Which of the following routes refers to contact through the skin?

The route that refers to contact through the skin is dermal. When a substance is applied directly to the skin, it can be absorbed into the bloodstream or affect the local area where it is applied. This is particularly relevant in the context of pesticide application, where dermal exposure may occur if the pesticide comes into contact with the skin during handling or application. Understanding dermal exposure is crucial in assessing potential health risks and implementing safety measures to minimize contact with skin when using pesticides.

Inhalation refers to the breathing in of substances, ingestion involves consuming substances, typically through the mouth, and intramuscular is a method of delivering substances directly into a muscle. Each of these routes involves different pathways and mechanisms of absorption and does not pertain to direct skin contact.