KUALA LUMPUR, Oct 7 — Air quality across Malaysia deteriorated further late this afternoon, with 37 monitoring stations nationwide recording readings in the unhealthy bracket as of 4.30pm, according to Department of Environment (DoE) surveillance data.

The figure marks an increase from the 32 affected stations reported during the department’s 9am morning update.

Johan Setia in Selangor recorded the nation’s highest Air Pollutant Index (API) reading at 190, holding steady from its morning level and remaining just ten points shy of the 201 threshold that triggers a “very unhealthy” categorisation.

Cheras in Kuala Lumpur followed closely behind with an API reading of 187, while Nilai in Negeri Sembilan registered 185, Putrajaya posted 183, and Batu Muda in Kuala Lumpur recorded 180.

Batu Pahat in Johor, which logged the country’s worst air quality at 197 in the morning, showed modest improvement by late afternoon, easing to 179 to rank sixth nationwide.

Greater Klang Valley shrouded in smog

The Greater Klang Valley urban belt saw extensive haze coverage, accounting for nine unhealthy stations across Selangor, Kuala Lumpur, and Putrajaya.

In Selangor, six stations logged elevated pollution levels. Beyond Johan Setia, unhealthy air quality was recorded in Shah Alam (177), Petaling Jaya (174), Banting (172), Klang (170), and Kuala Selangor (153).

In the Federal Territories, both Kuala Lumpur stations remained in the high unhealthy range with Cheras at 187 and Batu Muda at 180, while the administrative centre of Putrajaya stood at 183.

Johor recorded the highest number of affected monitoring points of any state, with eight stations in the unhealthy band. Following Batu Pahat, elevated readings were registered in Segamat (178), Pasir Gudang (176), Larkin (172), Tangkak (169), Pengerang (166), Kota Tinggi (166), and Kluang (164).

In Negeri Sembilan, Nilai led with 185, followed by the state capital Seremban at 175 and coastal Port Dickson at 166.

All three monitoring stations in Melaka recorded unhealthy conditions: Bukit Rambai (176), Bandaraya Melaka (174), and Alor Gajah (172).

On the east coast of the peninsula, Pahang logged five affected locations, comprising Rompin (165), Temerloh (164), Indera Mahkota in Kuantan (159), Balok Baru in Kuantan (155), and Jerantut, which improved markedly to 105 from 159 in the morning.

In Terengganu, industrial hubs Kemaman and Paka both registered 153, while state capital Kuala Terengganu logged 134.

In Perak, four stations remained in the unhealthy category: Tasek Ipoh at 155 (down from 174 at 9am), Seri Manjung and Tanjung Malim tied at 154, and Pegoh Ipoh at 151.

Elsewhere, Tawau in Sabah registered 156, while Sungai Petani in Kedah logged the lowest reading on the national unhealthy list at 107.

Under the DoE’s API scale, readings between 0 and 50 are categorized as good, 51 to 100 as moderate, 101 to 200 as unhealthy, 201 to 300 as very unhealthy, and 301 and above as hazardous.