Haze pushes air quality in central Singapore back into unhealthy range as PSI hits 102雾霾导致新加坡中部空气质量再次跌至不健康水平，PSI值高达102。
The Republic's air quality returned to the unhealthy range at 9pm on Thursday (Sept 17) as 24-hour Pollutant Standards Index (PSI) hit 102 in central Singapore.Elsewhere, western Singapore recorded the next highest PSI reading of 93.Data from the National Environment Agency (NEA) shows one-hour PM2.5 concentration readings entering the elevated band at 11am, before climbing gradually to 93 by 9pm....
The Republic's air quality returned to the unhealthy range at 9pm on Thursday (Sept 17) as 24-hour Pollutant Standards Index (PSI) hit 102 in central Singapore.
Elsewhere, western Singapore recorded the next highest PSI reading of 93.
Data from the National Environment Agency (NEA) shows one-hour PM2.5 concentration readings entering the elevated band at 11am, before climbing gradually to 93 by 9pm. Readings between 56 to 150 denote the elevated band.
Meanwhile, one-hour PM2.5 reading was between 40 and 64 in the four remaining regions, with western Singapore recording the next highest reading of 64, also in the elevated band.
High moderate to low-unhealthy forecast
In its daily haze situation update on Thursday evening, NEA had said the country's 24-hour PSI forecast is expected to be in the high moderate to low unhealthy range.
Explaining this, the agency noted that smoke haze was observed to have drifted from southern and central Sumatra towards Singapore, while smoke plumes were also detected over southwestern Kalimantan.
"With the prevailing winds forecast to blow from the southeast to southwest, there is a risk of smoke haze affecting Singapore," NEA said
What the PM2.5 readings mean for outdoor activities
PM2.5 is the current air quality that matters — when planning to conduct or participate in outdoor activities immediately.
When PM2.5 readings are in the elevated band, members of the public should reduce strenuous outdoor activity for the next few hours.
Vulnerable persons such as the elderly, pregnant women, children, and persons with chronic lung or heart disease should avoid strenuous outdoor activity.
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.
For the general population, symptoms that may arise from short-term exposure include throat or eye irritation.
These symptoms are typically temporary and should subside once a person leaves the affected environment.
周四（9 月 17 日）晚上 9 点，新加坡中部 24 小时污染物标准指数 (PSI) 达到 102，共和国空气质量再次回到不健康范围。
新加坡西部地区则录得第二高的PSI读数，为93。
国家环境局（NEA）的数据显示，PM2.5一小时浓度读数在上午11点进入高浓度区间，随后逐渐攀升，到晚上9点达到93。读数在56到150之间表示处于高浓度区间。
与此同时，其余四个地区的 PM2.5 一小时读数在 40 至 64 之间，其中新加坡西部地区的读数位居第二高，为 64，也处于较高水平。
高、中、低至不健康预测
国家环境局在周四晚间发布的每日雾霾情况更新中表示，该国24小时空气污染指数（PSI）预计将处于高、中、低、不健康范围内。
该机构解释说，观察到烟雾从苏门答腊南部和中部向新加坡飘移，同时在加里曼丹西南部也检测到了烟雾。
“由于预计盛行风向将从东南风吹向西南风，新加坡有可能受到烟霾影响，”国家环境局表示。
PM2.5读数对户外活动意味着什么
PM2.5 是当前最重要的空气质量指标——当您计划立即进行或参与户外活动时。
当 PM2.5 读数处于较高水平时，公众应在接下来的几个小时内减少剧烈的户外活动。
老年人、孕妇、儿童以及患有慢性肺病或心脏病等弱势群体应避免剧烈的户外活动。
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。
对于普通人群而言，短期接触可能出现的症状包括喉咙或眼睛刺激。
这些症状通常是暂时的，一旦离开受影响的环境，症状就会消退。