Channel NewsAsia reported that air quality across Singapore had improved by Thursday afternoon, while the National Environment Agency (NEA) warned that fires and dry conditions could keep haze risk active.
At 4 a.m. ET Thursday (4 p.m. Singapore time), Channel NewsAsia put the five regions’ 24-hour PSI readings at 71–97 and their hourly PM2.5 levels at 25–38 micrograms per cubic meter.
At 8 p.m. ET Wednesday (8 a.m. Singapore time Thursday), the west was the only region still recording an unhealthy 24-hour PSI. It entered the moderate range at 3 a.m. ET Thursday (3 p.m. Singapore time), Channel NewsAsia reported.
Singapore’s Ministry of Health (MOH) classifies PSI readings of 51 to 100 as moderate and one-hour PM2.5 concentrations of zero to 55 micrograms per cubic meter as normal. The PSI reflects air quality over a longer period, so it may remain moderate while the latest hourly reading is normal. MOH advises people to use the hourly measure when making immediate outdoor plans.
NEA had forecast a 24-hour PSI of 101 to 160 for Oct. 22, within the unhealthy category of 101 to 200. At 7 a.m. ET Oct. 21 (7 p.m. Singapore time), the agency recorded PSI readings from 80 to 123 and hourly PM2.5 from 34 to 92 micrograms per cubic meter.
Singapore’s Ministry of Manpower said Oct. 20 that it had issued guidance for employers on adjusting outdoor work based on hourly PM2.5 readings during haze. EconoTimes previously reported on the employer guidance.
In its Oct. 22 regional update, NEA reported scattered to widespread fire hotspots in Kalimantan and southern Sumatra and said dry conditions could sustain the risk of haze crossing borders. An Oct. 21 advisory said smoke from Kalimantan may continue reaching Singapore Friday, Oct. 23, while a wind shift could carry smoke from Sumatra toward the island Saturday, Oct. 24.
