What occurs when people come in direct contact with a harmful agent at or near an incident?

The correct choice is based on the definition of contamination in the context of harmful agents. When individuals come into direct contact with a harmful agent, this situation is defined as contamination. Contamination refers to the presence of harmful substances in or on a person's body or on materials that may pose a risk to health or safety.

Contamination can occur through various means including touching, inhaling, or being splashed by these harmful agents. This term encompasses scenarios where a person’s skin, clothing, or equipment becomes tainted with hazardous materials.

While exposure describes the act of being in proximity or being subjected to a harmful agent, it does not necessarily imply direct contact. Ingestion refers specifically to consuming a harmful substance, which is not applicable in every scenario of direct contact. Infection generally arises when harmful microorganisms enter the body and begin to multiply, which would not encompass all scenarios of direct contact with harmful agents, especially those that may not be infectious in nature.

Therefore, the concept of contamination precisely captures the situation of direct contact with harmful agents.