Haze update for Sept 4: 24-hour PSI forecast to be in moderate to unhealthy range

Singapore's 24-hour Pollutant Standard Index (PSI) on Friday (Sept 4) morning entered into the unhealthy range for the first time since Oct 8, 2023, prompting the National Environment Agency (NEA) to begin daily haze advisories .

This includes the 24-hour PSI forecast for members of public to plan their activities and events for the next 24 hours, the agency said in an update just before noon on Friday.

In its first forecast on Friday evening, NEA said dry conditions are expected to continue for the coming days, adding that Singapore may continue to be affected by transboundary haze under the prevailing south-easterly or southerly winds, if the fires in the southern and central parts of Sumatra and various parts of Kalimantan persist.

It also forecast the 24-hour PSI for Singapore to be in the higher end of the moderate to the middle of the unhealthy range.

Checks on NEA's haze microsite indicate that the 24-hour PSI reading of 116 for the central region remains in the unhealthy range.

Across the north, east, south and west regions, PSI remains in the moderate range, with regions in the east and west having readings of 98 and 95 respectively — that borders the on unhealthy range.

NEA said that the health impact of haze is dependent on one's health status, the PSI level, and the length and intensity of outdoor activity.

It advised those who are immediately planning to conduct or participate in outdoor activities to check the 1-hour PM2.5 concentration readings and person guide.

Meanwhile, those who are planning for outdoor activities for the next day should use the 24-hour PSI forecast and the corresponding health advisories for planning.

Category-based advisory

Based on the 24-hour-PSI forecast on Friday, healthy persons can continue with normal activities if PSI remains in the moderate range.

However, they should reduce prolonged or strenuous outdoor physical exertion if PSI crosses into the unhealthy range.

Elderly persons, pregnant women and children can also continue with normal activities if the PSI remains in the moderate range.

They should minimise prolonged or strenuous outdoor physical exertion if the PSI is in the unhealthy range.

Those with chronic lung or heart disease may similarly continue with normal activities when the PSI is moderate.

But they should avoid prolonged or strenuous outdoor physical exertion if the PSI reading crosses into the unhealthy range.

新加坡24小时污染物标准指数（PSI）在周五（9月4日）上午首次进入不健康范围，这是自2023年10月8日以来的首次，促使国家环境局（NEA）开始每日发布雾霾预警。

该机构在周五中午前发布的最新消息中表示，其中包括未来 24 小时的 PSI 预报，供公众计划未来 24 小时的活动和事件。

新加坡国家环境局（NEA）周五晚间发布的首份天气预报称，未来几天干燥天气预计将持续，并补充说，如果苏门答腊岛南部和中部以及加里曼丹岛部分地区的火灾持续下去，在盛行的东南风或南风的影响下，新加坡可能会继续受到跨境烟霾的影响。

该机构还预测，新加坡的 24 小时 PSI 指数将处于中等偏上水平，接近不健康水平。

新加坡国家环境局的雾霾微网站显示，中部地区的 24 小时 PSI 读数为 116，仍处于不健康范围内。

在北部、东部、南部和西部地区，PSI 指数仍处于中等水平，东部和西部地区的读数分别为 98 和 95——这接近不健康范围。

新加坡国家环境局表示，雾霾对健康的影响取决于个人的健康状况、空气污染指数（PSI）以及户外活动的持续时间和强度。

它建议那些计划立即进行或参与户外活动的人查看 1 小时 PM2.5 浓度读数和个人指南。

同时，计划第二天进行户外活动的人们应该参考 24 小时 PSI 预报和相应的健康建议进行规划。

基于类别的咨询

根据周五的 24 小时 PSI 预测，如果 PSI 保持在中等范围内，健康人可以继续进行正常活动。

但是，如果 PSI 值超过健康范围，他们应该减少长时间或剧烈的户外体力活动。

如果 PSI 保持在中等范围内，老年人、孕妇和儿童也可以继续进行正常的活动。

如果 PSI 值处于不健康范围，则应尽量减少长时间或剧烈的户外体力活动。

同样，当 PSI 处于中等水平时，患有慢性肺病或心脏病的人也可以继续进行正常的活动。

但如果 PSI 读数超过健康范围，则应避免长时间或剧烈的户外体力活动。