How does inhalation as a route of exposure occur?

Inhalation as a route of exposure involves the process of breathing in substances, which can include gases, vapors, or airborne particles. When an individual inhales, air is drawn into the lungs, where any contaminants present in the air can be absorbed through the lung tissue. This route is particularly significant for many chemicals and biological agents because substances that are inhaled can enter the bloodstream quickly, bypassing some of the body's natural barriers, and can lead to rapid systemic effects.

The process is distinct from other routes of exposure, such as skin contact, swallowing, or injection. Skin contact involves absorption through the skin, which is a different mechanism and often requires different considerations. Swallowing refers to ingestion, where substances enter the digestive system rather than the respiratory system. Injection introduces substances directly into the body through a needle, bypassing the respiratory system altogether. Each of these routes of exposure has unique pathways and implications for how substances affect the body, making inhalation a critical route to be aware of in both medical and hazardous environments.