Only Particles Smaller Than ________ μM in Diameter Reach the Lungs

Question

Only particles smaller than ________ μm in diameter reach the lungs.
A) 10
B) 20
C) 30
D) 40

Accepted Answer

The size of particles that reach the lungs is determined by their aerodynamic diameter, which accounts for both the particle's size and its ability to remain suspended in the air. Particles smaller than 10 μm in diameter can penetrate deep into the lungs and are considered respirable. Choices B, C, and D are larger than 10 μm and would be filtered out by the respiratory system before reaching the lungs.