PSI at unhealthy levels — how you can protect yourself from the haze

With Indonesia's Sumatra and Kalimantan battling wildfires over the past weeks, Singapore is now experiencing episodes of haze.According to the National Environment Agency's haze microsite, the 24-hour Pollutant Standards Index (PSI) levels rose to 103 in Singapore's central region on Friday (Sept 4).A PSI of 101-200 indicates unhealthy air quality levels.As Singapore experiences a drop in air quality, some people...