Haze update Oct 17: Weekend begins with better air quality as PSI drops to unhealthy range, PM2.5 elevated

The weekend (Oct 17) started with improved air quality as all five regions across Singapore returned to the unhealthy range overnight.

At 9am, 24-hour Pollutant Standards Index (PSI) ranged from 142 in northern Singapore to 187 in the central region.

Meanwhile, hourly PM2.5 is in the elevated band at all five regions.

In its daily haze situation update on Friday night , the National Environment Agency (NEA) said the 24-hour PSI is forecast to be between 150 to 230.

This is in the unhealthy to very unhealthy range, even as some showers are expected over Singapore and surrounding region, including parts of Kalimantan.

But there could be cause for limited optimism on Oct 17, with winds forecast to shift to blow from the southeast or south-southeast.

"The transport of smoke haze from Kalimantan to Singapore may be reduced. However, some smoke haze from Sumatra may drift towards Singapore," the agency stated.

On Sunday and Monday, showers are forecast over Singapore and parts of Kalimantan, while winds are expected to gradually weaken and blow from the southeast or south.

"This could further decrease the transport of smoke haze from Kalimantan to Singapore, although some smoke haze from Sumatra may drift towards Singapore," NEA said.

Situation could improve by early November: Grace Fu

During a whole-of-government press conference on the haze situation on Friday afternoon, Minister for Sustainability and the Environment Grace Fu urged Singaporeans to be prepared for the haze to "persist for some time".

"The situation is fluid. Depending on the weather, we can expect air quality to fluctuate, including the possibility of reaching hazardous level (PSI >300)," the minister said.

But she also pointed out that the situation could improve by end-October or early-November as winds become lighter and more variable during the inter-monsoon period.

And by around early-December, with the onset of the northeast monsoon, any haze from Sumatra and Kalimantan will blow in the direction away from Singapore, she added.

While members of the public can use the PSI forecast to plan for their activities, they should track the latest hourly PM2.5 concentration readings before taking part in outdoor activities.

Although a low 24-hour PSI may generally indicate a good condition, a high one-hour PM2.5 reading could indicate that conditions have recently worsened, even though the longer-term average has not risen yet.

When PM2.5 concentration readings are in 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.

Those who are vulnerable may also wear to a N95 mask to reduce exposure.

周末（10 月 17 日）伊始，新加坡五个地区的空气质量有所改善，一夜之间所有地区的空气质量都恢复到了不健康水平。

上午 9 点，新加坡 24 小时污染物标准指数 (PSI) 从北部的 142 到中部地区的 187 不等。

与此同时，五个地区的每小时 PM2.5 浓度均处于较高水平。

国家环境局（NEA）在周五晚间发布的每日雾霾情况更新中表示，预计24小时PSI指数将在150至230之间。

尽管预计新加坡及周边地区（包括加里曼丹部分地区）会有阵雨，但目前的空气质量仍处于不健康到非常不健康的范围内。

但10月17日可能会出现一些令人稍感乐观的情况，预计风向将转为东南风或东南偏南风。

该机构表示：“从加里曼丹岛向新加坡输送的烟霾可能会减少。但是，来自苏门答腊岛的部分烟霾可能会飘向新加坡。”

预计周日和周一新加坡和加里曼丹部分地区将有阵雨，风力预计逐渐减弱，并由东南风或南风吹来。

“这可能会进一步减少加里曼丹岛向新加坡输送的烟霾，尽管苏门答腊岛的一些烟霾可能会飘向新加坡，”新加坡国家环境局表示。

傅慧玲：情况可能在11月初有所好转。

周五下午，在政府就雾霾情况举行的新闻发布会上，永续发展及环境部长傅海燕敦促新加坡人做好准备，雾霾可能会“持续一段时间”。

“情况瞬息万变。根据天气情况，空气质量可能会波动，甚至可能达到危险水平（PSI > 300）。”部长说。

但她也指出，到 10 月底或 11 月初，随着季风间歇期风力减弱且变化无常，情况可能会有所改善。

她补充说，到 12 月初左右，随着东北季风的到来，来自苏门答腊和加里曼丹的任何雾霾都会向远离新加坡的方向吹去。

虽然公众可以利用 PSI 预报来计划他们的活动，但他们在参加户外活动之前应该关注最新的每小时 PM2.5 浓度读数。

虽然 24 小时 PSI 值较低通常可能表明空气质量良好，但 1 小时 PM2.5 读数较高可能表明空气质量最近有所恶化，即使长期平均值尚未上升。

当 PM2.5 浓度读数处于较高水平时，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。

易感人群也可以佩戴N95口罩以减少感染风险。