Haze in Singapore: Air quality across the island remains in unhealthy range

SINGAPORE - The haze situation here eased slightly overnight even as the air quality across the island remained in the unhealthy range.

At 7am on Oct 11, the 24-hour Pollutant Standards Index (PSI) readings stood at 119 in the north, 116 in the south, 140 in the east, 153 in the west and 153 in the central region.

This marks a slight improvement from a day before when the PSI value peaked at 183 in the central region at midnight before gradually dropping throughout the day.

Air quality is considered unhealthy when the PSI – a 24-hour rolling average of six key air pollutants – is in the range of 101 to 200.

Meanwhile, the PM2.5 reading remained in the elevated range across Singapore - 56 in the north, 64 in the south, 103 in the east, 108 in the west and 101 in the central region.

The hourly PM2.5 reading is used as a gauge for immediate air quality, with scores from 56 to 150 indicating elevated pollution levels while values of 151 to 250 represent high pollution levels.

In its daily advisory issued at 7pm on Oct 10, the National Environment Agency (NEA) said the 24-hour PSI is forecast to be in the “unhealthy to high unhealthy range”, staying out of the “very unhealthy” range of 201 to 300.

“Moderate to dense smoke haze from southern Sumatra was observed to drift towards Singapore. Smoke haze was also observed in many parts of Kalimantan,” it noted.

It added that the haze will continue to drift towards Singapore under prevailing east-south-easterly or southerlywinds.