Hazy conditions are expected to persist on Saturday (Aug 27), although there was some improvement in air quality, the National Environment Agency (NEA) said.

The improvement in the haze situation on Saturday morning was due to a slight shift in the direction of prevailing winds overnight from westerly to west-southwesterly, the agency said.

As of noon, the 24-hour PSI reading was 83-137, in the Moderate to Unhealthy range, and the 1-hour PM2.5 level was 36-121 µg/m3, in Band I to II (Normal to Elevated).

As the latest satellite image shows hotspots with haze still persisting in central Sumatra, hazy conditions are expected on Saturday. However, air quality is likely to improve in the evening, when prevailing winds are forecast to blow from the southwest, NEA said.

Overall, the PSI reading for the next 12 hours is forecast to be in the high end of the Moderate range or low end of the Unhealthy range. The 1-hour PM2.5 concentration over the next 12 hours is expected to fluctuate between Band I (Normal) and Band II (Elevated).

The health impact of haze is dependent on one’s health status, the PSI level, and the length and intensity of outdoor activity, NEA said, adding that reducing outdoor activities and physical exertion can help limit the ill effects from haze exposure.

"Given the air quality forecast for the next 12 hours, healthy people should reduce prolonged or strenuous outdoor physical exertion. The elderly, pregnant women and children should minimise prolonged or strenuous outdoor physical exertion, while those with chronic lung or heart disease should avoid prolonged or strenuous outdoor physical exertion.”

People who are not feeling well, especially the elderly and children, and those with chronic heart or lung conditions, should seek medical attention, NEA added.