Pollution is the introduction of harmful materials into
the environment. These harmful materials are called
pollutants. Pollutants can be natural, such as volcanic
ash. They can also be created by human activity, such
as trash or runoff produced by factories. Pollutants
damage the quality of air, water, and land.
Many things that are useful to people produce
pollution. Cars spew pollutants from their exhaust
pipes. Burning coal to create electricity pollutes the
air. Industries and homes generate garbage and
sewage that can pollute the land and water. Pesticides
– chemical poisons used to kill weeds and insects –
seep into waterways and harm wildlife.
All living things – from one-celled microbes to blue
whales – depend on Earth's supply of air and water.
When these resources are polluted, all forms of life
Pollution is a global problem. Although urban areas
are usually more polluted than the countryside,
pollution can spread to remote places where no
people live. For example, pesticides and other
chemicals have been found in the Antarctic ice sheet.
In the middle of the northern Pacific Ocean, a huge
collection of microscopic plastic particles forms what
is known as the Great Pacific Garbage Patch.
Air and water currents carry pollution. Ocean currents
and migrating fish carry marine pollutants far and
wide. Winds can pick up radioactive material
accidentally released from a nuclear reactor and
scatter it around the world. Smoke from a factory in
one country drifts into another country.
Adapted from: https://www.nationalgeographic.org/encyclopedia/pollution. Accessed on March 27, 2021.