Haze update Sept 18: Singapore air quality moderate; 24-hour PSI forecast in high-moderate to low-unhealthy range9月18日雾霾最新消息：新加坡空气质量为中等；24小时空气污染指数（PSI）预测为中高至不健康范围。
Singapore's air quality remained in the moderate range on Friday (Sept 18).The 24-hour Pollutant Standards Index (PSI) turned unhealthy in central Singapore at 9pm on Thursday night, remaining in that range for about four hours. As at 5pm on Friday, the 24-hour PSI ranged from 64 to 86 — in the moderate range — with central Singapore recording the highest...
Singapore's air quality remained in the moderate range on Friday (Sept 18) .
The 24-hour Pollutant Standards Index (PSI) turned unhealthy in central Singapore at 9pm on Thursday night , remaining in that range for about four hours.
As at 5pm on Friday, the 24-hour PSI ranged from 64 to 86 — in the moderate range — with central Singapore recording the highest PSI of 86. This was followed by western Singapore, with a PSI reading of 79.
Meanwhile, one-hour PM2.5 concentration readings ranged between 31 to 61, in the normal to elevated bands.
Central Singapore was the only region in the elevated band, while the other four regions remained in the normal band as at 5pm.
The one-hour PM2.5 reading reflects current air quality and should be used when deciding whether to carry out outdoor activities in the next few hours.
In its daily haze update on Friday evening, the National Environment Agency (NEA) said the country's 24-hour PSI forecast is expected to remain in the high moderate to low unhealthy range.
This, it said, is due to smoke plumes from fires in Kalimantan drifting towards Singapore. Some smoke plumes were also observed over southern Sumatra, the agency added.
Given that prevailing winds are expected to blow from the east-southeast or southeast, NEA said the risk of smoke haze affecting Singapore remains.
Members of the public should note that the health impact of haze is dependent on one's health status, the PSI level, and the length and intensity of outdoor activity.
新加坡周五（9月18日）的空气质量仍处于中等水平。
周四晚上9点，新加坡中部地区的24小时污染物标准指数（PSI）达到不健康水平，并持续了约4个小时。
截至周五下午5点，24小时空气污染指数（PSI）在64至86之间，属于中等范围，其中新加坡中部地区的PSI最高，为86。其次是新加坡西部地区，PSI读数为79。
与此同时，一小时 PM2.5 浓度读数在 31 至 61 之间，处于正常至偏高的范围内。
截至下午 5 点，新加坡中部地区是唯一处于较高警戒级别的地区，而其他四个地区仍处于正常警戒级别。
一小时 PM2.5 读数反映了当前的空气质量，应以此来决定在接下来的几个小时内是否进行户外活动。
国家环境局（NEA）在周五晚间的每日雾霾更新报告中表示，该国24小时空气污染指数（PSI）预计将保持在较高、中等至较低、不健康的范围内。
报告称，这是由于加里曼丹岛火灾产生的烟雾飘向新加坡所致。该机构还补充说，苏门答腊南部也观测到了一些烟雾。
鉴于预计盛行风向将来自东南偏东或东南方向，新加坡国家环境局表示，烟雾影响新加坡的风险依然存在。
公众应注意，雾霾对健康的影响取决于个人的健康状况、PSI 值以及户外活动的持续时间和强度。