The route of exposure affecting the respiratory tracts associated with ill effects is

• A. absorption
• B. ingestion
• C. inhalation
• D. inJECTION

Answer: (C)

Inhalation is the route that directly involves the respiratory tract. When a person breathes in airborne chemicals, vapors, fumes, or dust, those substances come into contact with the nose, throat, and lungs right away, causing irritation, coughing, shortness of breath, or chemical injury. This is why inhalation is the exposure path most associated with ill effects to the respiratory system.

Other routes—absorption through the skin, ingestion via the mouth, and injection into the bloodstream—tend to affect the body in ways not primarily tied to the respiratory tract. They involve different tissues and systems (skin absorption, gastrointestinal effects, or systemic distribution), rather than direct irritation of the airways.