What does the term "residue" refer to concerning pesticides?

The term "residue" in the context of pesticides specifically refers to the small amounts of pesticides that may remain on or in food products after they have been treated. This includes any trace amounts that might not be fully removed during washing or processing. Understanding this concept is crucial since pesticide residues can have implications for food safety and public health, which is why there are regulations in place regarding acceptable levels.

The other options do not accurately capture the meaning of "residue." Unprocessed chemicals do not pertain specifically to the context of food safety and pesticide application. Leftover equipment can refer to various aspects of the pesticide application process but does not relate to food products or safety. Contaminant levels may involve more than just pesticide residues and could include various substances not associated with pesticides alone. Thus, the correct view aligns with the understanding of pesticide residues as relevant to food consumption and safety.