API readings based on 24-hour average, says DOE

PETALING JAYA: Air Pollutant Index (API) readings are based on a 24-hour average, said the Department of Environment (DOE).

Following queries about Saturday’s API readings for the Klang Valley, the DOE said certain areas in the Klang Valley did not post unhealthy air quality readings that day as the average value of Particulate Matter – the fine dust that causes haze – for the past 24 hours was below 150 microgram per cubic metre.