The air quality in the eastern part of Singapore briefly entered the unhealthy range on Saturday, January 24, with fine particulate matter levels rising in the late afternoon, according to the National Environment Agency (NEA).
The PM2.5 concentrations in the area recorded a reading of 162 at about 4.45 pm, indicating elevated levels of fine inhalable particles measuring up to 2.5 micrometres in diameter. In a Facebook post, NEA described the PM2.5 levels as "slightly elevated".
Some residents had reported detecting a faint burning smell. NEA said this was likely caused by a hotspot and smoke plume detected in Johor, which is located close to Singapore. With prevailing winds blowing from the north and north-east, the haze was believed to have drifted across the border and temporarily affected local air quality.
By 8 pm, air quality conditions in the eastern region had improved. NEA's website showed PM2.5 levels had returned to the normal range with a reading of 27, while the Pollutant Standards Index (PSI) stood at 58, which falls within the moderate category.
Air quality is considered normal when PM2.5 levels are between zero and 55, while readings from 151 to 250 indicate high concentrations of fine particles. Members of the public can monitor the latest air quality updates through the myENV mobile application.
