What is pollution? Definition and examples

Pollution refers to the presence of a substance or substances in the environment that are harmful or toxic. The substances or pollutants may be harmful to human health, other animals, and plants. When something harmful enters the environment at a faster rate that it can be dispersed, there is pollution.

Pollutants may be natural or anthropogenic. If something is anthropogenic, it originates from human activity. Volcanic ash, for example, is a natural pollutant, while fumes from vehicles are the result of human activity.

Pollutants damage the land, water, and air. In other words, they damage our environment.

National Geographic has the following definition of the term:

“Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants.”

Pollution causes global warming image
Global warming refers to the rise in the average temperatures of Earth’s oceans and atmosphere.

Etymology of pollution

Etymology is the study of the origin of words and how their meanings and usages have evolved.

The term emerged in the English language in the mid-fourteenth century. However, it did not mean the same then as it does today. In the fourteenth century, it meant “discharge of semen other and during sex.” In the late fourteenth century, it also meant “defilement, desecration.”

The word came from the Late Latin word Pollutionem (nominative pollutio), which meant “defilement.”

It was not until circa 1860 that pollution meant “contamination of the environment.” According to the Online Etymology Dictionary, it did not become a common term until about 1955.

Water pollution

Water pollution includes the contamination of groundwater aquifers, rivers, oceans, and lakes. Unsurprisingly, in the majority of cases, the contamination of water today is the result of human activity.

This type of pollution exists when we cannot get rid of contaminants in water bodies fast enough. In some cases, we can end up consuming those pollutants without being anywhere near the affected water bodies.

Water pollution image 1
A child in waist-high filthy water in Indonesia. Water pollution is the number one cause of death in many countries across the world. (Image: pelicanwater.com)

Contaminants, for example, can get into the food we eat. We refer to them as ‘food contaminants.’ Many food contaminants cause foodborne illnesses.

In many developing countries across the world, dirty and contaminated water is a major cause of death.

Experts say that the contamination of our waters is the second-most imperative environmental concern, after air pollution.

In economics, there is a term – ‘uneconomic growth‘ – which means GDP growth that causes more harm than good. Contaminated water is a major consequence of uneconomic growth. GDP stands for gross domestic product, i.e., all the goods and services that an economy produces in a specific period.

Air pollution

Some people use the term ‘atmospheric pollution.’ This type includes the release of particulates and chemicals into the atmosphere.

Particulates are microscopic liquid or solid matter that float in the air. The letters PM, when talking about air quality, stand for ‘particulate matter.’

Air pollution image 1
Researchers in Singapore reported that severe air pollution can undermine worker productivity.

Common gasses that we class as pollutants include sulfur dioxide, CFCs, nitrogen oxides, and carbon monoxide. When hydrocarbons and nitrogen oxides react to sunlight, smog and ozone are created.

According to the UK’s Department for Environment Food & Rural Affairs (DEFRA), air pollution can cause both long-term and short-term effects on health. The following groups of people are very concerned about air pollution:

  • People with lung or heart conditions.
  • Caregivers (UK: carers), parents, and healthcare professionals who care for somebody whose health is sensitive to contaminated air.
  • The scientific community.
  • Members of the public who want to know more about contaminants in our atmosphere and why they exist. They may also want to find out what they can do to contribute to its reduction.

Weather can affect air quality

The British Lung Foundation says that the amount of air pollution can change depending on the season and weather. During still, summer weather, for example, it is harder for pollutants in the air to disperse. This is also the case when it is foggy in winter. In such cases, air quality deteriorates significantly.

Land pollution

This includes the deposition of liquid or solid waste material on land. It also includes their deposition underground. In both cases, they contaminate the soil and groundwater, damage our environment, and threaten public health.

Waste material 1
Land pollution leads to the loss of tens of billions of tons of topsoil every year. Topsoil is where most of Earth’s biological soil activity happens. (Image: Wikipedia)

There are three main types of waste materials that contaminate the land:

  • Municipal refuse, which we also call municipal solid waste (MSW). Trash from households and businesses, for example, belongs to this category.
  • Construction and demolition debris or waste. This category includes wood, concrete rubble, asphalt, and metal objects.
  • Hazardous waste. This type of waste includes chemicals from petroleum refineries, smelters, dry cleaners, car workshops, and sewage leaks. There are many other sources of hazardous waste.

Light pollution

We also call it photopollution. It includes the presence of light that humans have created in the night environment. In other words, artificial light.

Artificial light has helped accelerate economic growth and make us all more prosperous. However, too much or inappropriate night light can damage our health as well as the health of animals and plants. When that happens, we refer to it as light pollution.

Coastal light Image
Coastal light pollution is attracting some and discouraging other species of marine invertebrates, a study found. (Image: Southampton, Wikipedia)

Wikipedia says the following about photopollution:

“It is exacerbated by excessive, misdirected or obtrusive uses of light, but even carefully used light fundamentally alters natural conditions. As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments.”

Photopollution can be the cause of worker fatigue, decrease in sexual function, heightened anxiety. It can also make people have headaches more often.

The following quote comes from the American Academy of Sleep Medicine:

Inappropriate or excessive use of artificial, outdoor light at night, referred to as “light pollution,” has emerged as a novel environmental factor linked to human health.”

“Research has shown that artificial nighttime lighting, whether indoor or outdoor, induces disruption of circadian rhythms, potentially leading to metabolic and chronic diseases, including cancer, diabetes, obesity and depression.”