Dirties Cities in the World 2026
Pollution Index
- Most surveys of the dirtiest cities focus upon air pollution. Other factors, such as water quality and sanitation services, can also contribute to a city’s overall “dirtiness”, but are typically measured separately and not compiled into a single ranking.
- Air quality is measured in micrograms (one-millionth of a gram, symbol µg) per cubic meter, abbreviated µg/m³.
- The Numbeo Pollution Index is based primarily on user survey responses about perceived pollution in cities, including air and water pollution, garbage and cleanliness, noise and light pollution, green spaces, and overall environmental comfort. Each response is converted into a numerical score from -2 to +2 and then normalized onto a 0–100 scale for easier comparison.
- The Exp Pollution Index is the same underlying Numbeo pollution score, but transformed using an exponential scale instead of a linear one. This means it exaggerates differences at the extremes, making very polluted cities appear much higher and very clean cities much lower compared to the standard index. It is mainly used to better highlight gaps between cities where pollution levels differ strongly.
Around 55% of the world’s population lives in cities, up from just 47% in 2000. This number is expected to rise to 68% by the year 2050 and continue to trend in the upward direction for the foreseeable future. While there are many advantages to living in condensed urban areas, they have the potential to cause serious long-term harm to the environment without the proper sustainable infrastructure in place. Unfortunately, such infrastructure is something of a novelty, and while the technology continues to develop, many cities around the world are beginning to experience the adverse effects of pollution first hand.
As of the end of 2019, Ghaziabad, India was the most dangerously polluted city in the world based on the Air Quality Index (AQI). AQI is a metric that determines the toxicity of a city’s air. As a city’s AQI increases, it becomes increasingly inhospitable for human breathability. The AQI takes five factors into consideration: ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
Ghaziabad, India has an AQI of 110.2. It’s air is considered “unhealthy” or even “hazardous” for most of the year. Six of the world’s top ten most polluted cities, according to the AQI, are located in India, where poor air quality leads to the premature deaths of up to 2 million residents each year. Part of the issue stems from India’s density and the concentrated volume of vehicle emissions and biomass burnoff from cooking and agriculture. Additionally, zoning is relatively arbitrary in many Indian cities and expansive industrial complexes have the tendency to infringe upon residential districts.
The list of the ten cities with the most severe air pollution according to the AQI:
- Ghaziabad, India (110.2)
- Hotan, China (110.1)
- Gujranwala, Pakistan (105.3)
- Faisalabad, Pakistan (104.6)
- Delhi, India (98.6)
- Noida, India (97.7)
- Gurugram, India (93.1)
- Raiwind, Pakistan (92.2)
- Greater Noida, India (91.3)
- Bandhware, India (90.5)
While air pollution is most hazardous to the average person, one could argue that it doesn’t necessarily exemplify the world’s “dirtiest” city. In the defense of many of the top cities on the previous list, AQI isn’t based purely on human intervention. Topography, climate, and natural disasters (forest fires) all have a considerable effect on a region’s air quality.
If we choose, instead, to evaluate “dirtiness” by the sheer volume of solid waste a city produces, then New York City is the dirtiest city in the world and it’s not even remotely close. Annually, the New York City Metropolitan area produces some 33.2 million metric tons of waste. With close to 19 million residents, that’s about 1.75 metric tons of waste per capita, over 3,800 pounds. The majority of New York’s waste is generated by businesses and industries who have begun to ship their garbage upstate or even several states over as the landfills reach capacity. While private households are not the bulk of the issue, they are not entirely absolved from the blame. The United States has consistently ranked above the 90th percentile for the amount of municipal waste generated per capita. As of 2019, the average American citizen produced 4.4 lbs of waste each day.
The cities in second and third place, Mexico City and Tokyo respectively, produce barely a third as much solid waste as New York City despite having higher populations.
The top ten most wasteful cities in the world, measured in millions of metric tons:
- New York City, United States (33.20)
- Mexico City, Mexico (12.20)
- Tokyo, Japan (11.90)
- Los Angeles, United States (11.10)
- Mumbai, India (10.03)
- Istanbul, Turkey (9.30)
- Jakarta, Indonesia (8.64)
- Cairo, Egypt (7.09)
- Osaka, Japan (6.70)
- Sao Paulo, Brazil (6.15)
