Taking care not to eat, drink, smoke or apply cosmetics in a contaminated area will help prevent exposure via which route of entry?

The correct answer is ingestion. When operating in a contaminated area, it's crucial to avoid eating, drinking, smoking, or applying cosmetics because these activities can lead to the direct ingestion of hazardous substances. If contaminants are present on hands, surfaces, or food and drinks, they can easily enter the body through the mouth. This route of entry is particularly concerning because it allows toxic substances to bypass protective barriers, potentially resulting in harmful health effects.

Ingestion is a significant concern in hazardous waste operations because, unlike inhalation or absorption, which often require the substance to enter through the respiratory system or through skin contact, ingestion involves substances directly entering the digestive system. This makes understanding safe practices in contaminated areas vital for operational safety.

Other routes of entry, such as inhalation, absorption, and injection, refer to different mechanisms through which hazards can enter the body, but the specific activities mentioned in the question directly relate to preventing ingestion.