Singapore, Oct 7 : The air quality in Singapore deteriorated into the unhealthy range on Saturday as the change in wind direction brought haze to the city state. The 24-hour Pollutant Standards Index (PSI) readings ranged between 61 and 107 this morning, with the highest reading recorded in the eastern part of the island, according to Singapore's National Environment Agency (NEA). A PSI reading of 101 to 200 is in the unhealthy range, Xinhua news agency quoted the NEA as saying. It suggests the public to reduce outdoor activities. Persistent hotspots producing dense smoke haze continued to be detected and observed in southern Sumatra. The smoke haze had been blown by the prevailing winds mainly towards the northwest and occasionally towards the north, the NEA said. It forecasts that persisting dry weather over southern and central Sumatra and southern Kalimantan over the next few days will elevate hotspot activity in these regions. As a result, hazy conditions are expected to be widespread. /IANS