Worsening transboundary haze has forced the temporary closure of 591 schools across 10 districts in Sarawak, affecting nearly 200,000 students, as air pollution in parts of the state reached “very unhealthy” levels and renewed concerns over Southeast Asia’s recurring haze challenge.
The closures involved 509 primary schools and 82 secondary schools, affecting a total of 197,323 students. Home-based teaching and learning was implemented during the closure period to ensure lessons could continue while limiting students’ exposure to deteriorating outdoor air quality.
Serian Records ‘Very Unhealthy’ Air Quality
Serian, located near the border with Indonesia’s Kalimantan, emerged as the worst-affected area. Its Air Pollutant Index (API) reached 239 on the morning of August 21, placing air quality firmly within the “very unhealthy” category.
Other parts of Sarawak were also affected, with unhealthy readings recorded in areas including Sri Aman, Kuching, Samarahan, Sarikei, Sibu and Bintulu. Under Malaysia’s API classification, readings between 101 and 200 are considered unhealthy, while 201 to 300 are classified as very unhealthy.
The school closures covered institutions under the district education offices of Kuching, Padawan, Bau, Lundu, Samarahan, Simunjan, Serian, Sri Aman, Lubok Antu and Betong.
The Sarawak Education Department said the precautionary measure was intended to protect the health, safety and welfare of students and education personnel.
Thousands of Hotspots Detected Across Kalimantan
Regional monitoring indicates that the haze affecting Sarawak is closely linked to extensive fire activity across neighbouring Kalimantan.
According to data cited by Sarawak’s Natural Resources and Environment Board from the ASEAN Specialised Meteorological Centre (ASMC), 7,286 hotspots were detected in Kalimantan between August 1 and 19, compared with 148 in Sarawak during the same period.
Moderate to dense smoke originating from West Kalimantan was observed drifting northwards into western Sarawak, illustrating how forest and land fires can quickly develop into a cross-border environmental challenge.
Prolonged dry conditions have further increased the risk of fires and haze, with regional authorities warning that conditions could continue to deteriorate in fire-prone areas if dry weather persists.
A Regional Environmental and Public Health Challenge
The latest episode once again demonstrates why transboundary haze remains one of ASEAN’s most persistent environmental challenges.
Forest and peatland fires during extended dry periods can generate smoke capable of travelling hundreds of kilometres across national borders. The resulting pollution can affect public health, education, transportation, tourism and economic activity across several countries simultaneously.
Children are particularly vulnerable to prolonged exposure to polluted air, making the closure of schools an important preventive measure when pollution reaches severe levels.
The impact in Sarawak also illustrates how environmental events occurring on one side of a national border can rapidly affect communities elsewhere, reinforcing the need for coordinated prevention and response mechanisms across ASEAN.
Malaysia Steps Up National Response
Malaysia’s Department of Environment (DOE) has activated both the National Open Burning Action Plan and National Haze Action Plan, while increasing enforcement activities, patrols and monitoring in areas vulnerable to open burning.
Authorities have urged the public to avoid open burning and report fires, while environmental agencies continue monitoring air quality, weather patterns and regional hotspots.
Sarawak authorities have similarly advised residents to limit unnecessary outdoor exposure during periods of unhealthy air quality and take appropriate precautions when outside.
The response highlights the importance of addressing both immediate public-health risks and the underlying sources of haze.
Malaysia Calls for Stronger ASEAN Action
The worsening conditions have also pushed the issue back onto ASEAN’s regional agenda.
Malaysia has indicated that it will use ASEAN diplomatic channels to address the transboundary haze, with Foreign Minister Datuk Seri Mohamad Hasan describing ASEAN as the appropriate mechanism for resolving issues involving countries within the region.
Natural Resources and Environmental Sustainability Minister Datuk Seri Arthur Joseph Kurup has also urged ASEAN member states to strengthen preventive measures, hotspot surveillance, enforcement against open burning and firefighting preparedness as dry conditions increase regional haze risks.
Malaysia reaffirmed its commitment to the regional objective of achieving a haze-free ASEAN by 2030 through implementation of the ASEAN Agreement on Transboundary Haze Pollution (AATHP).
ASEAN Cooperation Faces a Critical Test
The latest haze episode highlights both the importance and the limitations of regional environmental cooperation.
ASEAN already possesses mechanisms for information sharing, hotspot monitoring and cooperation on transboundary haze. However, the recurring nature of the problem demonstrates the difficulty of translating regional commitments into consistent prevention and enforcement across national jurisdictions.
The South China Morning Post noted concerns that ASEAN’s consensus-based approach can limit the effectiveness of collective responses to recurring haze episodes.
Addressing the problem therefore requires more than responding after smoke crosses borders. Long-term progress depends on preventing forest and peatland fires, strengthening land-management practices, improving enforcement and ensuring rapid coordination when regional fire risks increase.
Climate Conditions Could Intensify Future Risks
The situation also comes amid concern over increasingly challenging climatic conditions.
Malaysia has warned that El Niño is expected to strengthen gradually in the coming months, potentially increasing dry-weather conditions and the risk of fires across vulnerable areas of Southeast Asia.
This adds urgency to regional preparedness.
As climate variability increases the likelihood of prolonged dry periods, ASEAN countries may need to strengthen early-warning systems, firefighting capabilities, cross-border information sharing and preventive land-management measures before haze reaches populated areas.
Looking Ahead
The closure of 591 schools and disruption to the education of 197,323 students demonstrates that transboundary haze is far more than an environmental issue. It carries immediate consequences for public health, education and everyday life across Southeast Asia.
For ASEAN, the latest Sarawak haze episode provides another reminder that environmental challenges crossing national borders require equally coordinated regional solutions.
Stronger prevention, faster information sharing, effective enforcement and sustained cooperation under the ASEAN Agreement on Transboundary Haze Pollution will be crucial if the region is to achieve its ambition of becoming haze-free by 2030.
As Sarawak continues monitoring air quality and regional fire activity, the immediate priority remains protecting affected communities. Longer term, the challenge for ASEAN will be ensuring that recurring haze episodes become less frequent, less severe and ultimately preventable.
