Question

Statement I: Fraction of airborne dust which enters the body but is trapped in nose, throat and upper respiratory tract is called inhalable dust.
Statement II: Dust particles of size lesser than 5 \(\mu\)m are categorized as inhalable dust.
In light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

Inhalable dust: larger particles trapped in upper respiratory tract.
Respirable dust: smaller particles (\(<\) 5 \(\mu\)m) that reach the lungs.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
We need to understand the definition of inhalable dust.
It is related to the particle size and where it gets trapped in the respiratory system.

Step 2: Key Formula or Approach:
No specific formula.
Need to know the definitions of inhalable and respirable dust.

Step 3: Detailed Explanation:
Inhalable dust is the fraction of airborne dust that enters the body and is trapped in the nose, throat, and upper respiratory tract.
This is Statement I, which is correct.
Dust particles of size lesser than 5 \(\mu\)m are categorized as respirable dust, not inhalable dust.
Inhalable dust typically has a larger size range.
Thus, Statement II is false.

Step 4: Final Answer:
Statement I is true, but Statement II is false.
Hence, the correct option is (C).