Protecting Children from Toxins
Toxic pesticides are more readily absored by the plastic used to make toys
While video cameras rolled at Rutgers University in New Jersey, a group of toddlers went about their usual business--snuggling noses into soft, plush stuffed animals, moving from toy to toy, sucking on their fingers, sucking on the toys. Later, as researchers reviewed the tapes, they counted each time a child touched a toy or moved a hand to a mouth.
Given the amount of news just before Christmas season about the potential hazards of certain soft plastics used in some toys, you might expect that the researchers were checking out how much those plastics end up in kids´ mouths. You would be partially right. But this study was about children´s exposure to toxic substances parents themselves unwittingly can put on their own children´s toys and elsewhere inside homes.
Along with calculating childhood behavior patterns, the researchers had been analyzing the movement of roach and flea sprays commonly used in American homes. According to team leader Paul J. Lioy of the Environmental and Occupational Health Sciences Institute located at Rutgers, the scientists were surprised by their own results. "We expected the pesticides would volatilize and move outdoors or just dilute," Lioy says. But instead the team discovered that plastic and plush toys attracted the pesticides; the poisons were evaporating off of floors, carpets and drapes, latching onto the toys and staying there for weeks after rooms had been sprayed.
The study, published last year, raises concerns that children may be at much greater risk from routine pesticide spraying than anyone had previously estimated, according to epidemiologist Devra Davis of the nonprofit World Resources Institute in Washington, D.C., and former science advisor to the U.S. Department of Health and Human Services. Since young children spend a lot of time putting things in their mouths, contaminated toys are likely to give them much higher doses of poison than adults would get in the same environment. "And of course, the younger the child, the greater the risk that exposure to pesticides could cause health problems," says Davis. Pesticides also can be absorbed through the skin.
Generally, exterminators and pesticide labels tell people to keep children and pets away from wet bug spray. Dried spray residues have not been considered a problem. But the researchers at the health-sciences institute discovered that the semivolatile dried pesticides tend to leap around the room, moving from one object to the next.
Scientists have long known that this phenomenon takes place in the outdoor environment. It´s called the grasshopper effect. Pesticides sprayed on southern soils volatilize, or evaporate, move northward and accumulate in cool places such as Lake Superior, where they pose a potential threat to a variety of wildlife species. Lioy´s team suspected that semivolatile pesticides might behave in much the same way indoors, and their suspicions turned out to be correct. "It´s like the grasshopper effect in your house," Lioy says. "But instead of going from Mexico to Canada, the chemicals move from the rug to the toy."
The team used a professional exterminator to treat two university apartments, using a fine mist of pesticide sprayed across carpets and floors. That´s the same technique exterminators normally use to treat homes for roaches or fleas. The toys weren´t put into the apartments until the rooms were aired out and the spray had dried.
When the scientists measured the amount of pesticide that collected on various objects, they found that plastics and foam attracted the chemicals more than anything else. "Toys are made of materials that have an affinity or ability to capture pesticides in greater concentration than other materials, such as metal or wood," Lioy says. "The polyfoam acts like a sponge for the pesticides. The plastic may electrostatically attract the vapor." And the plastics and foam continued to accumulate the pesticides up to two weeks after the apartments were sprayed.
According to Lioy, anything made of plastic or foam would have the same ability to attract pesticides. Toys are of special concern because children spend so much time handling them. He adds that foam pillows may also be a source of pesticide exposure, but pillows weren´t tested in this study.
Davis thinks this study is especially important because the bug spray tested is one of the most widely used pesticides in the nation. Chlorpyrifos, which is also known by the trade name Dursban, is used to kill fleas, roaches, termites and any number of garden pests. The chemical is found in flea collars and dips, and in common household bug sprays such as Raid. The manufacturer, Dow AgroSciences, estimates that chlorpyrifos is sprayed in and around an estimated 20 million American homes every year.
Chlorpyrifos is an organophosphate, a class of pesticide that was originally developed as a nerve-gas agent for chemical warfare. Organophosphates work by paralyzing muscles, and in large amounts they can kill humans and other species in the same way that they kill bugs. In the winter of 1995, for example, biologists in Argentina discovered thousands of Swainson´s hawk carcasses near fields that had been sprayed with the organophosphate monocrotophos. Farmers had been using that pesticide to kill grasshoppers. Biologists say as many as 20,000 Swainson´s hawks may have died from the poisoning.
No one is certain what the health effects of long-term, low-level exposure to organophosphates might be. Dow AgroSciences researchers say their tests show that low-level exposures pose no threat. But other scientists disagree. Some studies have suggested that these pesticides may contribute to health effects ranging from immunological problems to birth defects, and according to the Environmental Protection Agency (EPA) more than 200 people have filed complaints alleging health problems from exposure to chlorpyrifos in their homes.
Those complaints include headache, dizziness, respiratory distress, abdominal cramps, nausea, vomiting, diarrhea, blurred vision, increased sweating, confusion and muscular weakness. Other studies have suggested a link between exposure to flea sprays and leukemia, brain tumors and other childhood cancers.
The EPA now urges that whenever this pesticide is used, it should be applied only in a fine stream in cracks and crevices and not sprayed in a mist over floors. Lioy agrees with that advice and also recommends that parents keep toys stored whenever children aren´t actually playing with them for at least a week after pesticides are used in the home.
And Davis adds that the safest course is to find alternatives to pesticides. Other ways to combat flea infestations, for example, include washing pets and frequent vacuuming of floors, carpets and upholstered furniture. "We´ve got to get smarter about using pesticides in the environments of our children," says Davis. "We can´t eliminate all pesticide use, but we´ve got to start using fewer pesticides."
Free-lance writer Vicki Monks last wrote about the effects of toxics on the young in "Children at Risk," National Wildlife, June/July 1997.