What type of exposure does inhalation refer to?

Inhalation specifically refers to the act of breathing in substances, which can include air, gases, vapors, or aerosols. This process involves drawing these substances into the lungs through the respiratory system. When discussing exposure types, inhalation is distinctly characterized as a route through which harmful substances can enter the body, potentially leading to health issues.

In contrast, the other options do not relate to inhalation. Touching refers to dermal contact, swallowing involves ingestion, and injecting pertains to the use of needles or syringes. Each of these pathways represents different mechanisms of exposure, but inhalation is uniquely tied to respiratory intake. Understanding these distinctions is crucial in fields such as health and safety, where recognizing how substances can enter the body helps in implementing appropriate controls and protective measures.