Information on health effects of pesticides (including insecticides and weed killers) is usually buried in the medical literature, and it is not required on pesticide labels. Having studied this medical literature lately, I would like to share some of what I have learned.

Exposure to pesticides can occur by mouth, through the air or through skin contact. Sprays, foggers or bombs cause the highest human exposure.

In children there are studies that have shown developmental delays, birth defects, and cancers associated with pesticide exposure. In one study children who were exposed to insecticides in the home, including those applied by professional services, had a nearly three fold higher risk of leukemia. Another study showed that the risk for brain cancer was elevated more than 10-fold in children exposed to flea and tick pesticides used as sprays or foggers. For both leukemia and brain cancer the risk was highest if the exposure occurred during pregnancy or if the exposure was more frequent.

In adults there are studies that have linked pesticide exposure with Parkinson’s Disease, reduced fertility, and cancer. For example, the chemical 2,4-D, a weed killer used in many ‘weed and feed’ products and used by lawn services, has been associated with an increased risk of lymphoma in studies done in Kansas, Nebraska, Canada, and Sweden. The risk of lymphoma was highest for those who prepared and applied the chemical themselves. Dogs living where 2,4-D is used are also at higher risk for lymphoma.

Chemicals meant to kill one organism almost always affect others, including humans and pets. The fact that a product is sold on store shelves does not mean it is safe. The EPA’s registration process for pesticides has many problems that allow registration despite health effects. More information on pesticide health effects is available online at http://www.pesticideinfo.org , http://www.sfbaypsr.org/pahh.pdf , and http://www.pesticides.org .

There are safe ways to deal with unwanted weeds and insects. Good information is available in books on organic gardening and at http://www.panna.org/ and at http://www.beyondpesticides.org/alternatives/factsheets/index.htm . For insects indoors, baits and traps are much safer than sprays. Measures that deny insects access to food, water and shelter in your home discourage them from living there. As described in the companion article by Ruth Ann Ingraham, native Indiana plants are more resistant to local pests and can help reduce chemical use outdoors. Please consider using alternatives to chemical pest control.