Consequences of Polluted Air

1How polluted air harms our health

Polluted air enters the body through the respiratory system: the nose, the windpipe and the lungs. So these are harmed first.

• Coughing, sore throats and stinging eyes.
• Asthma attacks: the airways tighten and breathing becomes hard.
• Bronchitis and pneumonia: infections of the airways and lungs. Young children who breathe smoke are especially at risk.
• Lung cancer, heart disease and stroke after many years of breathing dirty air.
• Carbon monoxide poisoning: headache, sleepiness and even death in a closed room.

What about tuberculosis (TB)? TB is caused by germs (bacteria) that spread through the air when a sick person coughs or sneezes. Smoke does not create the TB germ, but it weakens the lungs. People who breathe smoke every day, from tobacco or from cooking fires, are more likely to catch TB and to become very sick from it. Crowded rooms with little fresh air also help TB germs spread.

Air pollution is one of the world's leading causes of illness. It is blamed for millions of deaths every year, and death rates are highest in low- and middle-income countries. The good news is that these death rates have been falling, mostly because more families now cook with cleaner fuels and stoves.

2How polluted air harms our planet

Global warming. Some gases in the air, such as carbon dioxide, act like the glass of a greenhouse: they let sunlight in but trap some of the heat. This natural greenhouse effect keeps the Earth warm enough to live on. But burning fuels adds extra carbon dioxide, so more heat is trapped and the Earth's temperature rises. This is global warming, and it changes the climate: heavier rains that cause floods and landslides on hillsides, and longer droughts in dry areas.

Acid rain. Sulphur dioxide and nitrogen oxides dissolve in rain and make it acidic. Acid rain damages leaves, soil, lakes, metal roofs and buildings.

Damage to plants and animals. Soot covering leaves blocks sunlight, so plants make less food and crops grow less. Animals breathe the same dirty air that we do.

Accidents. Thick smoke and haze make it hard for drivers to see.

Worked example: who is most at risk?

Think about who spends the most time near the pollution:

• A baby tied on its mother's back while she cooks breathes the kitchen smoke for hours every day, with small, still-growing lungs.
• A grandmother who has cooked over an open fire for forty years has breathed smoke for most of her life.
• A moto driver in Kigali traffic breathes exhaust fumes all day.
• A child with asthma reacts to even a little smoke.

So the people most at risk are babies and young children, older people, people with asthma, and the people (often women and girls) who cook over open fires.

Try it yourself

Try each one first, then tap Show answer to check.