SINGAPORE: The 24-hour Pollutant Standards Index (PSI) reading in the central region here reached a new peak this haze season early on Sept 29, as air quality across Singapore all breached the unhealthy band for the first time in two weeks.
The PSI reading – a 24-hour rolling average of six key air pollutants and to be used in planning for outdoor activities the next day – in central Singapore stood at 155 at 7am, surpassing the previous high of 154 on Sept 15.
The reading for the area further increased to 164 at 10am, a new high since the PSI first returned to the unhealthy range due to the haze on Sept 4.
Sept 15 was also the last time the readings in all five regions here surpassed the 101 threshold into the unhealthy range.
The PSI reading in the north was 101 at 7am, up from 98 an hour earlier, joining the south (129), east (128), west (139) and central (155) regions, which had entered the unhealthy range the night before.
As at 10am, the readings for the north (106), south (131), east (134) and west (148) also went up.
The one-hour PM2.5 readings, which are used as a gauge for immediate activities, also remained largely elevated nationwide, with a range of 57 to 95 at 10am, having all crossed into this band at 11pm on Sept 28.
However, these readings are generally on the downward trend, having peaked at a range of 85 to 165 at midnight.
Air quality is considered unhealthy when the 24-hour PSI is between 101 and 200, while an hourly PM2.5 reading between 56 and 150 indicates an elevated concentration of fine particles.
The 24-hour PSI re-entered the unhealthy range on the night of Sept 28, with the south (103) and central (104) areas crossing the threshold reading at 8pm.
At 9pm, the west also entered the unhealthy range with a reading of 101. This was joined by the east at midnight, with a reading of 103.
Some residents took to social media to comment on the hazy conditions.
In the CloudSpotting & SkySpotting Singapore Facebook group, user Jess Thia said she could “taste the bitterness" when she cracked open a window in a unit on a high floor at about 1am on Sept 29.
Meanwhile, user Prettyplushy Jamm, in a Sept 29 post sharing pictures of the smog, said she “didn’t even dare to open the windows”.
In another picture post sharing a hazy night view late on Sept 28, with a location tag of St Thomas Walk in River Valley, user Krittika Samaddar said: “Feeling terrified, never seen such haze during night time before.”
Jalan Besar GRC MP Shawn Loh said in a Facebook post on the morning of Sept 29 that Residents’ Network centres in Whampoa-Boon Keng, which are fully air-conditioned, are open for the public’s use from 10am to about 9pm daily.
Whampoa and Kallang Community Centres are also open daily, from 10am to about 9pm, to residents who need shelter from the haze, Loh said.
“The haze has gotten worse. Many residents, especially seniors and students who are studying for their exams, are understandably concerned. We will take action as a community,” he said.
In its daily haze advisory at about 6pm on Sept 28, the National Environment Agency (NEA) said air quality in Singapore for the next 24 hours was forecast to be in the high moderate to mid-unhealthy range.
It said that dry conditions are expected to persist over southern Sumatra and parts of Kalimantan.
While showers are forecast over Singapore on Sept 29, smoke haze may still affect the island with the prevailing winds expected to blow from the east or south-east, NEA said.
For periods when the air quality crosses into the unhealthy range, NEA has advised healthy people to reduce prolonged or strenuous outdoor activities, while vulnerable groups like the elderly, children and pregnant women, as well as people with chronic lung or heart disease, should minimise or avoid such activities altogether.
The PSI first returned to the unhealthy range due to the haze on Sept 4, the first time since October 2023. - The Straits Times/ANN
