KUALA LUMPUR, July 21 -- The number of areas in peninsular Malaysia recording unhealthy air quality has doubled overnight, based on readings from the Environment Department's Air Pollutant Index Management System (APIMS).

As of 9am today, eight locations recorded Air Pollutant Index (API) readings above 100.

The worst hit was Alor Gajah in Melaka, with an API reading of 160.

The other seven areas with unhealthy air were listed as:

An API reading between 0 and 50 indicates good air quality, 51 to 100 is moderate, 101 to 200 is unhealthy, 201 to 300 is very unhealthy, and above 300 is hazardous.

Moderate air quality was detected in 57 areas nationwide.

Environment Department director-general Wan Abdul Latiff Wan Jaafar yesterday said ...