The haze descended on Singapore again yesterday as air quality dipped to its worst levels this year, driving some people indoors despite the public holiday. The authorities said the haze looks set to continue today.
The three-hour Pollutant Standards Index (PSI) hit an unhealthy 153 at 7pm.
At such levels, healthy people should reduce prolonged or strenuous outdoor physical exertion. Older folk, pregnant women and children should minimise such activity, while those who do not feel well or have chronic lung or heart conditions should avoid it.
The National Environment Agency (NEA) said that the pollution was due to smoke haze blown in from central Sumatra by prevailing south-westerly winds. There were 97 hot spots detected in Sumatra and 74 in Kalimantan. The haze is expected to continue today, with overall air quality remaining in the unhealthy range.
NEA said it has asked the Indonesian authorities for an update on the ground situation in Sumatra, and for them to take immediate action to extinguish the fires.
Yesterday, the levels of PM2.5, which are small, toxic particles, were elevated around the island, with the one-hour concentration rising to 131 micrograms per cubic metre in the southern areas at 6pm. A reading above 55mcg is considered unhealthy.
The highest three-hour PSI reading this year had previously been 129, recorded last month. Last year, the PSI reached an unprecedented 401 in June, a level considered hazardous.
Activities at mosques over the Hari Raya Haji holiday went on smoothly yesterday.
"Everything went well," said Imam Habib Hassan of Ba-Alwie Mosque in Bukit Timah. "Most of the prayers were held indoors, so there was no problem."
Some businesses with outdoor activities, however, saw a dip in customers.
Italian restaurant Casa Verde, which has outlets in the Singapore Botanic Gardens and Gardens by the Bay, had a 20 to 30 per cent drop in customers, while the cable-ski park Ski360 Degree in East Coast Park said sales dropped by around 10 per cent.
The pollution failed to deter many others, who were determined to stay outdoors and enjoy the public holiday. When The Straits Times visited Orchard Road yesterday afternoon, the outdoor walkways were packed.
And at the Marina Bay Sands Waterfront Promenade in the evening, around 400 people stopped by for band performances.
Housewife Cheren Wong, 47, was there with her sons, aged 15 and 17. "It's okay, as long as the PSI does not climb to over 200," she said. "If it continues to climb, it will definitely be a concern."
PSI readings of 201-300 are considered very unhealthy.
Added Mr R. Pillay, 52, an operations manager: "The air is stuffy but we have to get used to it because we are surrounded by countries with a lot of forests and this haze will not go away.
"Of course if it hits PSI 200, we will stay home."
In August, Singapore passed a transboundary haze law to punish firms that cause fires overseas which lead to haze here. And last month, Indonesia's lawmakers agreed to join the Asean Agreement on Transboundary Haze Pollution, which calls for countries to work together to fight the haze.