Haze in S’pore: PM2.5 reading in the west returns to normal zone after entering elevated range

SINGAPORE – Air quality worsened in the west on the morning of Oct 29, with the one-hour PM2.5 readings at 57, in the elevated range.

It is the first time since the afternoon of Oct 27 that the current air quality in any of the five regions here entered the elevated range.

At 11am, the one-hour PM2.5 readings for the remaining regions stood between 25 and 46.

PM2.5 readings are gauged hourly and reflect the current air quality. Scores from zero to 55 represent normal values, and those between 56 and 150 indicate an elevated concentration of fine particles.

The 24-hour PSI readings remained in the good to moderate band, ranging from 69 to 78, as at 11am on Oct 29.

Air quality is considered good to moderate when the PSI – a 24-hour rolling average of six key air pollutants – is in the range of zero to 100, and unhealthy when it is in the range of 101 to 200.

When air quality breaches the “unhealthy” threshold, people, especially the elderly, children and those with health issues, should scale down outdoor activities.