Challenging the fire-centric paradigm: pollution sources and health effects of PM 2.5 in Thailand

Thailand’s PM2.5 crisis has evolved into a complex environmental and public-health emergency with far-reaching socio-economic effects. This review examines key drivers of PM2.5, including agricultural biomass burning, BVOC emissions, transboundary transport, and reactions involving nitrogen fertilizers. Using field measurements, chemical source-apportionment tools, and atmospheric modelling, it shows that PM2.5 composition and toxicity vary across regions and seasons, shaped by forest fires, crop-residue burning, and fossil-fuel use. Health impacts span respiratory and cardiovascular diseases and cognitive impairment, disproportionately affecting children, the elderly, and outdoor workers. Stakeholder testimonies reveal the limitations of current top-down regulations and call for integrated solutions combining technology, economic incentives, and robust policy reform. Recommended actions include strengthened Clean Air legislation, sustainable finance mechanisms, community-scale biomass-to-energy systems, and enhanced air-quality monitoring. The paper argues that clean air must be treated as a fundamental human right, requiring coordinated national and ASEAN-regional action.