Pollution – iGCSE Biology CAIE Revision

Understanding Pollution

Pollution refers to the introduction of harmful substances or products into the environment.
These pollutants can take various forms, including chemicals, energy (such as noise, heat, or light), or waste materials.
Pollution can occur naturally, for example, from volcanoes or forest fires, but it is often caused by human activities.

Air Pollution: Caused by the release of pollutants such as sulphur dioxide, carbon monoxide and nitrogen oxides into the atmosphere. Common sources include vehicle exhaust, power plants, and industrial processes.
Water Pollution: The contamination of water bodies (rivers, lakes, oceans) usually caused by human activities. Pollutants include sewage, oil spills, and agricultural runoff containing pesticides and fertilisers.
Soil Pollution: Also known as land pollution, it is the result of hazardous waste being dumped and chemical spills which can change the soil’s natural composition.
Noise Pollution: Often overlooked, this type of pollution refers to disruptive, excessive noise that can harm human or animal life.
Light Pollution: Excessive, misdirected, or obtrusive artificial light is a significant problem, particularly in urbanised regions. It can disrupt ecosystems and natural habitats.

Pollution can significantly damage the natural environment and the organisms that live in it.
Many forms of pollution have the potential to disrupt the ecosystems, kill plants and animals, or cause significant health problems in humans.
Species that cannot adapt quickly to changes brought on by pollution may become endangered or extinct.
Pollution often disproportionately affects disadvantaged and poorer communities, leading to a concept called environmental justice.

Many types of pollution can be prevented or reduced through careful planning, the use of technology, laws and regulations.
For instance, air pollution can be reduced by using cleaner sources of energy, while water pollution can be mitigated by better waste management systems.
Individuals can also play a role in tackling pollution through small actions such as recycling, reducing energy consumption, and using public transportation.

There are numerous international agreements in place designed to control pollution such as the Kyoto Protocol and Paris Agreement targeting greenhouse gas emissions which lead to climate change.
Such agreements can facilitate global efforts in reducing pollution and managing resources sustainably.