Singapore: Witnessing History…321 PSI

singapore_smoke_worse

top shots taken on Monday (6/17), bottom shots taken (6/19). Clark Quay

Excerpt from Straits Times:

SINGAPORE’S air is now “hazardous” as the Pollutant Standards Index soared to 321 at 10pm, the worst reading in its history.

Air becomes “hazardous” when the index passes 300. The previous worst reading was 226, in 1997.

From Wikipedia:

PSI Descriptor General Health Effects
0 – 50 Good None
51 – 100 Moderate Few or none for the general population
101 – 200 Unhealthy Mild aggravation of symptoms among susceptible persons i.e. those with underlying conditions such as chronic heart or lung ailments; transient symptoms of irritation e.g. eye irritation, sneezing or coughing in some of the healthy population.
201 – 300 Very Unhealthy Moderate aggravation of symptoms and decreased tolerance in persons with heart or lung disease; more widespread symptoms of transient irritation in the healthy population.
301 – 400 Hazardous Early onset of certain diseases in addition to significant aggravation of symptoms in susceptible persons; and decreased exercise tolerance in healthy persons.
Above 400 Very Hazardous PSI levels above 400 may be life-threatening to ill and elderly persons. Healthy people may experience adverse symptoms that affect normal activity.