RODALE NEWS, EMMAUS, PA—With winter fully upon us, you may have a few unwanted guests trying to sneak inside where it's warm. This time of year is prime "migration" season for mice and rats who don't like the cold weather any more than you do. But before you try to get rid of them with one of those bait traps from the home and garden store, consider that those traps are so toxic, they'll soon be illegal. The U.S. Environmental Protection Agency (EPA) will be instituting new regulations this year, banning the residential use of certain highly toxic pesticides used for rodent control that are threatening children and pets as well as a variety of wildlife, including barn owls.
The new rules couldn't come soon enough, says Jay Feldman, executive director at the nonprofit group Beyond Pesticides. The pesticides that will soon be banned were invented in the 1970s, and as long ago as the early '80s, scientists suspected that they were threatening wildlife. "The new regulations are so logical, it's almost laughable that these things weren't more carefully managed," Feldman says. But the new guidelines leave a lot to be desired, particularly when it comes to farming, and he says that going organic could be an easy way to ditch rodents without harming people or animals.
THE DETAILS: The new EPA guidelines for rat poisons are scheduled to go into effect in June. Provided that industry influence doesn't prevent them from being fully implemented (and the industry is fighting them under the guise that controlling rodents is a public health issue), the new guidelines would focus primarily on what are called "second-generation anticoagulants," which act as blood thinners. These four chemicals, brodifacoum, bromadiolone, difenacoum, and difethialone, are currently used in a variety of home rodent-control products and considered extremely toxic. According to the American Association of Poison Control Centers, they're the second-leading cause of pesticide-related calls to poison control centers in this country. That's primarily due to the fact that they're sold as pellets and used in open-bait traps that children and dogs have easy access to. The new rules would ban all four of those chemicals in consumer products sold at grocery, drug, and hardware stores, and require that all pellet baits that use alternative chemicals be sold in tamper-resistant containers. The rules would also put severe restrictions on how professional exterminators can use rodent baits in homes.
An even bigger problem is the threat these toxic chemicals pose to wildlife, says Feldman. There is more use of baits in agriculture than in homes, he says, and it becomes difficult to prevent wildlife poisonings if the material is used. Unlike the first-generation rodenticides that were invented back in the 1940s, these newer poisons are effective with a single feeding. But they still can take up to five days to kill a rodent; so as the animals stagger around after eating the rodenticide, other predators, such as owls and bald eagles, eat them and ingest these toxic pesticides. A 2009 study in Canada found that 75 percent of barn owls living in British Columbia and the Yukon Territory had rodenticide chemicals building up in their livers. The chemicals don't necessarily kill the owls outright, but they can interfere with blood clotting, turning small cuts into life-threatening ailments, or affect the birds' ability to fly, causing them to get hit by cars.
Other studies have found these dangerous chemicals building up in the bodies of herbivorous animals like squirrels and deer. Scientists aren't sure why they're building up in herbivores, but the evidence suggests that the chemicals are extremely persistent in the environment and do damage far beyond the rats and mice they're intended to kill.