In pictures: Denser haze from Sumatra hits Singapore, PSI in very unhealthy range

The Straits TimesIn pictures: Denser haze from Sumatra hits Singapore, PSI in very unhealthy rangeThe Straits TimesHazy conditions worsened on Thursday as denser haze from Sumatra was blown in by the prevailing southerly winds. The 24-hour Pollutant Standards Index edged into the very unhealthy range, while the 3-hour reading hit a high of 262 at noon and 5pm.