Haze watch: Unhealthy air quality across Singapore, PSI in west crosses 160

Residents in Singapore woke up to unhealthy air quality across the country on Thursday (Oct 8), with 24-hour Pollutant Standards Index (PSI) readings remaining in that range across all five regions.

At 9am, PSI ranged from 113 in northern Singapore to 161 in the western region.

The next highest recordings were recorded in central (145) and eastern (125) Singapore.

But one-hour PM2.5 concentration readings have improved overnight, returning to the normal band in southern (25), eastern, (42) and northern (37) Singapore.

The highest concentration reading of 61 was recorded in western Singapore.

Concentration readings between 56 to 150µg/m3 fall within the elevated band, while readings between 151 and 250 are in the high-band — briefly recorded in western Singapore at 4pm on Wednesday.

For the first time since the National Environment Agency (NEA) began providing daily haze situation updates on Sept 4, Singapore's 24-hour Pollutant Standards Index (PSI) is forecast to be squarely in the unhealthy range.

Over the last 33 editions, PSI forecast has either been in moderate range, or between moderate and unhealthy.

In its 34th daily haze situation update on Wednesday evening , NEA said that moderate to dense smoke plumes from southern Sumatra were observed to drift towards Singapore, while moderate to dense smoke haze was also observed from hotspots detected in Kalimantan.

In addition, the agency noted that dry conditions are expected to continue over the central and southern parts of Sumatra, as well as over many parts of Kalimantan.

Data from the Asean Specialised Meteorological Centre shows 94 hotspots in Kalimantan on Oct 7, while there were 210 hotspots in Sumatra.

"Under the prevailing south-easterly to southerly winds, smoke haze from these areas may continue to drift towards Singapore," said NEA.

"The 24-hr PSI for Singapore is forecast to be in the unhealthy range."

Members of the public should check the latest one-hour PM2.5 concentration readings before participating in outdoor activities.

周四（10 月 8 日），新加坡居民醒来发现全国各地的空气质量都不健康，五个地区的 24 小时污染物标准指数 (PSI) 读数均处于不健康范围内。

上午 9 点，新加坡北部地区的 PSI 指数为 113，西部地区的 PSI 指数为 161。

其次较高的记录出现在新加坡中部（145）和东部（125）。

但一夜之间，新加坡南部（25）、东部（42）和北部（37）的 PM2.5 浓度一小时读数有所改善，恢复到正常范围。

新加坡西部记录到的最高浓度读数为 61。

浓度读数在 56 至 150µg/m3 之间属于升高范围，而读数在 151 至 250 之间属于高范围——周三下午 4 点在新加坡西部曾短暂记录到这种情况。

自新加坡国家环境局 (NEA) 于 9 月 4 日开始提供每日雾霾情况更新以来，新加坡 24 小时污染物标准指数 (PSI) 预计将首次完全处于不健康范围内。

在过去的 33 届中，PSI 预测要么处于中等水平，要么介于中等和不健康之间。

新加坡国家环境局 (NEA) 在周三晚间发布的第 34 次每日雾霾情况更新中表示，观测到来自苏门答腊南部的中等至浓重烟柱正向新加坡飘移，同时在加里曼丹岛的热点地区也观测到中等至浓重的烟霾。

此外，该机构指出，苏门答腊中部和南部以及加里曼丹岛的大部分地区预计将持续干旱。

东盟专业气象中心的数据显示，10 月 7 日加里曼丹有 94 个热点，而苏门答腊有 210 个热点。

“在盛行的东南风到南风的影响下，这些地区的烟雾可能会继续向新加坡飘去，”国家环境局表示。

“预计新加坡24小时空气污染指数将处于不健康范围。”

公众在参加户外活动前，应查看最新的1小时PM2.5浓度读数。