Why Does Toxic Dust Surge Even in Good Weather?
Created By RISC | 3 weeks ago
Last modified date : 3 weeks ago
Ever wondered why toxic dust levels can be high even in cool weather?
Thailand—especially Bangkok and its metropolitan areas—has been grappling recently with persistently high levels of PM2.5 fine particulate matter. This severe air pollution crisis is significantly impacting public health and quality of life. While air quality has improved at times, PM2.5 levels often spike again unexpectedly.
Where does this dust come from?
- Open Burning: One of Thailand’s primary sources of PM2.5 pollution is open burning, including agricultural burning (such as cornfields), waste incineration, and forest fires. According to the Pollution Control Department (PCD), open burning both within Thailand—particularly in the northern and northeastern regions during the dry season—and in neighboring countries contributes significantly to PM2.5 levels. Seasonal winds carry these pollutants southward into Bangkok and surrounding provinces. Additionally, burning activities in nearby provinces such as Samut Prakan, Nakhon Pathom, and Pathum Thani, where waste and agricultural residues are frequently burned, further exacerbate the issue.
- Traffic Emissions: In Bangkok, traffic emissions contribute to 51% of total PM2.5 pollution, with diesel-powered vehicles being the primary culprits. Heavy traffic congestion, especially during rush hours, traps pollutants in the lower atmosphere, particularly in areas with poor ventilation, such as city centers.
- Industrial Activities: Bangkok’s neighboring industrial zones, including Bang Phli, Bang Pu, and Lat Krabang, house numerous factories that emit pollutants into the air. Research from the Asian Institute of Technology (AIT) indicates that industrial emissions account for 25-30% of PM2.5 pollution in Bangkok.
- Meteorological Conditions: Weather patterns play a crucial role in worsening air pollution, particularly during the cool season. A phenomenon called the “Inversion Layer” occurs when colder air near the ground is trapped beneath warmer air above, preventing pollutants from dispersing into the upper atmosphere. This effect essentially creates a "pollution dome," locking PM2.5 within the city and leading to dangerously high pollution levels.
How can we protect ourselves?
- Monitor air quality in real time using apps like AirVisual or Air4Thai to plan daily activities based on pollution levels.
- Wear effective masks such as N95, KN95, or high-quality fabric masks to protect against PM2.5. Be cautious, as some masks are not designed to filter fine particles effectively.
- Limit outdoor activities during high pollution periods. If PM2.5 levels exceed safe limits, avoid outdoor exercise and opt for indoor workouts instead. Using an air purifier indoors can also help maintain healthier air quality.
Story by Phetcharin Phongphetkul, Sustainable Designer, LEED®AP BD+C, WELLTM AP, Fitwel Ambassador, ActiveScore AP, TREES-A NC, RISC
Reference by
Pollution Control Department. (2023). รายงานสถานการณ์มลพิษของประเทศไทย ปี 2566 [Thailand State of Pollution Report 2023]. Bangkok: Ministry of Natural Resources and Environment. Retrieved from https://www.pcd.go.th/publication/32171/
Asian Institute of Technology. (2024, January 26). Collaborative efforts for cleaner air in Bangkok and beyond. AIT. Retrieved from https://ait.ac.th/2024/01/collaborative-efforts-for-cleaner-air-in-bangkok-and-beyond/
World Health Organization. (2021). Global air quality guidelines: Particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide. Geneva: World Health Organization. Retrieved from https://www.who.int/publications/i/item/9789240034228