FOR two months his year, the first thing many of us checked in the morning was not the weather or the traffic but the Air Pollutant Index (API).

Parents decided whether their children could play outside. Schools called off outdoor activities. Then the haze lifted, and most of us stopped checking.

The air did not suddenly become clean. It simply stopped being visible. Haze is the pollution we notice but the air we breathe on an ordinary day is shaped by everyday choices: how we travel, how factories run and how we get rid of rubbish.

If we act only when the sky turns grey, we will keep treating the symptoms while ignoring the cause.