PSI hits unhealthy levels, hazy conditions to continue into Tuesday, says NEA

The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
The Singapore skyline shrouded in haze as seen from the MBS Skypark on Oct 6, 2014, at 3pm. -- ST PHOTO: CAROLINE CHIA
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH 
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH 
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH 
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. -- ST PHOTO: JAMIE KOH 
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. Air quality has worsened over the last 12 hours with the three-hour Pollutant Standards Index (PSI) climbing to the unhealthy level of 118 as of
Haze covering the area around East Coast Park on Oct 6, 2014. Pictures taken from between 2pm - 3pm. Air quality has worsened over the last 12 hours with the three-hour Pollutant Standards Index (PSI) climbing to the unhealthy level of 118 as of 2pm on Monday.  -- ST PHOTO: JAMIE KOH
Sentosa Gateway shrouded in haze as seen from Mount Faber on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
Sentosa Gateway shrouded in haze as seen from Mount Faber on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
Buildings in the Central Business District shrouded in haze on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
Buildings in the Central Business District shrouded in haze on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
A cable car passes a barely visible Reflections at Keppel Bay condominium as seen from Mount Faber on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
A cable car passes a barely visible Reflections at Keppel Bay condominium as seen from Mount Faber on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
The silhouette of two visitors at Mount Faber seen against cable cars shrouded in haze on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
The silhouette of two visitors at Mount Faber seen against cable cars shrouded in haze on Oct 6, 2014. -- ST PHOTO: KEVIN LIM 
A hazy view of Redhill MRT Station at 3.30pm, Oct 6, 2014. The PSI at 4pm was at 132. -- ST PHOTO: LIM SIN THAI 
A hazy view of Redhill MRT Station at 3.30pm, Oct 6, 2014. The PSI at 4pm was at 132. -- ST PHOTO: LIM SIN THAI 
A barely visible Reflections at Keppel Bay condominium as seen from Mount Faber at 3.54pm on Oct 6, 2014. -- ST PHOTO: KEVIN LIM  
A barely visible Reflections at Keppel Bay condominium as seen from Mount Faber at 3.54pm on Oct 6, 2014. -- ST PHOTO: KEVIN LIM  
A barely visible PSA as seen at 5.42pm from Mount Faber on 6 October 2014. -- ST PHOTO: KEVIN LIM
A barely visible PSA as seen at 5.42pm from Mount Faber on 6 October 2014. -- ST PHOTO: KEVIN LIM

SINGAPORE - Air quality has worsened with the three-hour Pollutant Standards Index (PSI) climbing to the unhealthy level of 147 as of 6pm on Monday.

The latest PSI reading at 6am on Tuesday, Oct 7, is at 89.

It has been hazy in Singapore since the late morning on Monday, the National Environment Agency (NEA) said in an advisory.

Hotspots in Indonesia and wind direction

Source: National Environment Agency

When it is in the unhealthy range of above 100, people should cut down and avoid prolonged or strenuous outdoor physical activity, especially the elderly, pregnant women, children and people with chronic lung or heart diseases. At moderate levels of between 50 to 100, normal activities can still be carried out.

The NEA also said in its advisory that there are elevated levels of PM2.5 (small, toxic particles) in all parts of Singapore, with an especially high one-hour concentration in the southern part of Singapore. Southwesterly winds have blown in smoke haze from a nearby source in central Sumatra. The hazy conditions are expected to continue on Tuesday and overall air quality for the next 24 hours is expected to be in the high end of the moderate and unhealthy range.

The PSI measures soot, dust particles, sulphur dioxide, carbon monoxide, nitrogen dioxide and ground level ozone in the air.