\n<\/p>\n
NEA began\u00a0issuing daily haze advisories\u00a0on Sep 4 after the 24-hour PSI in the central region crossed into the unhealthy band of 101 to 200 at 7am, marking the first time the PSI had breached the level since Oct 8, 2023. Air quality deteriorated steadily throughout the day, with the\u00a0central, eastern and western regions\u00a0all recording unhealthy PSI levels by midnight.<\/p>\n
The 24-hour PSI is Singapore’s indicator of daily\u00a0air quality\u00a0and forms the basis of NEA’s daily health advisories. It is calculated using six air pollutants – PM2.5, PM10, ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide.\u00a0<\/p>\n
The 1-hour PM2.5 reading, on the other hand, is the hourly average of the PM2.5 pollutant levels. PM2.5 is fine particulate matter with a diameter of 2.5 micrometres or shorter, and is the dominant pollutant during haze that causes harm to health.<\/p>\n
While the 24-hour PSI is an average of the past 24 hours, the one-hour PM2.5 reading reflects the air quality at a single point in time.<\/p>\n
A 24-hour PSI reading is considered “very unhealthy” when it is within the 201-300 range, and “hazardous” when it goes over 300.<\/p>\n<\/div>\n
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NEA began\u00a0issuing daily haze advisories\u00a0on Sep 4 after the 24-hour PSI in the central region crossed into the unhealthy band of 101 to 200 at…<\/p>\n","protected":false},"author":1,"featured_media":83270,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/dam.mediacorp.sg\/image\/upload\/s--t7knvJJy--\/c_crop,h_1123,w_1996,x_0,y_1\/c_fill,g_auto,h_676,w_1200\/fl_relative,g_south_east,l_mediacorp:cna:watermark:2021-08:cna,w_0.1\/f_auto,q_auto\/v1\/mediacorp\/cna\/image\/2026\/09\/04\/img_9328.jpg?itok=LiPeShlX","fifu_image_alt":"","footnotes":""},"categories":[2],"tags":[364,19471,8939,4001,3974,4575,11178,105],"class_list":["post-83269","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-buzz-news-sg-global","tag-air","tag-moderate","tag-nea","tag-quality","tag-range","tag-remain","tag-unhealthy","tag-wednesday","wpcat-2-id"],"brizy_media":[],"_links":{"self":[{"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/posts\/83269","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=83269"}],"version-history":[{"count":0,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/posts\/83269\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=\/wp\/v2\/media\/83270"}],"wp:attachment":[{"href":"https:\/\/sgbuzz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=83269"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=83269"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sgbuzz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=83269"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}