Singapore air quality deteriorates as three regions hit unhealthy PSI levels

Three of Singapore's five regions breached unhealthy air quality thresholds by mid-morning, signalling a deterioration in atmospheric conditions. The east, west and central zones registered PSI readings between 101 and 128 at 11am, placing them in the unhealthy category according to the National Environment Agency's air quality scale. The northern and eastern regions maintained better air quality metrics during the same period. The PSI scale rates air quality from 0 to 500, with readings above 100 considered unhealthy for the general population. Prolonged exposure at such levels is associated with adverse health effects, particularly for vulnerable groups including children, the elderly and individuals with respiratory conditions. Authorities have advised residents in affected areas to limit outdoor activities and use air purifiers where possible. The agency continues to monitor atmospheric conditions and has indicated that PSI levels may fluctuate throughout the day depending on wind patterns and regional pollution sources.