Which organ metabolizes most pesticides and excretes degraded products?

• A. Kidney
• B. Heart
• C. Lungs
• D. Liver

Answer: (D)

The liver is the main organ for metabolizing pesticides because it houses the detoxification systems that modify chemicals to make them easier to eliminate. Enzymes in the liver, especially the cytochrome P450 family, perform reactions that transform pesticides through oxidation, reduction, and conjugation (like glucuronidation and sulfation). These steps change lipophilic compounds into more water-soluble forms, preparing them for excretion. After metabolism, these degraded products can be excreted via bile into the digestive tract or released into the bloodstream for removal by the kidneys. While the kidneys and lungs participate in elimination to some extent, and the heart doesn’t play a detoxification role, the liver carries out the bulk of pesticide metabolism.