[UPDATED on Friday, 13 February at 4:40pm: Adding comments from NEA]
A spokesperson for Singapore’s National Environment Agency (NEA) on Friday said that the air quality in Singapore continues to be “moderate”, in response to queries from Yahoo Singapore.
She also added that NEA has contacted their counterparts in Malaysia to check if any changes to air quality had been observed in Johor.
“NEA will continue to monitor the air quality readings and notify the public if there are any changes to the PSI,” she said.
This comes after the pollutant concentrations index, better known as the PM2.5 reading, spiked in the East area of Singapore overnight on Friday, following complaints from residents in the area of a "burning smell" on Thursday evening.
The one-hour PM2.5 reading in the East area was 97 at 1am, and dropped to 76 before spiking to 155 at 3am. It later fell to 24 at 4am, but at 8am, it shot back up to 51 from 17 at 7am.
PM2.5 readings measure the amount of particulate matter smaller than or equivalent to 2.5 micrometers in size, which are considered to pose the greatest amount of health risk because they can lodge deeply into human lungs.
These levels were all below 22 around the rest of the island overnight, with only the West area showing a reading of 28 at 8am.
On Wednesday evening, residents in Siglap, Pasir Ris, East Coast Road and Bedok reported detecting a "strong burning smell". On Friday morning, commuters travelling from the East noticed hazier-than-usual conditions.
The 24-hour Pollutant Standards Index (PSI) in the East was also consistently higher than in the rest of the country, staying well above 70 through the night, and stood at 78 at 8am. Around the North, West, South and central regions, PSI levels hovered mostly below 60.