What are the health effects of breathing polluted air?

In one line

The rule

Air pollution is the presence of harmful substances in the air we breathe, which can adversely affect human health and the environment. (CBSE Class 7, 8, 9)

Let's understand it simply

Imagine you are playing cricket on a busy road in Delhi during Diwali. The air is full of smoke from crackers and vehicles. You start coughing, your eyes water, and it feels hard to breathe. This is because the air is not just air—it is mixed with tiny harmful things called pollutants (bad substances like smoke, dust, and gases).

Think of your lungs as a kitchen sponge. When you breathe clean air, the sponge soaks up only water. But if the water is dirty, the sponge gets clogged and dirty too. In the same way, polluted air fills your lungs with harmful things that can make you sick.

How it works

1. You breathe in air through your nose and mouth.
2. If the air has pollutants (like smoke, dust, or harmful gases), these enter your windpipe and lungs.
3. Tiny particles (like PM2.5) go deep into your lungs and even into your blood.
4. Gases like carbon monoxide (CO) and sulphur dioxide (SO₂) mix with your blood and can stop oxygen from reaching your organs.
5. Over time, this damages your lungs, heart, and other parts of your body, causing health problems.

The story behind it

Scientists noticed that people living in cities with lots of smoke and dust were getting sick more often. In the 1950s, London had a deadly event called the "Great Smog," where thousands died because the air was full of smoke from burning coal. This made doctors and scientists study how polluted air harms our health. Today, we know much more about which pollutants are dangerous and how they affect us.

Where you see it in real life

• Delhi during Diwali: Firecrackers release smoke and chemicals → People cough, get sore throats, and asthma attacks increase.
• Busy traffic jams: Vehicles release exhaust gases → People nearby may feel headaches, dizziness, or breathing problems.
• Factories near towns: Factories release smoke and dust → Villagers and workers may develop lung diseases.
• Burning garbage: Open burning of waste releases toxic fumes → Children and elders nearby may get eye irritation and chest pain.
• Indoor cooking with wood or coal: Smoke fills the kitchen → Women and children may develop chronic cough and lung problems.
• Smog in winter: Cold air traps pollution near the ground → More people visit hospitals with breathing trouble.

Why it matters

• Health: Polluted air can cause asthma, bronchitis, heart attacks, strokes, and even cancer.
• Children and elders: They get sick more easily because their bodies are weaker.
• Missed school and work: Sick people cannot go to school or work, affecting families and the economy.
• Long-term damage: Even if you do not get sick right away, breathing polluted air for years can shorten your life.

Worked example

Let's see how air pollution affects a 10-year-old student:

Given: Student breathes air with high PM2.5 (tiny dust) for 2 hours during Diwali.
Step 1: Polluted air enters lungs with every breath.
Step 2: PM2.5 particles reach deep into the lungs.
Step 3: These particles cause irritation and swelling in the airways.
Step 4: Student starts coughing and feels chest tightness.
Step 5: If the student has asthma, an attack can happen, needing medicine or a hospital visit.

Common mistakes

• Thinking only factories cause air pollution: Vehicles, burning garbage, and even indoor stoves can pollute air.
• Believing only lungs are affected: Polluted air can also harm the heart, brain, and even unborn babies.
• Assuming short exposure is safe: Even a few hours of heavy pollution can trigger asthma or heart problems in sensitive people.
• Ignoring indoor air pollution: Cooking with wood or coal indoors is as dangerous as outdoor pollution.

Remember it

If the air looks dirty or smells bad, it is harming your body—protect yourself and avoid it when you can.