Which is not one of the four primary routes of pesticide exposure?

The correct choice is linked to understanding how pesticides enter the body. The four primary routes of pesticide exposure are dermal, oral, inhalation, and ocular. Dermal exposure occurs when pesticides contact the skin, oral exposure happens through ingestion, and inhalation occurs when pesticides are breathed in.

Fumigation, on the other hand, refers to a method of applying pesticides in a gaseous form or vapor. While it is a technique used for pest control, it does not represent a route of exposure but rather a method of application. This distinction clarifies why fumigation is not categorized alongside the main routes of exposure, which define how a pesticide interacts with a biological system once applied. Recognizing these differences is crucial for effective safety measures and understanding the risks associated with pesticide use.