Singapore air quality back to 'unhealthy' levels on Sunday

SINGAPORE — Singapore's air quality worsened on Sunday (Sept 22) with the Pollutants Standards Index (PSI) edging back to the "unhealthy" range across the country and one-hour PM2.5 readings rising to "elevated" levels.

As of 4pm, the PSI readings were:

• 105 in the north

• 113 in the east

• 120 in the south

• 106 in the west

• 106 in the central region

According to the National Environment Agency (NEA), PSI readings of 50 and below denote “good” air quality, “moderate” for 51-100 and “unhealthy” for 101-200.

The one-hour PM2.5 reading at 2pm ranged between 75-110 µg/m3, which is in the Elevated band. The reading was highest in the southern area, registering at 110 µg/m3.

PM2.5 is a measure of tiny particles less than 2.5 micrometres in diameter in the air. When the PM2.5 reading is in the elevated range, haze particles can affect the heart and lungs, especially in people who have chronic heart or lung conditions.

According to NEA, one-hour PM2.5 readings are a "good indicator of current air quality", and can be used for those deciding whether to go for immediate outdoor activities, such as a jog.

Singapore's skies had cleared in recent days, with PSI readings staying within the "moderate" band throughout the whole of Friday.

Organisers say they have a contingency plan if the haze worsens and have been stocking up on face masks to protect against pollution which spectators can buy at the circuit.

Indonesia, and its neighbours Malaysia and Singapore, have been worst affected by smog but it is starting to spread over a wider area in Southeast Asia.

Haze was detected Friday in central and southern parts of the Philippines, while thousands of schools have been forced to close in Malaysia and Indonesia amid mounting health concerns. CNA

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