Haze update Sept 26: Air quality inches towards unhealthy range again, 24-hour PSI forecast at moderate to low-unhealthy

Air quality inched towards unhealthy levels on Saturday (Sept 26) afternoon, but has remained in the moderate range, for now.

At 6pm, the 24-hour Pollutant Standards Index (PSI) ranged from 71 to 96 — in the moderate range — with central Singapore recording the highest reading of 96.

Readings of between 101 and 200 denote the unhealthy range.

Meanwhile, one-hour PM2.5 is in the normal band in northern (46), western (48) and southern (54) Singapore; but in the elevated band in central (96) and eastern (76) regions of the Republic.

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

It pointed out that moderate to dense smoke haze from fires in Kalimantan drifted towards Singapore on Saturday, while smoke plumes were also observed from fires in southern Sumatra.

Along with the prevailing south-easterly or south-westerly winds, there could be a risk of smoke haze affecting Singapore, the agency explained.

It also noted that dry conditions are expected to continue over southern Sumatra and the southern and eastern parts of Kalimantan.

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.

When PM2.5 readings are in the elevated band, members of the public should reduce strenuous outdoor activity for the next hour.

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.

9月26日（星期六）下午，空气质量一度逼近不健康水平，但目前仍处于中等水平。

下午 6 点，24 小时污染物标准指数 (PSI) 介于 71 至 96 之间——处于中等范围——其中新加坡中部地区记录到最高读数 96。

读数在 101 到 200 之间表示不健康范围。

与此同时，新加坡北部（46）、西部（48）和南部（54）地区的一小时 PM2.5 浓度处于正常范围内；但中部（96）和东部（76）地区的一小时 PM2.5 浓度处于偏高范围内。

国家环境局（NEA）在周六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）预计将处于中度至轻度不健康范围。

报告指出，周六加里曼丹岛火灾产生的中度至重度烟霾飘向新加坡，同时苏门答腊南部火灾也产生了烟柱。

该机构解释说，由于盛行东南风或西南风，新加坡可能会受到烟霾的影响。

报告还指出，苏门答腊南部以及加里曼丹南部和东部地区预计将持续干旱。

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。

当 PM2.5 读数处于较高水平时，公众应在接下来的一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。