What is PM 2.5?
PM 2.5 stands for Particulate Matter 2.5, which refers to ultra-fine dust particles no larger than 2.5 microns (1 micron is one-millionth of a meter!). These tiny particles can float in the air, enter your respiratory system, and even get into your bloodstream, making them extremely harmful.
How PM 2.5 is Measured
PM 2.5 is measured in micrograms per cubic meter (µg/m³) and is often paired with the Air Quality Index (AQI):
0–50: Good – safe for everyone
51–100: Moderate – sensitive people may feel effects
101–150: Unhealthy for sensitive groups – children, elderly, respiratory patients
151–200: Unhealthy – everyone may start feeling effects
201–300: Very unhealthy – avoid going outside
300+: Hazardous – stay indoors at all costs
PM 2.5 in Thailand
PM 2.5 levels spike during winter and dry seasons (Dec–Apr) due to dry weather and stagnant air. Key causes:
Winter: Cold air traps dust near the ground
Dry season: Open burning of waste or agricultural areas
Top 5 areas with highest PM 2.5:
Bangkok – traffic congestion & open burning
Chiang Mai – forest fires
Lampang – industrial emissions
Saraburi – cement industry
Nakhon Ratchasima – agricultural burning
Health Impacts
Short-term:
Eye, nose, and throat irritation
Difficulty breathing
Worsening allergies
Temporary high blood pressure
Long-term:
Chronic obstructive pulmonary disease (COPD)
Increased risk of heart disease and stroke
Higher lung cancer risk
Delayed development in children
Cognitive decline in the elderly
How to Protect Yourself
Wear a mask: Use N95 or certified PM 2.5 masks
Stay indoors: Especially on high pollution days
Check AQI daily: Apps or websites like Air4Thai
Seal your home: Close windows/doors, block gaps with damp cloth
Use air purifiers: In bedrooms and frequently used rooms
Increase indoor greenery: Plants help reduce dust
When to See a Doctor Immediately
Seek medical attention if you experience:
Severe shortness of breath or chest pain
Dizziness or extreme fatigue
Chronic cough with blood
Pale skin or blue lips
Collective Action is Key
PM 2.5 cannot be solved by individuals alone. Everyone must contribute:
Government: Enforce anti-burning laws, reduce fossil fuel use
Private sector: Develop low-pollution tech, e.g., electric vehicles
Public: Reduce open burning, use public transport
Education: Raise awareness in schools
Global cooperation: Share technology and knowledge to reduce pollution
Example: China has successfully reduced PM 2.5 through strict measures, factory shutdowns, and promoting clean energy.
Conclusion
PM 2.5 is no longer distant—it affects everyone’s health. Protecting yourself is essential now, but long-term solutions require cooperation at personal, community, and national levels to ensure clean air for future generations.
For more information, check the Pollution Control Department and Department of Health.
Take care of yourself, stay healthy, and see you next time!
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