For instance, during a period of Haze, where the Air Quality Index can deteriorate significantly and fast, the published Air Pollution index is most likely lower than the actual pollution. Similarly, when the air polution decreases, the Air Quality Index can still be very high although the pollution is gone.Read more here.
Luchtkwaliteitsgegevens verstrekt door: the Malaysia Department of Environment (DOE); Air Polluant Index Management System (eqms.doe.gov.my)