Pesticides are substances or mixtures intended for preventing, destroying, repelling or mitigating any pest.

While pesticides can be useful for protecting produce, they can cause harm to humans, animals and the environment because they are essentially designed to kill microorganisms and pests. Depending on the type of pesticide, they can affect the nervous system, irritate the skin and eyes, affect the hormone or endocrine system and after long-term exposure pesticides can be carcinogenic.

To learn more, go to:
http://www.epa.gov/opp00001/about/index.htm