Killer Bug Killers

Flea collars and no-pest strips may be toxic to kids as well as insects.

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.

    Many other studies have connected home pesticide use and childhood cancers as well. Notably, in 1987 researchers at the University of Southern California demonstrated that childhood exposure to home pesticides contributes to childhood leukemia, and a 1989 USC study concluded that home pesticide exposure was "the most consistent finding" distinguishing children in the study' s sample who had leukemia from those free of the disease.

    Officials with the Missouri Department of Health studied children with cancer and found that those who had brain cancer also had significantly more exposure to pet flea collars, no-pest strips, garden pesticides, and Kwell shampoo, a pesticide used to treat lice.

    But if you throw away your flea collars and chemical yard pesticides, are you condemned to fleabites and a garden overrun with bugs and weeds? Not at all.

  • Fleas Instead of chemical foggers or flea collars, try a flea collar made with the medicinal herb pennyroyal. Wash pet bedding and vacuum frequently. Bathe your pet often; comb its fur with a flea comb and dump captured fleas in soapy water. At night, set a gooseneck lamp on the floor above a bowl of soapy water. The light attracts fleas, and they jump into the water and drown.

  • Flies and mosquitoes Install or repair screens. Eliminate standing water (for example, birdbaths). Seal garbage containers. Cover or seal foods. Hang flypaper.

  • Cockroaches Roaches love to burrow in cracks and holes. Caulk all openings in floors, walls, cabinets, etc. Use roach motels, and dust roach-infested areas with boric acid powder.

  • Ants Get ant bait, little metal or plastic containers filled with poison-laced jelly. The ants carry it back to their nest, and the entire nest dies. The poison is bad news for the ants, but won' t harm you: It' s impregnated in the jelly and does not blanket your home the way chemical sprays do.

  • Patio bugs Try burning citronella candles. Like pennyroyal, citronella oil repels insects.

  • Lawn and garden pests Plants native to your area tend to resist local pests better than imported outsiders. Ask garden centers about pest-resistant plants. Organic gardening books and magazines offer other good ideas. For instance, they suggest you pick bugs off plants by hand. Or blast them with a hose. Or spray leaves with soapy water. For even more anti-pest punch, try nonpetrochemical pesticides, available at nurseries and at home supply and hardware stores. Their active ingredients are aromatic oils that plants such as citronella and pennyroyal developed to defend themselves against pests. Unlike petrochemical pesticides, these potent natural repellents have never been linked to cancer. Organic Solutions of San Antonio, Texas, offers a line of bug killers based on a combination of chrysanthemum extract (pyrethrin), an extract of the Kenyan ocotea tree (piperonyl butoxide), and diatomaceous earth (soil containing the fossilized bodies of prehistoric single-cell plants called diatoms, which slice into the bugs, dehydrating them). The Ringer Corp. of Minneapolis markets Safer, a line of nonpetrochemical pesticides that attack an insect' s nervous system with pyrethrin and an extract of the Indian neem tree, using a soaplike chemical to dehydrate bugs. Ringer also produces a soap-based weed killer.

    Michael Castleman is the best-selling author of Nature's Cures, published by Rodale Press.