Singapore air quality deteriorates to unhealthy levels across island

Singapore's air quality is expected to deteriorate significantly, with the National Environment Agency issuing an update on Monday evening warning of poor atmospheric conditions. The 24-hour Pollutant Standards Index, or PSI, forecast indicates readings will rise into the high moderate to mid-unhealthy range, impacting residents across most areas of the city-state.

The PSI is Singapore's primary air quality indicator, measuring concentrations of five major pollutants including nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide, and particulate matter. Readings in the high moderate range typically prompt health advisories for vulnerable populations, while the mid-unhealthy threshold marks a further deterioration requiring broader precautions.

Residents experiencing respiratory conditions, the elderly, and young children are typically advised to limit outdoor activities when air quality reaches unhealthy levels. The agency's forecast suggests the poor air conditions are expected to persist throughout the 24-hour period, though specific triggers for the deterioration were not immediately detailed in the update.

Singapore regularly experiences air quality challenges, particularly during transboundary haze episodes linked to regional burning in neighbouring countries. The island's location in Southeast Asia makes it susceptible to seasonal variations in air quality, with authorities maintaining continuous monitoring systems across multiple stations.