Singapore Air Quality Dips Overnight After Brief 'Moderate' Respite - Tempo.co English
TEMPO.CO, Jakarta - After brief improvements on October 4, the air quality in Singapore's central and west regions crossed into the unhealthy range overnight, as reported by The Straits Times and CNA.
On Monday, the 24-hour Pollutant Standards Index (PSI) reading hit 110 in the central region and 102 in the west early in the morning, steadily going up until it hit 120 in the central region and 114 in the west by 3:00 p.m. local time.
Meanwhile, the Air Quality Reading (AQI) reading based on the global air monitoring platform IQAir showed Singapore air quality hitting 168 at 04:00 p.m., with PM2.5 pollution reaching 79.4 µg/m³.
The air quality in other parts of the island nation, meanwhile, remained in the moderate range.
The PM2.5 reading stood at 93 in Singapore's central region, and 81 in the west, which indicates an elevated concentration of fine particles.
Singapore's National Environment Agency (NEA) had anticipated the worsening air quality in its Monday forecast, which it said would be in the "high moderate to low unhealthy" range, according to The Straits Times.
NEA said the haze situation is expected to remain escalated as dry conditions persist on Monday. The agency said scattered hotspots were detected in southern parts of Sumatra, sending dense smoke plumes northward towards parts of Malaysia and Singapore. Meanwhile, some haze was observed from fires in Kalimantan, with isolated hotspots observed in parts of Java and Sulawesi.
Singapore measures daily air quality with the 24-hour PSI, which forms the basis of NEA's health advisories for the day. The agency advises reduced outdoor activities once the reading crosses the unhealthy range of 101 to 200.
Meanwhile, PSI readings 201-300 is deemed "very unhealthy," and anything above that is considered "hazardous," citing CNA. Air quality is good with values of 0-50.
Singapore's 24-hour PSI is calculated using six air pollutants: PM2.5, PM10, ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide.
Haze and fire smoke carry PM2.5, fine particulate matter that is far smaller than a strand of hair and can travel deep into the lungs when inhaled.
Singapore also measures hourly readings to gauge current concentrations of PM2.5, which is considered elevated if they fall between 56 and 150. The one-hour PM2.5 reading is useful to decide whether outdoor activities are immediately advisable.
Singapore's PSI crossed into the unhealthy range a month ago, as fires ravage Indonesia's forests, particularly in Kalimantan and Sumatra, sending smoke plumes into the island nation. In the days that followed, readings in the central, eastern and western parts of Singapore crossed into the unhealthy range occasionally, according to The Straits Time.
The highest reading so far this year was in central Singapore, reaching 167 on September 29.
Authorities have also warned of haze risks earlier this year, as El Nino and the Indian Ocean Dipole brought warmer and drier conditions in the region for longer periods compared to non-El Nino years. This year marks the first time since October 2023 that air quality levels cross the unhealthy levels in Singapore due to haze.
