Singapore PSI climbs into unhealthy range in all five regions by early Saturday

Air quality in Singapore got worse overnight. The 24-hour Pollutant Standards Index (PSI) climbed into the unhealthy band in every one of the five regions by early Saturday. At 6am, readings ran from 112 to 139, and the west had the highest figure. Across the island, hourly PM2.5 readings were raised too, with the east at 72 and the west at 115.

What the National Environment Agency expects

The National Environment Agency (NEA) forecast a PSI of 90 to 140 for Saturday, which covers both the moderate and unhealthy categories. Showers are forecast for Singapore and nearby areas, but smoke haze could still be carried over from Sumatra by the prevailing winds. From Sunday, winds are expected to blow from the southwest or west, which could cut the amount of smoke haze heading towards Singapore. Rain showers may further relieve conditions.

Conditions had deteriorated progressively by Friday, with the western and central regions the earliest to hit the unhealthy range. NEA said smoke haze from Sumatra had been seen drifting towards Singapore, and haze was also detected over Kalimantan. Dry conditions over Singapore had also played a part.

Advice for outdoor activities

People were urged by NEA to consult the 24-hour PSI forecast while planning outdoor activities, and to look at the most recent 1-hour PM2.5 readings before going outside straight away. When hourly PM2.5 is in the elevated band, healthy people should cut back on strenuous outdoor activity for the next hour. During that hour, strenuous outdoor activity should be avoided by children, the elderly, pregnant women and anyone with chronic heart or lung conditions.

NEA said that on Saturday, elderly people, pregnant women and children should minimise prolonged or strenuous outdoor exertion, whereas healthy people should cut back on it. Anyone suffering from chronic heart or lung disease is advised to steer clear of it.

Action on companies

Scattered hotspots across southern Sumatra and Kalimantan were found in a regional assessment published on Friday, which also reported moderate to dense transboundary smoke haze affecting Singapore and some neighbouring areas. The first use of the Transboundary Haze Pollution Act since it took effect came on Friday, when NEA served notices on 10 companies based in Singapore. Requests went out to the firms, which operate in palm oil or forestry, for details of their corporate links, land concessions in Indonesia and the steps they took to prevent and fight fires. NEA is also seeking more information from 10 Indonesian companies that received notices over the past week.

Plans for a specialist panel made up of legal, audit and investigative firms, to look into companies possibly tied to the haze, were announced separately by the Ministry of Law. Corporate structures, supply chains and business relationships spanning jurisdictions will be examined by it, in order to help determine if companies played a part in causing or condoning the fires.