Air quality in the world
Air quality index (AQI⁺) and PM2.5 air pollution in the world • 16:21, Aug 02
Live AQI⁺ City Ranking
World major city air quality ranking
# | Cities | AQI⁺ US | |
---|---|---|---|
1 | ![]() Kinshasa | 178 | |
2 | ![]() Kolkata | 120 | |
3 | ![]() Doha | 119 | |
4 | ![]() Baghdad | 108 | |
5 | ![]() Lahore | 107 | |
6 | ![]() Minneapolis | 106 | |
7 | ![]() Baku | 105 | |
8 | ![]() Dubai | 105 | |
9 | ![]() Dhaka | 98 | |
10 | ![]() Incheon | 97 |
World most polluted city
What city has the worst air quality?


Worst air quality country ranking
Better understand air pollution
Health effects and sources of air pollution
What are the main risk factors of death worldwide?
Of 62 million people who die per year (as of 2021), by risk factor:
# | Risk factors | Deaths |
---|---|---|
1 | High blood pressure | 10.9M |
2 | Air pollution (Outdoor & Indoor) | 8.1M |
3 | Smoking | 6.2M |
4 | High blood sugar | 5.3M |
5 | Outdoor particulate matter pollution | 4.7M |
6 | Obesity | 3.7M |
7 | High cholesterol | 3.6M |
8 | Indoor air pollution | 3.1M |
9 | Diet high in sodium | 1.9M |
10 | Alcohol use | 1.8M |
11 | Diet low in fruits | 1.7M |
12 | Diet low in whole grains | 1.5M |
13 | Low birthweight | 1.5M |
14 | Secondhand smoke | 1.3M |
Connected to air pollution related risks
Source: IHME, Global Burden of Disease (2024) – with minor processing by Our World in Data
Primary Sources of PM2.5 Pollution
As PM2.5, fine dust particles up to 2.5 micrometers in diameter, can penetrate deep into the lungs and enter the bloodstream, they pose significant health risks. Sources vary greatly by location, but these are the most common sources globally.
Coal combustion
Gasoline combustion
Diesel combustion
Wood combustion
Motor combustion
Industrial processes
Fires
Gas-to-particle conversion
How does air pollution affect children?
Respiratory issues
Increased asthma and bronchitis cases
Reduced lung function
Long-term exposure can impair lung development
Cognitive development
Potential impacts on brain development and academic performance
99%
Of the world's population lives in places where air quality exceeds the annual WHO guideline limits.
Source: World Health Organization
8.1 Million
Of deaths worldwide can be attributed to air pollution.
4.7 million
Due to outdoor particulate matter air pollution3.1 million
Due to indoor air pollution0.5 million
Due to outdoor ozone pollutionSource: Health Effects Institute 2021 - Numbers for 2021
100/100,000
People worldwide die from air pollution
58/100,000
From outdoor particulate matter39/100,000
From indoor air pollution6/100,000
From outdoor ozone pollutionSource: IHME (Institute for Health Metrics and Evaluation) 2024
Learn more about air pollution in the World
What causes bad air quality?
Air pollution can be created by both manmade and natural sources. Natural sources include windblown or kicked-up dust, dirt and sand, volcanic smoke, and burning materials. Manmade sources, meaning that pollution is created by the actions of human beings, tend to be the leading contributor to air pollution in cities and are inherently more able to be influenced by regulations. Manmade sources primarily include various forms of combustion, such as from gas-powered transportation (planes, trains, and automobiles) and industrial businesses (power plants, refineries, and factories), biomass burning (the burning of plant matter or coal for heating, cooking, and energy), and agriculture.
The contribution of various air pollution sources to a location’s air quality is highly dependent on the city’s location and regulations. Each location has its own mix of contributors and pollutants. Sources are commonly categorized into the following:
Industry
Industry includes pollution from facilities such as manufacturing factories, mines, and oil refineries as well as coal power plants and boilers for heat and power generation.
Industrial activity is a major global source of nitrogen oxides (NOx), hydrogen sulfide, volatile organic compounds (VOCs), and particulate matter, all of which contribute to ozone and smog.
Agriculture
The heavy use of fertilizers on agricultural land is a significant contributor to fine-particulate air pollution. A study in Geophysical Research Letters found that pollution generated from farms outweighed all other manmade sources of PM in much of the United States, Europe, Russia, and China.
Globally, agricultural land use is on the rise due to an increased demand for animal products and per capita food.
Transport
Air pollution from transport refers primarily to fuel combustion in motor vehicles, such as in cars, trucks, trains, planes, and ships. Transport emissions are a major contributor to elevated levels of fine particulate matter (PM2.5), ozone, and nitrogen dioxide (NO2).
The majority of emissions from transportation occur in the world’s top vehicle markets, as there tends to be a strong correlation between per capita transport emissions and incomes. As standards of living and economic activity increases, so too does the demand for transportation.
Natural sources
Natural air pollution sources include naturally occurring phenomena such as volcanic activity, wildfires, and dust or sandstorms. The impact of natural sources on air quality is highly dependent on the local environment. For example, locations near large deserts like the Sahara are greatly impacted by windblown dust and sand, while forested locations are more likely to experience air pollution from wildfires.
Household
Household air pollution refers to personal activities, such as residential cooking and heating with coal or wood burning as well as the building and construction of homes and furnishings.
Wildfires and open burning
The burning of plant matter emits large amounts of pollutants, as does burning other solid fuels like coal. Burning organic material emits particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), sulfur dioxide (SO2), lead, mercury, and other hazardous air pollutants (HAPs). These fires may occur organically, accidentally, or intentionally. Due to the frequently massive size of these fires, both wildfires and open burning have the potential to cause far-reaching air pollution.
Can air pollution cause health problems?
Air pollution refers to substances in the air that are detrimental to either human health and/or the planet as a whole. At significant levels, all types of air pollution pose a risk for adverse health effects. The amount of risk for health complications depends on one’s overall health, the pollutant type, the concentration, and the length of exposure to polluted air.
Impact of breathing unhealthy air - overview:
The World Health Organization (WHO) has deemed air pollution as the greatest environmental health risk in 2019, estimated to contribute to 7 million premature deaths annually. Among children under the age of 15, it is the leading cause of death, killing 600,000 every year.
Air pollution is described as a ‘silent killer’ because it is rarely the direct cause of death. Rather, air pollution is the world’s 4th leading contributing cause of early death, accounting for:
- 29% of all deaths and disease from lung cancer
- 17% of all deaths and disease from acute lower respiratory infection
- 24% of all deaths from stroke
- 25% of all deaths and disease from coronary heart disease
- 43% of all deaths and disease from chronic obstructive pulmonary disease
It is estimated that 99% of the global population breathes unhealthy air. While this figure varies region to region, nowhere is without risk. The 2024 World Air Quality Report found that 91% out of 138 countries and regions around the globe exceeded the WHO annual PM2.5 guideline value of 5 µg/m3, with the region of Central & South Asia among to the top ten most polluted cities in the world.
High air pollution levels can cause health problems including:
- Short-term effects: difficulty breathing, chest pain, wheezing, coughing, general respiratory discomfort, and irritation of the eye, nose, and throat.
- Long-term effects: lung tissue damage, cancer, early death, and the development of respiratory illnesses such as asthma, bronchitis, and emphysema.
Groups most susceptible to severe adverse health effects from air pollution include those with:
- Heart disease, such as coronary artery disease (CAD) or congestive heart failure
- Lung disease, such as asthma, emphysema, or chronic obstructive pulmonary disease (COPD)
- Older adults and the elderly
- Children under the age of 14
- Pregnant women
- Outdoor workers
- Athletes who exercise outdoors vigorously
Health effects from specific air pollutants
Ground-level Ozone | Particulate Matter (PM) and Wildfire Smoke | |
---|---|---|
Short-term | Long-term | |
|
|
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How can I protect myself from air pollution?
How can I improve air quality in my home?
Indoor air quality is not safe from outdoor air pollution. Moreover, there are numerous emission sources specific to indoor environments that can lead to heightened indoor air pollution levels. In order to improve air quality at home, both indoor ventilation and indoor sources should be managed.
Indoor air pollution mitigation methods include:
- Check current and forecast air quality levels in your area. Follow the health recommendations for current conditions.
- Keep windows and doors closed. Seal door and window gaps to minimize leakage.
- When outdoor air is heavily polluted, set air conditioning (HVAC) systems with fresh air intake to their recirculate mode.
- Use air purifiers or high-efficiency HVAC filters (such as HEPA or HyperHEPA filters) to remove fine particles from the air.
In the event indoor air pollution levels are already exceedingly high:
- Avoid strenuous activity, such as working out, to reduce the amount of polluted air you inhale.
- Wear an N95 pollution mask, if available.
- Run air purifiers frequently on their highest output setting.
- Evacuate if indoor air quality levels become “hazardous” which can happen in the event of nearby wildfires.
How can masks protect from air pollution?
Masks are very effective in reducing exposure to air pollution. While the broad category of air pollution masks includes gas masks for dealing with highly toxic chemicals, the majority of ambient air pollution masks on the market only filter particle pollution. For daily use, these masks are generally sufficient because outdoor environments rarely experience gases at the same dangerous levels as particles. Ambient air pollution masks can help protect an individual from PM2.5, viruses, bacteria, and allergens.
In evaluating the effectiveness of pollution masks, three components should be evaluated: pollution filter, mask seal, and ventilation.
- Pollution filter: Pollution filters are typically given a rating of either N90, N95, N99, or N100. The rating states the percentage of particulate matter (> 0.3 µg) the mask is capable of blocking. An N95 mask, for example, blocks against 95% of particulate matter larger than 0.3 micrograms. This includes the vast majority of PM2.5 and PM10. The higher the rating, the more effective the mask filter, assuming the mask seal and ventilation components work properly.
- Mask seal: Regardless of a mask’s pollution filter rating, masks that do not seal around one’s face are not effective because air will primarily flow in unfiltered through the sides of the mask. A good mask seal should cause the mask to suction to one's face during inhalation. For flexible, disposable masks, this suction should be visible, causing the filter to bend inwards creating a concave surface. For masks with a more solid construction, it should be possible to feel a slight increase in pressure when breathing in. If a mask is not sealed well to one’s face, air will primarily flow in through the open sides of the mask.
- Ventilation (CO2 valve): Ventilation makes masks more breathable while also reducing moisture and CO2 accumulation. While not a feature of all masks, many use a coin-sized CO2 valve to provide directed outflow. Breathing in poorly ventilated air high in CO2 can contribute to short-term effects such as headaches, lethargy, dizziness, and nausea. Masks with a ventilation valve are not effective for reducing the spread of viruses, as breathing output is not filtered.
Disposable surgical masks are affordable and accessible. They are also surprisingly effective against particle pollution. An Edinburgh study conducted by the Particle and Fiber Toxicology tested surgical masks down to .007 µg and found that the material of surgical masks were capable of blocking 80% of particles.
In another study, a fit test was applied to surgical masks in order to more accurately test their effectiveness, noting the generally loose fit. In this test, the rate of filtration fell to 63% as a result of the leakage around the mask.
While both tests reveal that surgical masks are significantly less efficient than respirator masks (rated N90-N100), they do help reduce exposure to fine particulate pollution at a very low cost.
What is the most polluted country/region in the world?
- Afghanistan
- Aland Islands
- Albania
- Algeria
- American Samoa
- Andorra
- Angola
- Anguilla
- Antarctica
- Antigua and Barbuda
- Argentina
- Armenia
- Australia
- Austria
- Azerbaijan
- Bahamas
- Bahrain
- Bangladesh
- Barbados
- Belarus
- Belgium
- Belize
- Benin
- Bermuda
- Bhutan
- Bolivia
- Bonaire, Saint Eustatius and Saba
- Bosnia Herzegovina
- Botswana
- Brazil
- Brunei
- Bulgaria
- Burkina Faso
- Burundi
- Cambodia
- Cameroon
- Canada
- Cape Verde
- Cayman Islands
- Central African Republic
- Chad
- Chile
- China
- Colombia
- Comoros
- Costa Rica
- Croatia
- Cuba
- Curacao
- Cyprus
- Czech Republic
- Democratic Republic of the Congo
- Denmark
- Djibouti
- Dominica
- Dominican Republic
- Ecuador
- Egypt
- El Salvador
- Equatorial Guinea
- Eritrea
- Estonia
- Ethiopia
- Faroe Islands
- Fiji
- Finland
- France
- French Polynesia
- Gabon
- Gambia
- Georgia
- Germany
- Ghana
- Greece
- Greenland
- Grenada
- Guam
- Guatemala
- Guernsey
- Guinea
- Guinea-Bissau
- Guyana
- Haiti
- Honduras
- Hong Kong SAR
- Hungary
- Iceland
- India
- Indonesia
- Iran
- Iraq
- Ireland
- Isle of Man
- Israel
- Italy
- Ivory Coast
- Jamaica
- Japan
- Jersey
- Jordan
- Kazakhstan
- Kenya
- Kosovo
- Kuwait
- Kyrgyzstan
- Laos
- Latvia
- Lebanon
- Lesotho
- Liberia
- Libya
- Liechtenstein
- Lithuania
- Luxembourg
- Macao SAR
- Madagascar
- Malawi
- Malaysia
- Maldives
- Mali
- Malta
- Mauritania
- Mauritius
- Mexico
- Moldova
- Monaco
- Mongolia
- Montenegro
- Montserrat
- Morocco
- Mozambique
- Myanmar
- Namibia
- Nepal
- Netherlands
- New Caledonia
- New Zealand
- Nicaragua
- Niger
- Nigeria
- North Macedonia
- Northern Mariana Islands
- Norway
- Oman
- Pakistan
- Palestine
- Panama
- Papua New Guinea
- Paraguay
- Peru
- Philippines
- Poland
- Portugal
- Puerto Rico
- Qatar
- Republic of the Congo
- Romania
- Russia
- Rwanda
- Saint Helena
- Saint Lucia
- Saint Vincent and the Grenadines
- San Marino
- Sao Tome and Principe
- Saudi Arabia
- Senegal
- Serbia
- Seychelles
- Sierra Leone
- Singapore
- Slovakia
- Slovenia
- Somalia
- South Africa
- South Korea
- South Sudan
- Spain
- Sri Lanka
- Sudan
- Suriname
- Svalbard and Jan Mayen
- Swaziland
- Sweden
- Switzerland
- Syria
- Taiwan
- Tajikistan
- Tanzania
- Thailand
- Timor Leste
- Togo
- Tonga
- Trinidad and Tobago
- Tunisia
- Turkey
- Turkmenistan
- U.S. Virgin Islands
- USA
- Uganda
- Ukraine
- United Arab Emirates
- United Kingdom
- Uruguay
- Uzbekistan
- Venezuela
- Vietnam
- Yemen
- Zambia
- Zimbabwe