API readings unhealthy across Klang Valley and Peninsular Malaysia
Air quality deteriorated across large parts of Peninsular Malaysia on the morning of Sept 15, with the Klang Valley among the hardest hit. Serian in Sarawak recorded the highest API at 188, while Johan Setia in Selangor hit 182 and Cheras in Kuala Lumpur 172. The Department of Environment's API system classifies readings above 100 as unhealthy.