Human Health Effects of Pesticides

Pesticides are designed to poison and kill. Many are designed to operate on the nervous or reproductive systems of pests by disrupting normal functions – functions that are shared by humans. Exposure to pesticides can cause both short-term and long-term health effects, depending on the chemical and the nature of the exposure.

Acute, high-dose exposures in humans can result in symptoms in humans that are similar or identical to those induced in the target pest. These symptoms may include labored breathing, headaches, rash, eye and skin irritation, wheezing, faintness, seizures, coma, and even death.

Prolonged exposure to pesticides, even at very low levels, is known as chronic exposure. Over time, someone who is regularly exposed to pesticides, even in very small doses, may experience serious health problems, such as fatigue, neurological disorder, depression, increased chemical sensitivity, chronic cough, and some forms of cancer.

For children, regular exposure to pesticides can seriously damage cognitive skills and lower IQ.

Pregnant women are especially at risk for such effects as birth defects and reproductive disorders.

The effects of chronic exposures may not appear for years, and are usually very difficult to trace to specific exposures.

Children face an even greater risk from pesticide exposure.

  • A 2001 study at the University of Washington found that 99% of children tested had detectable levels of organophosphate pesticides in their bloodstreams.

  • Children of mothers who regularly used pesticides outside of their home were nine times more likely to develop leukemia.

  • Over 300 pesticides are approved for use on food; more than 60 are known or suspected to cause cancer.

  • 55% of the lifetime risk from exposure to cancer-causing pesticides used on fruits and vegetables is incurred by the age of six.

  • As many as 6,200 of the current preschool generation are projected to get cancer from pesticide exposure.

For more information on the health effects of pesticides, see our links page and our pesticide fact sheets.