Toxic gardens?

Concerns raised on health risks of green grass

By Francesca Lyman

Sept. 18, 2002 —  It's one of America's top pastimes — a great source of fresh air and exercise, not to mention stress relief. Gardening may not be so healthy, however, for the three-quarters of households that use lawn and garden chemicals. Experts explain the risks and suggest some greener tactics to start using this fall.

A GROWING NUMBER of communities, physicians and medical researchers are concerned that the overly liberal use of insecticides, herbicides and other chemicals on home lawns and gardens may be hazardous to human health.

U.S. lawns and gardens use 70 million to 75 million pounds of pest-killing ingredients annually, according to a recent issue of Environmental Health Perspectives. These substances, some of which include potential carcinogens and hormone disrupters, may present hazards to people who apply them and may leach into groundwater, reports the journal, published by the National Institute of Environmental Health Sciences.

Children, who may be exposed by rolling around in the grass, for instance, are especially vulnerable since they are still developing, and they absorb more of the chemicals into their bodies, pound for pound, than adults, say researchers.

"Exposures to toxic chemicals in the early years of life can increase risk of learning disabilities, behavioral problems and probably cancer and other chronic diseases in childhood and in adult life as well," says Dr. Philip Landrigan, director of the Children's Center for Health and the Environment at Mount Sinai Hospital in New York.

A National Cancer Institute study found that children whose parents used store-bought home and garden pesticides are up to seven times more likely to develop childhood leukemia.

Studies have also linked pesticide exposure to breast and prostate cancer, Parkinson's disease and immune system disorders.


The pesticide industry disputes some of these claims. "Pesticides have to be toxic to work at all, but they are not toxic to people at the levels to which people are now exposed," says Allen James, president of the Responsible Industry for a Sound Environment, or RISE, a trade association representing manufacturers, formulators and distributors of pesticide products.

Plus, James adds, these chemical are used to protect children from other health threats: "Pesticides are used for very good reasons, to curb rats and cockroaches and other pests people are not able to eradicate in other ways."

Critics complain that the Environmental Protection Agency has been too slow in screening hazardous chemicals that may cause cancer or disrupt hormones. "It took 30 years of people getting sick to get EPA to phase out some of these chemicals, but all of the most common (ones) still on the market still have all sorts of adverse health effects," says Kagan Owen of the nonprofit group Beyond Pesticides. "We're taking risks with our health and our children's health to fight crabgrass and clover. We have to ask: Are those risks worth that benefit?"

The EPA is under mandate by Congress to re-evaluate the safety of a long list of older pesticides, a process that is far from complete, says Owen.

Just as the EPA has begun re-evaluating the older but still widely used weedkiller 2,4-D, a new study in the latest edition of Environmental Health Perspectives has raised new questions about it. Researchers at the University of Wisconsin and the University of Valparaiso in Chile tested the effects of a common product containing 2,4,-D by adding it to the drinking water of laboratory mice; they found a 20 percent increase in failed pregnancies, even at doses much lower than that allowed in U.S. drinking water.


A growing number of people are turning to natural methods out of concern for pesticides' unintended side effects, notes Phillip Dickey, staff scientist with the Washington Toxics Coalition.

And now is the ideal time to start implementing greener tactics, experts say. Fall is the best time to fertilize your lawn and garden plants. Taking time to do this will strengthen their roots for the cold months ahead.

"If you strengthen your lawn, it will make it through the stress of winter, and you will have less need to go after pests later," says Gwen Stahnke, cooperative extension turf grass specialist for Washington State University in Puyallup, Wash.

Stahnke advocates learning about your lawn, even doing a soil test if necessary, and if a fertilizer is needed, using "slow release" products, so named because they release nitrogen and other nutrients over time.

"Such products," Dickey explains, "promote slow, steady turf growth, while reducing the possibility that excess nutrients will run off and contaminate surface water."

Other "green" approaches include:
--Creating a healthy garden to stop pest problems before they start.
--Identifying pests before you spray, stomp or squash. That "pest" might be a beneficial insect.
--Give nature a chance to work rather than trying to eliminate pests at the first sign of damage.
--Use the least toxic pest controls available, such as traps or barriers.
--And for lawns, mow high and often; leave grass clippings; fertilize with a natural, organic or slow-release fertilizer; water deeply but infrequently; and improve poor lawns with aeration and overseeding.


But just how dangerous are most pesticides to use? That depends on exposure and at what level, says Jay Ellenberger, an official in the EPA's Office of Pesticide Programs. "If people are reading the labels and following directions — whether they should wear eyegear or special clothing — they will be minimizing their risks to themselves to a level we think is acceptable," he says.

However, Dickey points to a recent University of Washington study that tested children living in two Seattle metropolitan area communities for exposure to pesticides by measuring urinary metabolites and found a remarkable 97 percent exposed.

Pesticide industry representatives counter that exposures to chemicals don't necessarily mean they're harmful. "We're exposed to thousands of chemicals throughout our environment, and many of them can be detected in our bodies without their doing damage," James says.

Since 1999, Seattle has reduced its use of pesticides by at least a third, partly because of evidence that the chemicals may be harming the state's vulnerable salmon populations, says Phil Renfrow of the city's parks and recreation department.

But homeowners' overuse of pesticides by far offsets the city's reductions, Renfrow adds. "All you have to do is go down to Home Depot to see products flying off the shelves, bought by people who have little clue about the hazards contained in those cans."


Francesca Lyman is an environmental and travel journalist and author of "Inside the Dzanga-Sangha Rain Forest" (Workman, 1998).


Copyright material is distributed without profit or payment for research and educational purposes only, in accordance with Title 17 U.S.C. section 107. Reference: