Which exposure route involves inhalation of air containing aerosols, vapors, or gases?

• A. Inhalation
• B. Injection
• C. Dermal
• D. Ingestion

Answer: (A)

Inhalation is the exposure route that occurs when you breathe air that carries aerosols, vapors, or gases. Aerosols are tiny solid or liquid particles suspended in air, vapors are the gaseous forms of substances that are liquids or solids at room temperature, and gases are substances already in the gaseous state. When these contaminants are inhaled, they can deposit in the nose, throat, or lungs, potentially causing irritation, respiratory conditions, or systemic effects after absorption into the bloodstream. The respiratory system is the primary interface with the workplace environment, so inhalation is a major pathway for many airborne hazards. The other routes involve entry through the skin (dermal), swallowing (ingestion), or a puncture into the body (injection), which do not describe breathing contaminated air.