Haze update Oct 7: 24-hour PSI forecast to be squarely in unhealthy range for the first time

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.

On Wednesday (Oct 7), 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.

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

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

At 6pm, PSI ranged from 105 in northern Singapore to 140 in the western region.

The next highest readings were recorded in central (135) and eastern (129) Singapore.

Meanwhile, one-hour PM2.5 is in the elevated band across all five regions, with the highest concentration reading of 136 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.

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

If PM2.5 concentration reading enters the high-band, healthy persons should avoid strenuous outdoor activity for the next hour, while vulnerable persons should avoid all outdoor activity for the next hour.

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。

周三（10 月 7 日），新加坡国家环境局表示，观测到来自苏门答腊南部的中等至浓重烟雾向新加坡飘移，同时在加里曼丹岛的热点地区也观测到中等至浓重的烟雾。

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。

“在盛行的东南风至南风的影响下，这些地区的烟雾可能会继续向新加坡飘去。

“预计新加坡24小时空气污染指数将处于不健康范围。”

下午 6 点，新加坡北部地区的 PSI 指数为 105，西部地区的 PSI 指数为 140。

新加坡中部（135）和东部（129）的读数次之。

与此同时，新加坡所有五个地区的 PM2.5 一小时浓度均处于较高水平，其中新加坡西部记录到的最高浓度读数为 136。

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——下午 4 点在新加坡西部曾短暂记录到这种情况。

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。

如果 PM2.5 浓度读数进入高值区间，健康人群应在接下来的一个小时内避免剧烈的户外活动，而易感人群应在接下来的一个小时内避免所有户外活动。