Look at Fig. 3.3a and Fig. 3.3b. Which playground would you like to play in, and why? (a) (b) Fig. 3.3, page 31 — the two playgrounds, redrawn sketch.

The playground in Fig. 3.3a — because it is clean, well-maintained and looks beautiful , while the one in Fig. 3.3b is polluted, dirty, unhygienic and full of flies and mosquitos. The reason is not only that the clean one looks nicer. A dirty playground is a health risk, and the chapter explains why: Mosquitos breeding in standing water are vectors — they carry malaria and dengue. Houseflies sitting on waste and then on food carry the pathogens of typhoid, cholera and other food- and water-borne diseases. Dust and smoke in such places make breathing difficult and can bring on coughing or asthma. That is why the book concludes: people living in such areas may fall sick more often . Why it happens: keeping ourselves clean protects only us. Keeping the surroundings clean removes the place where the vector breeds — and that protects everybody who uses the ground. This is why the chapter puts “keep the environment clean” on the same footing as personal hygiene.

NCERT Solutions for Class 8th Science Chapter 3 Activity 3.3: Let us compare — Keep the environment clean

Book page 31 Updated on2026-09-19

Q1.

Look at Fig. 3.3a and Fig. 3.3b. Which playground would you like to play in, and why?

Fig. 3.3, page 31 — the two playgrounds, redrawn sketch.

Answer

The playground in Fig. 3.3a — because it is clean, well-maintained and looks beautiful, while the one in Fig. 3.3b is polluted, dirty, unhygienic and full of flies and mosquitos.

The reason is not only that the clean one looks nicer. A dirty playground is a health risk, and the chapter explains why:

Mosquitos breeding in standing water are vectors — they carry malaria and dengue.
Houseflies sitting on waste and then on food carry the pathogens of typhoid, cholera and other food- and water-borne diseases.
Dust and smoke in such places make breathing difficult and can bring on coughing or asthma.

That is why the book concludes: people living in such areas may fall sick more often.

Why it happens: keeping ourselves clean protects only us. Keeping the surroundings clean removes the place where the vector breeds — and that protects everybody who uses the ground. This is why the chapter puts “keep the environment clean” on the same footing as personal hygiene.

Q2.

Have you ever found it hard to breathe in a place with a lot of smoke or dust?

Answer

Yes — most of us have, standing near a rubbish fire, a busy road or a dusty construction site. It happens because clean air and water are important for our health.

Smoke and dust are made of tiny solid particles. When we breathe them in, the lining of the airways is irritated. The body responds by coughing (to throw the particles out) and by narrowing the airways, which is what makes breathing feel hard.

In cities, air pollution from vehicles and factories can cause problems like coughing or asthma.
The Air Quality Index (AQI) helps us know how clean the air is on a given day.
A cleaner environment helps us stay healthy and feel better.

Check it yourself: look up today’s AQI for your town. A low number means clean air; a high number means the air carries a heavy load of particles, and outdoor exercise is better postponed to a cleaner day.

Was this helpful?