PM2.5 particles in ambient air are more harmful than PM10 because they:

• A Have a larger surface area for gas absorption
• B Deposit in upper airways causing rhinitis
• C Penetrate deep into alveoli and may enter systemic circulation ✓
• D Are filtered by nasal hair (vibrissae) and turbinates

Explanation

PM2.5 (particles ≤2.5 µm aerodynamic diameter) are fine particles that bypass upper airway defences and deposit in the terminal bronchioles and alveoli; they can translocate into the systemic circulation causing cardiovascular, metabolic, and systemic effects. PM10 largely deposits in the upper airways and trachea. PM2.5 is therefore more associated with cardiovascular mortality than PM10.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.