The haze worsened yesterday as Singapore was again shrouded in smoke after some respite over the past few days. Air quality today could deteriorate and hit unhealthy levels as well.
The National Environment Agency (NEA) said that haze conditions became worse yesterday afternoon due to haze from Sumatra blown in by prevailing south-southeasterly winds.
"There has been an increase in the extent of moderate to dense haze over southern and central Sumatra," NEA said in a 6pm statement.
The 24-hour Pollutant Standards Index (PSI) was mostly in the high end of the moderate range (51 to 100) earlier in the day, but crept into the low end of the unhealthy range (101 to 200) at 5pm in some parts of Singapore. At 7pm, it stood at between 85 and 113.
On Monday, the 24-hour PSI kept mostly to the high-end of the moderate range.
Yesterday's three-hour PSI, which is averaged over a shorter period and not tied to health advisories, rose steadily in the morning and crossed the 100 level at 1pm. It hit 161 at 5pm before falling to 132 at 7pm.
NEA said the haze is still expected today. The 24-hour PSI for the next 24 hours is expected to be in the low to mid sections of the unhealthy range. If denser haze from Sumatra is blown in, the PSI could enter the high end of the unhealthy range.
Based on the forecast for air quality, healthy people should reduce prolonged or strenuous outdoor physical exertion, said NEA. The elderly, pregnant women and children should minimise such activities, while those with chronic lung or heart disease should avoid them.
Those who do not feel well, especially the elderly and children, and people with chronic heart or lung conditions, should seek medical attention.
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