Most people are aware of the potential dangers of pesticide
use. However, understanding that pesticides can be harmful to
human health is one thing; knowing how they work is
1. Most pesticides can enter the body through
the skin, lungs or mouth. If pesticides are eaten the muscular
action of the esophagus carries them to the stomach.
2. From the stomach, the pesticide enters the
small intestine. It then enters the blood through the villi
of the small intestine. Regardless of how a pesticide enters the
body, it always winds up in the blood.
3. Blood from the small intestine is carried to
the liver. Liver cells change the chemical nature of foreign
chemicals, and this often has the effect of reducing the toxicity. These
chemical reactions are called metabolism. During metabolism the chemical structure of the
pesticide is changed and the modified pesticide is then called a
In the case of some pesticides, the process of metabolism
actually causes a nontoxic pesticide to become a toxic metabolite.