Singapore haze: Air quality improves as 24-hour PSI readings in three regions drop out of unhealthy band

SINGAPORE: Air quality improved across Singapore on Sunday (Oct 25), with the 24-hour Pollutant Standards Index (PSI) readings in two regions dropping into the good to moderate band.

The reading in the south dropped out of the unhealthy range at 10am when it dipped to 100, and that in the north followed at 1pm as it fell to 99. At 3pm, the readings in the south and north were in the moderate range.

Readings in western, central and eastern Singapore were also declining but remained in the unhealthy band.

Hourly PM2.5 readings, meanwhile, were in the normal band in all five regions.

On Saturday, the National Environment Agency (NEA) said the 24-hour PSI for Sunday was expected to range from 80 to 130, spanning the good to moderate and unhealthy bands.

In its Sunday morning advisory, NEA said that scattered hotspots were detected in Kalimantan, while moderate to dense smoke plumes were observed to emanate from hotspot clusters in larger parts of Kalimantan, central Sulawesi and southern Papua.

Though the hotspot and smoke haze situation may improve in areas experiencing showers, it may continue to stay elevated in areas experiencing prolonged periods of dry weather, "with a continued risk of transboundary haze occurrence", NEA said.

NEA has advised the public to refer to the 24-hour PSI forecast when planning outdoor activities and to check the latest 1-hour PM2.5 readings before undertaking immediate outdoor activities.

When hourly PM2.5 concentrations are in the elevated band, healthy individuals should reduce strenuous outdoor activities for the next hour.

Vulnerable groups, including children, elderly people, pregnant women and those with chronic heart or lung conditions, should avoid strenuous outdoor activities during that period.

For Sunday, NEA advised healthy individuals to reduce prolonged or strenuous outdoor physical exertion, while elderly people, pregnant women and children should minimise such activities. 

People with chronic heart or lung disease should avoid prolonged or strenuous outdoor physical exertion.