The Pollutant Standard Index (PSI) in Brunei Darussalam yesterday dropped to 66 as of 5pm even as the air quality in towns in the neighbouring Malaysian state of Sarawak remained unhealthy.
Air quality and visibility worsened on Borneo as smoke continued to billow from Indonesia, officials said.
The Air Pollutant Index -- which deems levels of 101-200 to be unhealthy -- reached 120 in Kuching, the capital of Sarawak state, a Department of Environment official told AFP.
The index edged higher to 110 in oil-rich Bintulu and 148 and 114 in the towns of Smarahan and Sri Aman.
Visibility dropped to below 1.5 kilometres (0.9 miles) in Kuching, 2.5 kilometres in Sri Aman and 3.0 kilometres in Bintulu. Normal levels are more than 10 kilometres.
An official from the forecast unit of the Meteorological Department told AFP that farmers in neighbouring Indonesia preferred to burn forests and other land for planting crops at this season.
"This is the south-west monsoon season, it is always dry so they prefer to burn at this time rather than during the rainy season," he said.
"The situation in Malaysia hasn't been so bad this year because of the rain which causes the haze to subside a little," he said.
Courtesy of Borneo Bulletin