Want to protect your kids from cancer? Then ditch your pet's flea collar. Toss the weed and insect killers. Cap the bug sprays. And take down the no-pest strips.
More than 70 million American households use pesticides each year on lawns, gardens, patios, and pets. But evidence is mounting that exposure to household pesticides raises children's cancer risk. Consider the following Denver study:
Using the Colorado Central Cancer Registry and the records of Denver-area hospitals, scientists Jack Leiss and David Savitz of the University of North Carolina identified 252 children in the Denver region who developed cancer between 1976 and 1983 before the age of 14. Next, using local phone listings, they found 222 cancer-free children who had lived in the area during the same period and were similar to the cancer kids in every other way -- age, sex, and neighborhood.
The researchers interviewed the parents of all 474 children, asking a number of questions:
Have you ever had to leave your home for a few hours while exterminators treated it?
Have you ever used insecticides or herbicides on your lawn or garden?
Have you ever hung no-pest strips in and around your home?
The study found a strong association between garden-pesticide exposure and soft-tissue sarcomas (cancer of the muscles, abdomen, heart, nervous system, and blood vessels). Compared with the cancer-free group, the children with soft-tissue sarcomas were four times more likely to have been exposed to lawn and garden pesticides.
In addition, children who had leukemia were twice as likely to have been exposed to no-pest strips. Also significant, exposure to no-pest strips and home extermination were both linked to incidence of brain tumors and lymphomas (cancer of the lymph nodes).
This study is scary, but in epidemiology no single study, no matter how apparently convincing, ever makes a case. Although the numbers seem large, only about half of the 252 kids with cancers had been exposed to pesticides. Still, this study represents just one thread in a fairly tight fabric linking home pesticide use to cancer. The herbicide most likely to have been applied was 2,4-D, one of the ingredients in Agent Orange, the defoliant used widely in Southeast Asia during the Vietnam War and linked in other studies to soft-tissue sarcomas. The most common insecticides were carbaryl and Diazinon, both associated with cancer in other studies. And the insecticide in no-pest strips, dichlorvos, has also been linked to cancer.