Delhi, India, currently holds the distinction of being the major city with the worst air pollution on Earth.
In a recent live ranking of major cities, Delhi recorded an Air Quality Index (AQI) of 601, indicating extremely hazardous air quality. This level poses a significant health risk to all individuals exposed.
Top Most Polluted Major Cities
Based on current live rankings, the cities experiencing the most severe air pollution, measured by their AQI⁺ US values, include:
| Rank | Major City, Country/Region | AQI⁺ US |
|---|---|---|
| 1 | Delhi, India | 601 |
| 2 | Dhaka, Bangladesh | 304 |
| 3 | Lahore, Pakistan | 229 |
| 4 | Accra, Ghana | 215 |
Understanding Air Quality Index (AQI)
The Air Quality Index (AQI) is a standardized scale used to communicate the level of air pollution and its associated health risks. A higher AQI value signifies a greater level of air pollution and a higher risk to public health.
- 0-50 (Good): Air quality is satisfactory, posing little or no risk.
- 51-100 (Moderate): Air quality is acceptable; however, some individuals sensitive to air pollution may experience minor health concerns.
- 101-150 (Unhealthy for Sensitive Groups): Members of sensitive groups may experience health effects, while the general public is typically unaffected.
- 151-200 (Unhealthy): Everyone may begin to experience health effects; sensitive groups may experience more serious effects.
- 201-300 (Very Unhealthy): Health warnings of emergency conditions; the entire population is likely to be affected.
- 301+ (Hazardous): Health alerts of emergency conditions. The entire population is more likely to be affected, with serious health effects. Delhi's AQI of 601 falls well into this hazardous category, signifying critical and life-threatening levels of pollution.
Health Impacts of Severe Air Pollution
Chronic exposure to high levels of air pollution can lead to a wide range of severe health problems across all age groups:
- Respiratory Issues: Increased incidence and exacerbation of conditions such as asthma, bronchitis, and chronic obstructive pulmonary disease (COPD).
- Cardiovascular Diseases: Elevated risks of heart attacks, strokes, and irregular heart rhythms due to the strain on the cardiovascular system.
- Neurological Effects: Emerging research suggests links to cognitive decline, neurodevelopmental issues in children, and an increased risk of neurological disorders.
- Cancers: A significant contributor to lung cancer and potentially other forms of cancer.
- Premature Mortality: Air pollution is recognized as a leading environmental risk factor contributing to millions of premature deaths globally each year.
Children, the elderly, and individuals with pre-existing respiratory or cardiovascular conditions are particularly vulnerable to the adverse effects of poor air quality.
Factors Contributing to Urban Air Pollution
Major urban centers like Delhi face complex challenges that contribute to their severe air pollution levels:
- Vehicular Emissions: A dense population of vehicles, often including older models with less stringent emission controls, releases a high volume of pollutants.
- Industrial Emissions: Unregulated or poorly regulated industrial activities contribute significant amounts of particulate matter, sulfur dioxide, and nitrogen oxides into the atmosphere.
- Construction Dust: Rapid urbanization and extensive construction projects generate substantial amounts of airborne particulate matter.
- Agricultural Burning: Seasonal burning of crop stubble in surrounding agricultural regions can lead to large plumes of smoke drifting into cities.
- Geographical and Meteorological Conditions: Cities located in landlocked basins or experiencing frequent temperature inversions can trap pollutants close to the ground, preventing their dispersion.
- Waste Burning: Open burning of municipal and industrial waste releases toxic gases and particulate matter.
Addressing Urban Air Pollution
Mitigating urban air pollution requires a comprehensive and sustained approach that integrates policy, technological advancements, and public participation:
- Transition to Cleaner Energy: Promoting the adoption of renewable energy sources and cleaner fuels for both industrial operations and urban transportation.
- Strict Emission Standards: Implementing and rigorously enforcing stringent emission norms for vehicles, factories, and power plants.
- Sustainable Transportation: Investing in and expanding efficient public transportation networks, promoting active mobility (walking and cycling), and encouraging electric vehicles to reduce reliance on private, fossil-fuel-powered transport.
- Improved Waste Management: Establishing efficient waste collection, segregation, and processing systems to eliminate open burning practices.
- Green Infrastructure Development: Expanding urban green spaces, planting more trees, and creating green corridors to help absorb pollutants and improve local air quality.
- Public Awareness and Education: Educating citizens about the sources and impacts of air pollution, and encouraging individual actions that contribute to cleaner air.
- Cross-Border and Regional Cooperation: Addressing transboundary air pollution issues, such as agricultural stubble burning, through coordinated efforts between administrative regions.
Delhi's critical air pollution levels underscore the urgent global need for comprehensive and sustained efforts to improve air quality for the health and well-being of its residents and similar urban populations worldwide.
