Air pollution

Air pollution from a coking oven
2016 air quality indicator – light colors have lower air quality and thus higher air pollution.
Aviation is a major source of air pollution.
Controlled burning of a field outside of Statesboro, Georgia, in preparation for spring planting
Smoking of fish over an open fire in Ghana, 2018
Dust storm approaching Stratford, Texas
Beijing air in 2005 after rain (left) and a smoggy day (right)
E-waste processing in Agbogbloshie, Ghana using open-burning of electronics to access valuable metals like copper. Open burning of plastics is common in many parts of the world without the capacity for processing. Especially without proper protections, heavy metals and other contaminates can seep into the soil, and create water pollution and air pollution.
Schematic drawing, causes and effects of air pollution: (1) greenhouse effect, (2) particulate contamination, (3) increased UV radiation, (4) acid rain, (5) increased ground-level ozone concentration, (6) increased levels of nitrogen oxides
Up to 30% of Europeans living in cities are exposed to air pollutant levels exceeding EU air quality standards. Around 98% of Europeans living in cities are exposed to levels of air pollutants deemed damaging to health by the World Health Organization's more stringent guidelines.
Share of deaths from indoor air pollution
Air quality monitoring, New Delhi, India
Share of deaths from outdoor air pollution, OWID
Comparison of footprint-based and transboundary pollution-based relationships among G20 nations for the number of PM2.5-related premature deaths.
Unprotected exposure to PM2.5 air pollution can be equivalent to smoking multiple cigarettes per day, potentially increasing the risk of cancer, which is mainly the result of environmental factors.
Share of the population exposed to air pollution levels above WHO guidelines, OWID
Artist's illustration of an advanced ET civilization with industrial pollution
Support for a ban on high-emission vehicles in city centres in Europe, China and the US from respondents to the European Investment Bank Climate Survey
Support, use and infrastructure-expansion of forms of public transport that do not cause air pollution may be a critical key alternative to pollution
Tarps and netting are often used to reduce the amount of dust released from construction sites.
Smog in Cairo
Nitrogen dioxide concentrations as measured from satellite 2002–2004
Deaths from air pollution in 2004
Before flue-gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.
Thermal oxidisers are air pollution abatement options for hazardous air pollutants (HAPs), volatile organic compounds (VOCs), and odorous emissions.

Contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials.

- Air pollution

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Natural environment

Built environment.

Land management has preserved the natural characteristics of Hopetoun Falls, Australia while allowing ample access for visitors.
An image of the Sahara desert from satellite. It is the world's largest hot desert and third-largest desert after the polar deserts.
A volcanic fissure and lava channel
Earth's layered structure: (1) inner core; (2) outer core; (3) lower mantle; (4) upper mantle; (5) lithosphere; (6) crust
Coral reefs have significant marine biodiversity.
Rocky stream in the U.S. state of Hawaii
Lácar Lake, of glacial origin, in the
A swamp area in Everglades National Park, Florida, US.
Atmospheric gases scatter blue light more than other wavelengths, creating a blue halo when seen from space.
A view of Earth's troposphere from an airplane
Lightning is an atmospheric discharge of electricity accompanied by thunder, which occurs during thunderstorms and certain other natural conditions.
The retreat of glaciers since 1850 of Aletsch Glacier in the Swiss Alps (situation in 1979, 1991 and 2002), due to global warming
Another view of the Aletsch Glacier in the Swiss Alps, which because of global warming has been decreasing
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere.
There are many plant species on the planet.
An example of the many animal species on the Earth
Rainforests often have a great deal of biodiversity with many plant and animal species. This is the Gambia River in Senegal's Niokolo-Koba National Park.
Old-growth forest and a creek on Larch Mountain, in the U.S. state of Oregon
Map of terrestrial biomes classified by vegetation
Chloroplasts conduct photosynthesis and are found in plant cells and other eukaryotic organisms. These are chloroplasts visible in the cells of Plagiomnium affine — many-fruited thyme-moss.
A conifer forest in the Swiss Alps (National Park)
The Ahklun Mountains and the Togiak Wilderness within the Togiak National Wildlife Refuge in the U.S. state of Alaska
A view of wilderness in Estonia
Before flue-gas desulfurization was installed, the air-polluting emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.
Amazon rainforest in Brazil. The tropical rainforests of South America contain the largest diversity of species on Earth, including some that have evolved within the past few hundred thousand years.

The massive environmental changes of humanity in the Anthropocene have fundamentally effected all natural environments: including from climate change, biodiversity loss and pollution from plastic and other chemicals in the air and water.


Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air.

This diagram shows types, and size distribution in micrometres (μm), of atmospheric particulate matter.
PM2.5 and PM10 compared with a human hair in a graphic from the Environmental Protection Agency
2005 radiative forcings and uncertainties as estimated by the IPCC.
Global aerosol optical thickness. The aerosol scale (yellow to dark reddish-brown) indicates the relative amount of particles that absorb sunlight.
Particulates in the air causing shades of grey and pink in Mumbai during sunset
Solar radiation reduction due to volcanic eruptions
Air pollution measurement station in Emden, Germany
Deaths from air pollution compared to other common causes
Air quality information on PM10 displayed in Katowice, Poland
Air quality trends in the United States
Air quality trends in the western United States
Air quality trends in the southwestern United States
Concentration of PM10 in Europe

Particulates are the most harmful form (other than ultra-fines) of air pollution due to their ability to penetrate deep into the lungs, blood streams and brain, causing health problems including heart attacks, respiratory disease, and premature death.


Externality or external cost is an indirect cost or benefit to an uninvolved third party that arises as an effect of another party's activity.

Air pollution from motor vehicles is an example of a negative externality. The costs of the air pollution for the rest of society is not compensated for by either the producers or users of motorized transport.
Graph of Positive Externality in Production
Light pollution is an example of an externality because the consumption of street lighting has an effect on bystanders that is not compensated for by the consumers of the lighting.
Negative production externality
Negative consumption externality
Positive production externality
Positive consumption externality
Demand curve with external costs; if social costs are not accounted for price is too low to cover all costs and hence quantity produced is unnecessarily high (because the producers of the good and their customers are essentially underpaying the total, real factors of production.)
Supply curve with external benefits; when the market does not account for the additional social benefits of a good both the price for the good and the quantity produced are lower than the market could bear.
"Relative percentage price [∆] increases for broad categories [...] when externalities of greenhouse gas emissions are included in the producer's price."

Air pollution from motor vehicles is one example.

Chronic obstructive pulmonary disease

Type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation.

Section of a lung showing centrilobular emphysema, with enlarged airspaces in the centre of a lobule usually caused by smoking and a major feature of COPD
Signs and symptoms of stages of COPD.
Access to clean fuel and clean cooking facilities as of 2016.
Normal lungs shown in upper diagram. Lungs damaged by COPD in lower diagram with an inset showing a cross-section of bronchioles blocked by mucus, and damaged alveoli.
Micrograph showing emphysema (left – large empty spaces) and lung tissue with relative preserved alveoli (right).
A person blowing into a spirometer. Smaller handheld devices are available for office use.
Chronic obstructive pulmonary disease deaths per million persons in 2012
Giovanni Battista Morgagni, who made one of the earliest recorded descriptions of emphysema in 1769
alt=A black and white image, with a small white heart in the middle and large black lungs around it|Chest X-ray demonstrating severe COPD: Note the small heart size in comparison to the lungs.
A lateral chest X-ray of a person with emphysema: Note the barrel chest and flat diaphragm.
Lung bulla as seen on chest X-ray in a person with severe COPD
A severe case of bullous emphysema
Axial CT image of the lung of a person with end-stage bullous emphysema
Very severe emphysema with lung cancer on the left (CT scan)

Other risk factors include indoor and outdoor pollution, exposure to occupational irritant substances such as dust from grains, cadmium dust or fumes, alpha1-antitrypsin deficiency, being an older man, and genetics.

Lung cancer

Malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung.

A chest X-ray showing a tumor in the lung (marked by arrow)
Relationship between cigarette consumption per person (blue) and male lung cancer rates (dark yellow) in the US over the century
Risk of death from lung cancer is strongly correlated with smoking.
CT scan showing a cancerous tumor in the left lung
Primary pulmonary sarcoma in an asymptomatic 72-year-old male
Pie chart showing incidences of NSCLCs as compared to SCLCs shown at right, with fractions of smokers versus nonsmokers shown for each type
Cross section of a human lung: The white area in the upper lobe is cancer; the black areas are discoloration due to smoking.
Pneumonectomy specimen containing a squamous-cell carcinoma, seen as a white area near the bronchi
Brachytherapy (internal radiotherapy) for lung cancer given via the airway
Monoclonal antibodies used in the treatment of NSCLC and their mechanism of action
The main treatment arms of phase 3 clinical trials providing immunotherapy in the first line for patients with NSCLC
Overall survival in NSCLC patients treated with protocols incorporating immunotherapy in the first line for advanced or metastatic disease. Nasser NJ, Gorenberg M, Agbarya A. Pharmaceuticals 2020, 13(11), 373;
Lung cancer, incidence, mortality, and survival, England 1971–2011
Stage IA and IB lung cancer
Stage IIA lung cancer
Stage IIB lung cancer
One option for stage IIB lung cancer, with T2b; but if tumor is within 2 cm of the carina, this is stage 3
Stage IIIA lung cancer
Stage IIIA lung cancer, if there is one feature from the list on each side
Stage IIIA lung cancer
Stage IIIB lung cancer
Stage IIIB lung cancer
Stage IV lung cancer

These cases are often caused by a combination of genetic factors and exposure to radon gas, asbestos, second-hand smoke, or other forms of air pollution.

Air quality index

Smog in Shanghai, December 1993—an example of air conditions typically rated as unhealthy
An annotated satellite photo showing smoke from wildfires in Greece, giving rise to an elevated AQI downwind
An air quality measurement station in Edinburgh, Scotland
Signboard in Gulfton, Houston indicating an ozone watch
PM2.5 24-Hour AQI Loop, Courtesy US EPA
A global air quality map

An air quality index (AQI) is used by government agencies to communicate to the public how polluted the air currently is or how polluted it is forecast to become.

Fossil fuel

Hydrocarbon-containing material formed naturally in the earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel.

Since oil fields are located only at certain places on earth, only some countries are oil-independent; the other countries depend on the oil-production capacities of these countries
A petrochemical refinery in Grangemouth, Scotland, UK
An oil well in the Gulf of Mexico
The Global Carbon Project shows how additions to since 1880 have been caused by different sources ramping up one after another.
Global surface temperature reconstruction over the last 2000 years using proxy data from tree rings, corals, and ice cores in blue. Directly observational data is in red, with all data showing a 5 year moving average.
In 2020, renewables overtook fossil fuels as the European Union's main source of electricity for the first time.

Additionally, most air pollution deaths are due to fossil fuel particulates and noxious gases.

Public health

Public health has been defined as "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals".

Example of historical public health recommendations from 1918 in New Haven, Connecticut, United States
Community health workers
The WHO is the predominant agency associated with global health
Newspaper headlines from around the world about polio vaccine tests (13 April 1955)
Three former directors of the Global Smallpox Eradication Program reading the news that smallpox had been globally eradicated, 1980
A village health worker in Zimbabwe conducting a pediatric examination
A community health worker in Korail Basti, a slum in Dhaka, Bangladesh
A malaria test in Kenya. Despite being preventable and curable, malaria is a leading cause of death in many developing nations.
A Cuban doctor performs an open air operation in Guinea-Bissau. Cuba sends more medical personnel to the developing world than all G8 countries combined.
Mass burials during the second plague pandemic (a.k.a. the Black Death; 1346–1353) intensified urban responses to disaster on the basis of earlier practices. Miniature from "The Chronicles of Gilles Li Muisis" (1272–1352). Bibliothèque royale de Belgique, MS 13076–77, f. 24v.
A depiction of Aztec smallpox victims
Sir Edwin Chadwick was a pivotal influence on the early public health campaign.
Early epidemiologist John Snow mapped clusters of cholera cases in London
Paul-Louis Simond injecting a plague vaccine in Karachi, 1898
The London School of Hygiene & Tropical Medicine is the oldest school of public health in the Anglosphere
Ghanaian children receive insecticide-treated bed nets to prevent exposure to malaria transmitting mosquitos

Common public health initiatives include promotion of hand-washing and breastfeeding, delivery of vaccinations, promoting ventilation and improved air quality both indoors and outdoors, suicide prevention, smoking cessation, obesity education, increasing healthcare accessibility and distribution of condoms to control the spread of sexually transmitted diseases.


Degree to which a chemical substance or a particular mixture of substances can damage an organism.

The skull and crossbones is a common symbol for toxicity.
The international pictogram for toxic chemicals.

Air: particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, asbestos, ground-level ozone, lead (from aircraft fuel, mining, and industrial processes)

Cardiovascular disease

Class of diseases that involve the heart or blood vessels.

Micrograph of a heart with fibrosis (yellow) and amyloidosis (brown). Movat's stain.
Calcified heart of an older woman with cardiomegaly
Density-Dependent Colour Scanning Electron Micrograph SEM (DDC-SEM) of cardiovascular calcification, showing in orange calcium phosphate spherical particles (denser material) and, in green, the extracellular matrix (less dense material)
Cardiovascular diseases deaths per million persons in 2012

There are many risk factors for heart diseases: age, sex, tobacco use, physical inactivity, non-alcoholic fatty liver disease, excessive alcohol consumption, unhealthy diet, obesity, genetic predisposition and family history of cardiovascular disease, raised blood pressure (hypertension), raised blood sugar (diabetes mellitus), raised blood cholesterol (hyperlipidemia), undiagnosed celiac disease, psychosocial factors, poverty and low educational status, air pollution, and poor sleep.