"Based on the latest satellite images, there were no
significant hotspots or smoke haze detected in the nearby region,"
said a spokesman for the National Environment Agency (NEA).
"The haziness was due to the accumulation of
particulate matter under light wind conditions," the spokesman
added.
The 24-hour Pollutant Standards Index (PSI) reached a
high of 95 in southern Singapore at 8am yesterday.
A PSI reading above 100 indicates unhealthy air
quality, while a reading of between 51 and 100 is considered
moderate.
Under moderate conditions, normal activities can be
carried out.
The 24-hour PSI across Singapore hovered in this range
for the rest of the day, although readings in southern Singapore
leaned toward the higher end.
Experts told The Straits Times there were a negligible
number of hotspots in Riau, Sumatra or Kalimantan - areas in
Indonesia where fires are started that are usually the cause of
smoke haze.
"This makes Indonesia unlikely to be the source of the
bad air," noted volunteer group PM.Haze (People's Movement to Stop
Haze), which monitors haze in Singapore.
"Another significant source of our poor air is exhaust
from traffic," said PM.Haze executive director Zhang Wen.
Usually, domestic pollution is blown away by the wind,
she said. "But as it was not windy yesterday, the pollutants could
not disperse, making it look hazy."
TNP
