What are the causes of air pollution?

The causes of air pollution are both natural and human. Pollution of the air happens both outside and inside our houses.

2020 Smoke from bushfires over Sydney, Australia ©iStock

2020 Smoke from bushfires over Sydney, Australia ©iStock

Outdoors Causes

  • Natural causes of air pollution include smoke and a gas called carbon monoxide that is released by bushfires.

  • Wind erosion blows soil into the air in places where there are few plants to hold the soil together.

  • Pollen is dispered from plants and into the air.

  • Methane is a gas produced by farm animals as they digest their food. The animals belch and fart the gas into the air. 

  • Methane is also produced by the natural rotting of plants and from our rotting garbage in rubbish dumps.

  • Radon, a gas from radioactive decay within the Earth's crust, pollutes the air.

  • Erupting volcanoes release the poisonous gases sulfur and chlorine, and blow ash particulates into the air.

Exhaust fumes from cars and other motor vehicles are a major cause of air pollution. ©iStock

Exhaust fumes from cars and other motor vehicles are a major cause of air pollution. ©iStock

Fossil fuels

Probably the main human cause of air pollution is the burning of fossil fuels such as coal, and petrol. Coal is burned to make electricity at power plants and harmful gases are released as this happens. When they are burned, these fuels cause smog (a mixture of fog and smoke), acid rain, and soot. 

Some pollutants make their way up into the upper atmosphere, causing a thinning of the protective ozone layer. This has led to changes in the environment and increases in skin cancers in humans.

Air pollution also causes acid rain. 

Rainwater picks up particles and gases when it falls through the air.  If the air is polluted, the rainwater becomes polluted too. Acid rain damages trees, crops, other plants, lakes, and the animals that live on the land and in the water.  Acid rain and air pollution also dirties and damages buildings, monuments, and statues in cities and towns.

Indoors Causes

  • Burning wood inside the house for heat causes smoke pollution.

  • Smoking cigarettes inside the house will cause pollution.

  • Mould that builds up in damp areas in kitchens and bathrooms can cause harmful mould spores to be released into the air. 

Smoke from chimneys mixes with fog to cause smog ©iStock

Smoke from chimneys mixes with fog to cause smog ©iStock

Air pollution and your health

Outdoors, breathing polluted air can make your eyes and nose burn. It can irritate your throat and make breathing difficult. Pollutants such as tiny airborne particles of dust, soot, and smoke can get deep into a person's lungs. This can cause problems for all people, but especially those with asthma, and young people whose bodies are still growing.
Inside, smoke from fires and cigarettes will irritate eyes and throat. Mould spores that grown in damp places will cause runny noses and skin and eye irritations.

The cost of air pollution

The cost of the damage to the environment can be great. Air pollution also reduces farm crops and forests that also costs lots of money in lost food and timber production.

What you can do

Home heating

At home, avoid burning of wood in fireplaces and in stoves. If you do, make sure that the wood for burning is dry. Make sure that the chimney and flue are working well to take away smoke. While the fire is burning make sure there is fresh air coming into the room to avoid the build up of dangerous gases that are released by the fire.
Note: Electric heaters are better than gas. They don't produce any indoor air pollution.

Many chemicals we use inside the house can be harmful. 

  • Only use aerosol sprays and cleaning products in well ventilated rooms. 

  • Turn off lights to save electricity. This means there will be less pollution released into the air from power stations.

  • Use gas for the barbeque. It is less polluting than wood or charcoal.

  • Cycle or walk to school rather than have a parent drive you. 

  • Recycle paper, plastic, glass bottles, cardboard, and aluminum cans. It takes less energy to reuse these things than it does to make new ones from raw materials. Recycling conserves energy and reduces emissions from factories.

Can you think of other ways to reduce your contribution to air pollution?

Watch a video about air pollution

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