SINGAPORE: Air quality in Singapore continued to worsen on Wednesday (Sep 18) night as the haze reached unhealthy levels across the island.
As of 11pm, the 24-hour Pollutant Standard Index (PSI) readings were:
- 122 in the north
- 137 in the east
- 145 in the south
- 127 in the west
- 124 in the central region
According to the National Environment Agency (NEA), PSI readings of 50 and below denote “good” air quality, “moderate” for 51-100 and “unhealthy” for 101-200.
The one-hour PM2.5 reading ranged from 102-150µg/m3 at 11pm, in the elevated band which ranges from 56-150µg/m3. The southern region had the highest levels of 150µg/m3.
PM2.5 is a measure of tiny particles less than 2.5 micrometres in diameter in the air. When the PM2.5 reading is in the elevated range, haze particles can affect the heart and lungs, especially in people who have chronic heart or lung conditions.
According to NEA, one-hour PM2.5 readings are a "good indicator of current air quality", and can be used for those deciding whether to go for immediate outdoor activities, such as a jog.
In an update on Wednesday evening, the environment agency said the 24-hour PSI readings are forecast to be in the high end of the moderate range and the low-end of the unhealthy range for the next 24 hours.
This could enter the mid-section of the unhealthy range if denser haze from Sumatra is blown in, it added.
The one-hour PM2.5 readings for this period are expected to range between normal and elevated.
"Given the air quality forecast for the next 24 hours, healthy persons should reduce prolonged or strenuous outdoor physical exertion," said NEA.
"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."
A total of 238 hotspots were detected in Sumatra on Wednesday, up from 109 on Tuesday. However, the lower number was due to a "partial satellite pass", which occurs when a satellite's field of view covers only part of a region of interest as the satellite orbits the earth.
There is still moderate to dense smoke haze in Indonesia's central and southern provinces of Riau, Jambi, South Sumatra and Lampung, said NEA.
The Singapore Government said it has put in place "robust action plans" to minimise and manage the impact of haze on the public.
These include making sure that there are enough N95 masks, and for hospitals to be ready for any increase in haze-related cases.