SINGAPORE - Singapore's air is expected to remain unhealthy or close to unhealthy for the rest of the day, said the National Environment Agency (NEA) on Monday.
It said in an update on the haze situation that the 24-hour Pollutant Standards Index is expected to "fluctuate between the high-end of the moderate range and the low-end of the unhealthy range for the rest of the day".
Air quality is moderate when the PSI is between 51 and 100, and unhealthy when it crosses 100.
The NEA added that levels of PM2.5, which are smaller, toxic particles, were also higher than usual between 10pm on Sunday night and 7am on Monday.
This was likely due to hotspots or fires in South Sumatra, Indonesia in the past three to four days.
"Given the continued dry weather in southern Sumatra, we can expect the hotspots to persist," it said.
The agency said that given the air quality forecast for the next 24 hours, healthy people should reduce prolonged or strenuous outdoor physical exertion. The elderly, pregnant women and children should minimise such activity while those with chronic lung or heart disease should avoid it all together.
The 24-hour PSI as at 10am on Monday ranged from 78 to 106 across the island and was worst in the west, while the 3-hour PSI, which averages readings in the past three hours, was 82.