Air quality in southern Singapore back to moderate range

SINGAPORE – Air quality in the southern region of Singapore improved on the evening of Oct 6, with the latest 24-hour Pollutant Standards Index reading there dropping from the unhealthy band to the moderate band.

The reading there at 8pm was 99, a dip from 101 an hour before.

The PSI readings for the other parts of the island remained in the unhealthy range, falling between 104 and 131.

Air quality is considered unhealthy when the 24-hour PSI – a rolling average of six key air pollutants and used in planning for outdoor activities the next day – is in the range of 101 to 200.

The hourly PM2.5 readings for the northern and southern areas also dropped to the normal band as at 8pm, at 50 and 53 respectively.

A PM2.5 reading that falls between 56 and 150 indicates an elevated concentration of fine particles in the air.

In its daily haze advisory on Oct 6, the National Environment Agency said that with the prevailing winds expected to blow from the south-east or east-south-east, the 24-hour PSI is forecast to be in the “high moderate to mid unhealthy” range.

Dry conditions are expected to persist over Kalimantan and southern Sumatra in neighbouring Indonesia, where moderate to dense smoke plumes were observed to be drifting towards Singapore.