What is air pollution? Definition and examples

Air pollution includes the release of chemicals and particulates into the atmosphere. We also call it atmospheric pollution. Some gasses that we class as pollutants include nitrogen oxides, CFCs, sulfur dioxide, and carbon monoxide. The letters CFCs stand for chlorofluorocarbons.

When nitrogen oxides and hydrocarbons react to sunlight, they create ozone and smog.

The Environmental Pollution Centers defines atmospheric pollution as:

The presence of toxic chemicals or compounds (including those of biological origin) in the air, at levels that pose a health risk.”

“In an even broader sense, air pollution means the presence of chemicals or compounds in the air which are usually not present and which lower the quality of the air or cause detrimental changes to the quality of life (such as the damaging of the ozone layer or causing global warming).”

Air pollution is one type of pollution

Pollution refers to the presence of substances in the environment that are harmful or toxic. Toxic means poisonous. The substances, which we refer to as ‘pollutants,’ may be harmful to human health. May may also be harmful to other animals as well as plants.



Pollution exists when something harmful enters the environment faster than it can be dispersed.

The three main types are water, air, and land pollutionWater pollution refers to the contamination of, for example, oceans, groundwater, aquifers, lakes, and rivers.

Air Pollution - Beijing
Beijing, China’s capital, in 2005. (Left) after rain, and (right) on a smoggy day. (Image: Wikipedia)

Air pollution and the weather

According to the British Lung Foundation, air pollution levels can change depending on the weather and time of year.

In the summer, for example, on a still day, it is more difficult for airborne pollutants to disperse. Therefore, concentrations of particulates or toxic substances tend to rise significantly. In foggy winter days, air quality can deteriorate for the same reason.

Air pollution – the result of human activity

In most cases, air pollutants are anthropogenic. In other words, they originate from human activity. Some air pollutants may be natural. Volcanoes, for example, emit natural pollutants into the atmosphere when they erupt.

Human activities such as construction, transportation, industrial production, and mining pollute our atmosphere significantly. Agriculture is also responsible for some airborne pollutants.

Anthropogenic pollutants, unlike natural ones, do not come and go. In fact, emissions from human activity tend to get progressively worse.

Cyclist wearing mask - air pollution
In many cities, cyclists wear masks. According to Bike Shack: “The best and only cycling masks you should consider purchasing are ones which have sub micron filters that catch even the smallest of pollution particles.” (Image: bikeshackleyton.com)

Air pollution – human health

Air pollution harms all of us; some more than others. People who live in big cities often experience irritation of the respiratory tract. Some may also have a cough, runny nose, and itchy eyes when air quality is particularly bad.

For older adults, babies, young children, and people with asthma, however, air pollution can be life-threatening. People with chronic lung diseases have to stay indoors when air pollution levels are high.



Air pollution - children
Air pollution can seriously damage children’s health. (Image: British Lung Foundation)

Some studies have linked atmospheric pollution with a higher risk of developing cardiovascular diseases and several cancers.

According to the World Health Organization:

“Ambient (outdoor air pollution) is a major cause of death and disease globally. The health effects range from increased hospital admissions and emergency room visits, to increased risk of premature death.”

“An estimated 4.2 million premature deaths globally are linked to ambient air pollution, mainly from heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections in children.”

Elderly - air pollution
Elderly people are especially vulnerable to air pollution because: 1. They have been exposed to pollutants for a long time. 2. Their bodies take longer to get rid of toxins. (Images: pexels.com)

Cause of deaths

The World Health Organization says that globally, air pollution accounts for:



  • 43% of all deaths and disease from COPD (chronic obstructive pulmonary disease).
  • 25% of all deaths and diseases from ischemic heart disease. Ischemic heart disease refers to heart problems caused by narrowed heart arteries.
  • 24% of all deaths from stroke.
  • 17% of all deaths from acute lower respiratory infection.
  • 29% of all deaths and disease from lung cancer.

Air pollution – worker productivity

A recent study found that severe air pollution can reduce worker productivity. Researchers from the National University of Singapore spent over a year gathering and analyzing data from some Chinese factories. They also interviewed factory managers.

Liu Haoming, an Associate Professor in the Department of Economics, said:

“We found that an increase in PM2.5, by 10 micrograms per cubic meter sustained over 25 days, reduces daily output by 1 percent, harming firms and workers. The effects are subtle but highly significant.”

“High levels of particles are visible and might affect an individual’s well-being in a multitude of ways. Besides entering via the lungs and into the bloodstream, there could also be a psychological element.”

“Working in a highly polluted setting for long periods of time could affect your mood or disposition to work.”