Mystery #4Tier 2air pollution
What actually is air pollution, and why does breathing clean air matter so much?
Air can be clean and fresh, or thick, hazy, and hard to breathe. We call the bad kind air pollution. But what is actually mixed into polluted air, and why does breathing clean air matter so much?
Your guess
What's your hunch? What do you think is actually in polluted air, and why might it harm you?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.