Haze update Sept 29: Air quality improves slightly; Singapore's 24-hour PSI forecast to be in high-moderate to low-unhealthy range
Singapore's air quality gradually improved throughout Tuesday (Sept 29), with one-hour PM2.5 concentration readings easing into normal to elevated bands, while the 24-hour Pollutant Standards Index (PSI) reading fell.At 6pm, the 24-hour PSI readings for all five regions remained in the unhealthy range, with central Singapore recording the highest reading of 153.Meanwhile, one-hour PM2.5 ranged from 44 to 76 — in the normal to elevated bands — with only eastern (76) and western (56) Singapore recording concentration readings in the higher of two bands.The National Environment Agency (NEA) said in its daily haze situation update on Tuesday evening that it expects the country's 24-hour PSI forecast to be in the high-moderate to mid-unhealthy range. Moderate to dense smoke haze from fires in Kalimantan have continued to drift towards Singapore, while haze was also observed from fires detected in southern Sumatra, NEA explained.