How Small is PM2.5?
Fine particulate matter compared to common particles (in micrometers, μm)
Human Hair
70μm
Visible to naked eye
Pollen
30μm
Major hay fever trigger
Dust Mite
25μm
Allergen source
Mold Spore
10μm
Triggers asthma
PM10
10μm
Coarse particles
Bacteria
5μm
Airborne pathogens
PM2.5
2.5μm
Deep lung penetration
Virus
0.1μm
Ultrafine particles
Why PM2.5 is Dangerous
- •So small they bypass nose and throat defenses
- •Penetrate deep into lung alveoli (air sacs)
- •Can cross into bloodstream
- •Cause systemic inflammation
- •Linked to heart disease, stroke, dementia
What Captures PM2.5?
- ✓HEPA H13: 99.95% of particles 0.3μm+
- ✓MERV-16: 95% of particles 0.3-1.0μm
- ✓MERV-13: 85% of particles 1-3μm
- △Standard masks: Variable, often poor fit
- ✗Regular HVAC: MERV-8 misses most PM2.5
PM2.5 Sources
🚗
Vehicle exhaust
🔥
Wood burning
🍳
Cooking
🏭
Industry
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