What is secondary contamination?

• A. Primary contamination
• B. The dilution of a contaminant
• C. A contaminated person or object contaminating someone else
• D. The purification of a contaminated area

Answer: (C)

Secondary contamination is the spread of contamination from something or someone that is already contaminated to another person or surface. It happens when a contaminated person or object transfers the contaminant to someone else, or to another area or item, through contact or exposure. This option captures the idea of onward transfer from a contaminated source, which is what secondary contamination means.

The other ideas describe different things: contamination that comes directly from the initial source is primary contamination, while dilution and purification describe reducing or removing contamination rather than transferring it to a new host or surface.