Haze update for Sept 14: Singapore's air quality forecast to remain at high moderate to mid-unhealthy levels

Air quality in Singapore dipped into the unhealthy range in some areas on Monday (Sept 14), with unhealthy 24-hour Pollutant Standard Index (PSI) readings recorded in the central, eastern and western regions between 4pm and 5pm.

At 6pm, the 24-hour PSI was between 88 and 120, placing Singapore's overall air quality in the moderate to unhealthy range, while the highest 1-hour PM2.5 reading was 121 in central Singapore.

Readings between 51 and 100 denote the moderate range, while readings of 101 to 200 indicate unhealthy air quality.

Meanwhile, one-hour PM2.5 readings remained in the elevated band for all regions in Singapore.

The country's 24-hour PSI forecast is expected to be in the high moderate to mid-unhealthy range over the next 24 hours.

Explaining this in its daily haze situation update on Monday evening, NEA said that moderate to dense smoke plumes from fires in Kalimantan drifted towards Singapore on Monday.

This, it said, is due to a shift in the prevailing winds to east-southeasterly directions, adding that smoke haze was also observed drifting from southern Sumatra.

On its haze microsite, NEA also said that some air quality stations in Kalimantan and Sumatra are reporting unhealthy to hazardous levels.

In its forecast, the agency said that dry weather conditions are expected over Singapore and the surrounding region in the coming days.

With prevailing winds forecast to continue blowing from the southeast to east-southeast, Singapore is likely to remain affected by smoke haze, NEA said.

What the PM2.5 readings mean for outdoor activities

PM2.5 indicates the level of fine micro-pollutants in the air and 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.

However, if readings hit the high-band, all healthy persons should avoid strenuous outdoor activity for the next hour, while vulnerable persons should avoid all 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.

周一（9月14日），新加坡部分地区的空气质量降至不健康水平，下午4点至5点之间，中部、东部和西部地区的24小时污染物标准指数（PSI）读数均达到不健康水平。

下午 6 点，24 小时 PSI 值在 88 到 120 之间，表明新加坡的整体空气质量处于中等到不健康范围内，而新加坡中部地区 1 小时 PM2.5 读数最高为 121。

读数在 51 到 100 之间表示空气质量中等，而读数在 101 到 200 之间表示空气质量不健康。

与此同时，新加坡所有地区的PM2.5一小时读数仍处于较高水平。

预计未来 24 小时内，该国的 24 小时 PSI 指数将处于中度偏高到中度偏不健康的范围内。

新加坡国家环境局（NEA）在周一晚间的每日雾霾情况通报中解释说，加里曼丹岛火灾产生的中等至浓烟于周一飘向新加坡。

报告称，这是由于盛行风向转为东南偏东风，并补充说，还观察到有烟霾从苏门答腊南部飘来。

国家环境局在其雾霾专题网站上还表示，加里曼丹和苏门答腊的一些空气质量监测站报告称，空气质量已达到不健康甚至危险的水平。

该机构在预报中表示，未来几天新加坡及周边地区预计将出现干燥天气。

新加坡国家环境局表示，由于预计盛行风向将继续从东南吹向东南偏东，新加坡可能仍将受到烟雾的影响。

PM2.5读数对户外活动意味着什么

PM2.5 表示空气中细小污染物的含量，是当前空气质量的重要指标——尤其是在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。

但是，如果读数达到高值，所有健康的人在接下来的一个小时内都应该避免剧烈的户外活动，而易感人群应该避免所有户外活动。

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。