growth, and poor waste management practices. The health impacts of air pollution in these countries are severe, reducing life expectancy and causing respiratory issues, cardiovascular diseases, and lung cancer.
China's Pollution Battle: Strategies and Successes
You may want to see also
Explore related products
California is home to North America's most polluted cities
California is home to some of North America's most polluted cities, with Los Angeles, Bakersfield, and Fresno being ranked among the top 25 most polluted cities in the United States. In 2025, nearly half of the people in the United States lived in areas where the air quality was considered unhealthy, earning a failing grade in the "State of the Air" report. More than 42 million people resided in counties that received failing grades for all three measures of air pollution: ozone, year-round particle pollution, and short-term particle pollution.
Particle pollution, which is prevalent in many California cities, poses a significant health risk to residents. These tiny particles can be inhaled, bypassing the body's natural defenses, and leading to an increased risk of lung cancer. Additionally, particle pollution has been linked to premature death, heart attacks, strokes, and emergency room visits. Ozone pollution, often found in areas with heavy traffic, can irritate the lungs, causing inflammation similar to a sunburn.
California's air pollution has multiple sources, including vehicular emissions, industrial activities, and agricultural practices. The state's geographic features, such as mountain ranges and valleys, can also trap pollutants and contribute to poor air quality in certain regions. Additionally, wildfires, which have become more frequent and severe due to climate change, release large amounts of smoke and particulate matter into the atmosphere, further degrading air quality.
The impact of air pollution extends beyond physical health. It can trigger asthma attacks, harm lung development in children, and disproportionately affect vulnerable populations, including people of color, those with lower incomes, and individuals with pre-existing lung diseases. The economic consequences of air pollution are also significant, leading to increased medical costs and reduced productivity.
While California has implemented measures to improve air quality, such as stricter emissions standards and the promotion of clean energy technologies, the state continues to face challenges in reducing pollution levels. The complex interplay of geographic, economic, and social factors contributes to California's struggle with air pollution, making it a persistent issue for many of its cities.
Sources of Nutrient Pollution: Agricultural Runoff and its Impact
You may want to see also
Explore related products
Chad is the most polluted country in Africa
Chad, a landlocked country in north-central Africa, is currently the most polluted country on the continent. According to IQAir's 5th Annual World Air Quality Report in 2023, Chad recorded an annual average PM2.5 concentration of 89.7 µg/m³, exceeding the World Health Organization's recommended limit of 10 µg/m³ by more than 17 times. This concentration of fine particulate matter is known to be harmful to human health, and Chad's levels are even higher than countries like Iraq, Pakistan, and Bangladesh, which are also notorious for poor air quality.
Chad's air pollution is attributed to various factors, including the oil, textile, and meatpacking industries, vehicle emissions, and waste burning. The country's electricity generation also relies entirely on fossil fuels, and pollution from mining and petroleum extraction further exacerbates the issue. Additionally, indoor air pollution, largely caused by the use of wood and charcoal for energy, results in an estimated 9,600 premature deaths every year.
The lack of comprehensive data and effective policies exacerbates Chad's air pollution crisis. As of 2023, only a single monitor in the city of N'Djamena provided real-time, publicly available air quality data for the entire country. This data gap highlights the need for more robust monitoring networks to accurately assess the situation. Moreover, Chad has been criticized for its lack of emission regulations, incentives for clean production, and installation of pollution prevention technologies.
To address these challenges, Chad is promoting non-grid/grid electrification, cleaner cooking fuels, and clean cookstoves. However, the country still has a long way to go in terms of enforcing emission regulations, promoting alternative energy sources, and implementing effective waste management strategies. By taking these steps, Chad can begin to improve its air quality, protect the health of its citizens, and mitigate its environmental impact.
Drinking Straws: A Pollution Estimate
You may want to see also
Frequently asked questions
New Delhi, India, ranks as the most polluted city in the world in 2025, with an average AQI of 169.
The top 5 most polluted countries in the world are Bangladesh, Pakistan, India, Bahrain, and Nepal.
The major sources of air pollution include fossil fuel use, vehicular emissions, industrial activities, agriculture, and poor waste management.
