KUALA LUMPUR, Oct 8 — The Department of Environment (DOE) has clarified that higher air quality figures displayed on independent mobile applications and third-party websites do not reflect data suppression or inaccuracies in official records
Just as 38 areas in Malaysia logged unhealthy air quality today, the department explained that Malaysia’s Air Pollutant Index (API) and commercial Air Quality Index (AQI) platforms frequently show divergent numbers because they rely on different index scales, mathematical models, concentration thresholds, averaging durations, update intervals, and sensory inputs.
Many international applications employ the US AQI standard or rely on low-cost uncalibrated sensors, predictive computational models, or satellite imagery.
Satellite monitoring, the DOE pointed out, evaluates total aerosol column density across the upper atmosphere rather than air quality at ground level where human respiration occurs. Importantly, satellite sensors can misidentify atmospheric cloud cover or water vapour as particulate haze.
The department stressed that valid comparisons between platforms cannot be drawn from single headline figures alone, but must match identical geographic coordinates and time stamps, direct pollutant concentrations, and specific indexing methodologies.
The DOE advised the public to rely on verified data from the Air Pollutant Index Management System (APIMS) web portal or the MyJAS EQMS mobile application.
These platforms update hourly and serve as the government’s official benchmark for health advisories and disaster response protocols.
Malaysia’s national API is calculated using continuous measurements of six core criteria pollutants, with fine particulate matter (PM2.5) acting as the dominant driver during haze events.
The system draws data from 68 continuous monitoring stations nationwide that comply with strict ISO standards and US Environmental Protection Agency guidelines.
Unhealthy air quality blankets 38 areas
As of 3pm today, no monitoring stations in the country recorded good air quality, with 30 stations registering moderate levels and 38 falling into the unhealthy category (API 101 to 200).
Southern and central states recorded the most severe pollution levels, led by Segamat at 190, Seremban at 186, Nilai at 185, and Kluang at 181. Rompin in Pahang and peat fire hotspot Johan Setia in Selangor each logged 178, while the administrative centre of Putrajaya recorded 175.
Across the Greater Klang Valley, elevated readings were recorded in Cheras (174), Shah Alam (171), and Petaling Jaya (165). Unhealthy air quality was also recorded across monitoring stations in Kedah, Penang, Perak, Melaka, and Terengganu, where Paka registered the lowest reading in the unhealthy bracket at 126.
The DOE attributed the deteriorating air quality to prolonged dry spells across the southern Asean region.
Citing data from the Asean Specialised Meteorological Centre (ASMC), the department noted that 210 fire hotspots were detected in Sumatra and 94 in Kalimantan on Oct 7, compared to just one localized hotspot in Pahang, Malaysia.
The ASMC observed moderate to dense transboundary smoke plumes drifting across central and southern Sumatra, Singapore, and southern Peninsular Malaysia.
Under the National Haze Action Plan, all outdoor school activities must be suspended immediately when local API readings surpass 100. Should readings exceed the 200 threshold, schools, kindergartens, and daycare centres are ordered to close.
If API levels remain consistently above 150 for more than 24 hours, the National Disaster Management Agency (Nadma) convenes its disaster coordination committee to assess cloud seeding operations, subject to suitable atmospheric moisture and cloud conditions.
