Cd29 Nonoparticles

Question 1

Particles ≤100 nm in at least one dimension are nanoparticles. When inhaled, why do these particles generally result in greater pulmonary inflammation than an equal mass of larger size particles?
A. nanoparticles have a significantly greater surface area to mass ratio
B. nanoparticles deposit deeper in the respiratory tract than larger sized particles
C. nanoparticles are generally more water soluble than larger particles
D. nanoparticles reduce the clearance capability of alveolar macrophages

Answer 1

A. nanoparticles have a significantly greater surface area to mass ratio

Explanation and Reference:
The toxicity of nanoparticles is attributed primarily to the increased surface area that can generate secondary reactions (oxidative stress) or carry co-pollutants into the lung. They have no effect on macrophages but may not be effectively cleared by these cells. They do not necessarily deposit deeper in the lungs, depending on their shape. Since most nanoparticles are carbon fibers or metals, it would be incorrect to characterize them generally as “water soluble.” C&D 8th, p. 703