Question

Particulates of ........... size pose greatest risk to human health.

• A. Less than $7.5$ micrometers in diameter
• B. Less than $2.5$ micrometers in diameter
• C. Less than $4.5$ micrometers in diameter
• D. Less than $3.5$ micrometers in diameter

Answer 1

Answer: (B)

Correct answer is (b) Less than $2.5$ micrometers in diameter