Haze watch: Air quality worsens in Singapore as PSI hits unhealthy range in all 5 regions

Residents in Singapore woke up to unhealthy air quality as 24-hour Pollutant Standards Index (PSI) entered the unhealthy range for all five regions on Tuesday (Sept 29).

Central and southern Singapore entered the range at 8pm on Monday, followed by the western and eastern regions at 9pm and midnight respectively.

The northern region crossed the threshold at 7am on Tuesday.

At 8am, PSI ranged from 103 to 158 — in the unhealthy range — with central Singapore recording the highest reading of 158.

This is followed by the western (143), eastern (130), southern (129) and northern (103) regions.

Meanwhile, one-hour PM2.5 is in the elevated band in the central (116), western (100), eastern (80) and northern (67) regions, with only southern (51) Singapore remaining in the normal band.

The concentration reading hit the high band for the first time in the ongoing haze season at midnight, recording a high of 165.

Readings of between 151 and 250 denote the high band.

In its daily haze situation update on Monday evening , the National Environment Agency (NEA) said the country's 24-hour PSI is forecast to be in the high-moderate to mid-unhealthy range.

The agency noted that moderate to dense smoke haze from fires in southern Sumatra and Kalimantan had drifted to Singapore.

With prevailing winds expected to blow from the east or southeast, there remains a risk of smoke haze continuing to affect Singapore, NEA explained.

Members of the public should note that the health impact of haze depends on an individual's health status, the PSI level, as well as the duration and intensity of outdoor activities.

Those planning outdoor activities in the next few hours are advised to check the one-hour PM2.5 readings, while the 24-hour PSI forecast should be used when planning activities for the following day.

周二（9 月 29 日），新加坡所有五个地区的 24 小时污染物标准指数 (PSI) 均进入不健康范围，居民们醒来后发现空气质量不佳。

新加坡中部和南部地区于周一晚上 8 点进入该范围，随后西部和东部地区分别于晚上 9 点和午夜进入该范围。

北部地区于周二早上7点突破了阈值。

上午 8 点，PSI 指数在 103 到 158 之间——处于不健康范围内——其中新加坡中部地区的读数最高，为 158。

其次是西部（143）、东部（130）、南部（129）和北部（103）地区。

与此同时，新加坡中部（116）、西部（100）、东部（80）和北部（67）地区的一小时 PM2.5 浓度处于较高水平，只有新加坡南部（51）的浓度仍处于正常水平。

午夜时分，浓度读数在持续的雾霾季节中首次达到高位，最高达到 165。

读数在 151 到 250 之间表示高频段。

国家环境局（NEA）在周一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）预计将处于高至中等至中度不健康范围。

该机构指出，来自苏门答腊南部和加里曼丹火灾的中等至浓重烟雾已经飘到了新加坡。

新加坡国家环境局解释说，由于预计盛行风向将来自东部或东南部，烟雾仍可能继续影响新加坡。

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。

计划在接下来的几个小时内进行户外活动的人们，建议查看一小时 PM2.5 读数；而计划第二天活动时，则应使用 24 小时 PSI 预报。