Air pollution is bad news. It can make people and animals sick. But how does the air get polluted? In this lesson, you’ll learn about what causes air pollution.

What is Air Pollution?

When you’re riding in a car, and you see exhaust coming out the back, do you ever wonder what the exhaust is? What’s in it? Why do cars make it? Where does it go when it disappears into the air?

Sadly, the answer isn’t much fun. Car exhaust is full of dangerous chemicals, and it’s one cause of air pollution. Air pollution is dangerous gas or smoke in the air. Some air pollution comes from nature, but most causes of air pollution are things that people do, like driving cars that make exhaust.

Burning Fuel for Cars and Electricity

One big source of air pollution is the fuel we burn to drive our cars and trucks, and to make electricity. All these things use fossil fuels. Fossil fuels include gas, diesel, and coal. Burning fossil fuels lets us drive cars around, but it makes dangerous gasses like:

  • Carbon monoxide. If you breathe in carbon monoxide, it can make you sick.
  • Carbon dioxide. Carbon dioxide is bad for the environment, because it acts like a blanket for the Earth. It makes everything warmer. When the Earth gets warmer, it can be dangerous for animals that need the cold, like polar bears. It can also cause dangerous storms.
  • Sulfur dioxide. If you breathe in air polluted with sulfur dioxide, it hurts your lungs and throat. Sometimes sulfur dioxide gets spread around in the air and falls back to the ground when it rains. Rain full of sulfur dioxide is called acid rain. Acid rain is very dangerous to plants and animals.
Acid rain stripped the leaves off these trees.
Trees damaged by acid rain

When you look at exhaust from a car or truck, you’re looking at dangerous gasses like carbon monoxide. It might look like it’s just disappearing into the air, but it’s not going away. The dangerous chemicals are still there, causing air pollution that makes people sick.

Other Causes of Air Pollution

People also make air pollution in other ways besides burning fossil fuels. Some factories make chemicals, gasses, or smoke that pollutes the air. Air pollution can also come from building and construction materials. Paint remover, insulation that keeps your house warm in the winter, and some chemicals used in dry-cleaning clothes can all cause air pollution. Factories and other sources make 187 kinds of dangerous chemicals that cause air pollution. These chemicals can give people breathing problems, make it hard to have children, and even cause cancer.

When we throw away garbage and the garbage rots, it can also pollute the air with a kind of gas called methane. Raising a lot of cows for beef and dairy also pollutes the air with methane. The cows fart a lot, and their farts have a lot of methane!

If you have trouble remembering all these causes of air pollution, just remember the 3 F’s: Fossil fuels, Factories, and Farts or other Funky-smelling things (like rotting garbage).

This looks like a cloud, but actually, it is air pollution. Would you want to breathe that?
Smog in Australia

Lesson Summary

Air pollution is air that is full of something dangerous, like smoke or chemicals. Air pollution makes people sick. People make air pollution by burning fossil fuels to drive our cars and make electricity. We also make air pollution by releasing dangerous chemicals from factories, building materials, and other sources. Remember the 3 F’s: Fossil fuels, Factories, and Farts or Funky-smelling garbage.