Singapore's PSI level in 'moderate' range as number of Sumatra hotspots doubles

The haze on 24 September, 2015, in Singapore. (AP file photo)

SINGAPORE — The number of hotspots detected on Indonesia’s Sumatra island on Thursday (8 August) more than doubled to 116 from 56 the day before, said the National Environment Agency (NEA).

In a press release, the NEA said that most of the hotspots were detected in central and northern parts of Sumatra, and localised smoke plumes were observed from some of the hotspots within the island’s Riau province.

However, as of 6pm on Thursday, Singapore’s 24-hour pollutant standards index (PSI) reading remained in the “moderate” range of 63 to 68, with the one-hour PM2.5 concentration readings in Band I (Normal) at 21 to 34 µg/m3.

The prevailing winds are forecast to blow from the southeast or south on Friday, said the NEA, with fair and occasionally windy conditions expected over Singapore.

“The 24-hr PSI for the next 24 hours is forecast to be in the Moderate range, and the 1-hr PM2.5 concentration readings for the next 24 hours is expected to be in Band I (Normal),” it added. PM2.5 concentration readings measure the amount of particulate matter in the air.

The prevailing winds are forecast to continue blowing from the south-east or south over the next few days, with dry conditions expected to persist over Sumatra, said NEA.

“Singapore may experience slightly hazy conditions if the winds change to blow from the south-west or west,” said the agency, adding that it is monitoring the situation closely and will provide updates as necessary.

The NEA noted that, given the air quality forecast, members of the public can continue with normal activities over the next 24 hours. Those who are not feeling well, especially the elderly and children, and those with chronic heart or lung conditions, are advised to seek medical attention.

The main air pollutant during the haze season is PM2.5 and the public should use the one-hour PM2.5 concentration reading as an indicator for immediate activities like jogging, the agency added.

The NEA began issuing daily hazy advisories last Sunday, two days after it announced that the country may experience haze during the next few weeks to months.

According to the agency, two hotspots were detected in southern Sumatra last Sunday, with no visible smoke plumes or haze observed.

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