For many people, it was a usual weekend as they headed out for their outdoor activities, with the hazy skies and acrid smell clearing further yesterday.
The National Environment Agency (NEA) said in its haze advisory yesterday evening that there was a further improvement yesterday as the prevailing winds shifted to blow from the south.
Air quality is expected to improve further today, said the NEA. "Prevailing winds are forecast to strengthen and blow from the south or south-east," it said. "Overall, the PSI for the next 24 hours is forecast to be in the moderate range."
The agency added that the one-hour PM2.5 concentration over the next 24 hours is expected to stay in Band I (Normal).
Yesterday afternoon, the launch of the North West Life Saving Club, organised by the North West Community Development Council in partnership with the Singapore Life Saving Society, went on without a hitch at Choa Chua Kang Swimming Pool. About 700 people attended.
The Safra Singapore Bay Run & Army Half Marathon, held at Marina Bay in the morning, attracted about 42,000 people. Organisers had said that they would cancel the event if the three-hour Pollutant Standards Index (PSI) exceeded 200.
BETTER AND BETTER
Air quality is expected to improve further today. Prevailing winds are forecast to strengthen and blow from the south or south-east. Overall, the PSI for the next 24 hours is forecast to be in the moderate range.
THE NATIONAL ENVIRONMENT AGENCY, in its haze advisory yesterday evening.
Air quality is considered unhealthy when the 24-hour PSI is in the 101-200 range. The 24-hour PSI was in the moderate to unhealthy range yesterday morning, but dipped to the moderate range at 9am (70-100) and remained in that range. At 5pm, the reading went down further to 67-88. The one- hour PM2.5, which measures the one-hour concentration readings of the PM2.5 fine particles, was in the Band I (Normal) level at 5pm.
At Toa Payoh Stadium yesterday, there were at least 40 people running and playing soccer at around 6pm. People who headed out told The Straits Times they continued with their plans as the PSI readings had not reached unhealthy levels.
Mr Thomas Teng, 21, a student at NTUC LearningHub, was at City Hall MRT station at 7am to go for the 5km Fun Run of the Safra event. "It's still okay... (The PSI) is not at an unhealthy level yet," he said.
One person who went about his usual routine was Mr Yap Chee Heng, 63, who runs a plastic injection moulding firm. He continued with his regular 8km run last evening. "It is part of my lifestyle. If I don't run, I feel very lethargic or that something is missing," he said.
For people who are unsure if they should proceed with their activities, the NEA said that the one-hour PM2.5 concentration readings are a good indicator of the current air quality. "Use this for immediate activities like going for a jog," it said.
The PSI crept into the unhealthy range for the first time this year last Friday, as westerly winds brought smoke from forest fires in Sumatra, Indonesia, to Singapore.
• Additional reporting by Jeremy Koh