The principal routes of industrial exposure are dermal and inhalation. Which statement is true?

• A. Inhalation and ingestion
• B. Dermal and ingestion
• C. Inhalation and gamma rays
• D. Dermal and inhalation

Answer: (D)

Industrial exposure to hazardous substances mainly happens through skin contact and by breathing them in. Dermal absorption lets chemicals pass through the skin, while inhalation brings vapors, gases, or aerosols into the lungs where rapid uptake can occur. Ingestion can occur, but it is typically a secondary route, often resulting from hand-to-mouth transfer rather than a primary pathway in most industrial settings. Gamma rays are not a chemical exposure route at all; they involve ionizing radiation, not chemical absorption through skin or lungs.

So, the statement that identifies dermal and inhalation as the principal routes is the true one because those two pathways are the main ways chemicals enter the body in most workplaces.