Human waste and pollution

As the human population grows, more people need resources such as food, water and materials. Rising standards of living can also increase the resources used and the waste produced per person. If waste and chemical materials are not handled properly, they can enter the environment and cause pollution.

Pollution of water, air and land

Pollution can affect different parts of the environment:

• Water can be polluted by sewage, fertiliser washed off land and toxic chemicals released into rivers or other bodies of water.
• Air can be polluted by smoke and acidic gases released into the atmosphere.
• Land can be polluted by waste in landfill sites and by toxic chemicals, particularly if they escape into the surrounding soil.

Pollution can kill plants and animals in affected habitats. If species are lost from a habitat, its biodiversity—the variety of living organisms present—is reduced.