Steve Tvedten - Interviewed on safe lawn care
Spread with care
By REID MAGNEY | Of the Tribune staff
A thick, weed-free lawn is the vision of outdoor perfection for many Americans.
To get that perfect emerald turf carpet, Americans will spend lots of green - more than $4 billion annually on lawn care products. And to wage war on dandelions and crabgrass, 26 million households hired lawn care services in 2000.
But is there a greater cost?
Studies by researchers in Wisconsin and Minnesota are raising questions about health and environmental problems caused by spraying and spreading chemical pesticides and fertilizers.
Government is taking notice. The U.S. Environmental Protection Agency has recently banned home use of some common pesticides like Dursban and Diazanon, though existing stocks are still available in some stores.
Canada's highest court has upheld the right of cities to ban the use of pesticides and fertilizers on public and private land.
"We just don't need it," said Barbara Frank of La Crosse, who chairs the Sierra Club's Midwest Regional Conservation Committee. "It's better to live with a few weeds in a more natural lawn than to run the risk from pesticide exposure."
"I'm a breast cancer survivor, and I get nervous about being exposed to pesticides and herbicides," Frank said.
Joe Bilskemper of Onalaska, owner of Lawn Care Specialists Inc., said proper application is critical. He said the pesticides and fertilizers used by his lawn care company and others are the same products sold retail to the public.
"People are better off hiring a professional" than running the risk of applying the products themselves," Bilskemper said.
"There's very little risk when products are applied according to the label directions."
But professor Warren Porter, chairman of the Department of Zoology at the University of Wisconsin, said there is growing evidence that lawn chemical mixtures can be dangerous to human and animal health, even when used according to label directions.
Porter's previous studies have shown that a common mix of agricultural insecticide, herbicide and fertilizer found in drinking water altered the thyroid hormones of young mice, changing their aggressiveness and suppressing their immune systems.
Porter said he will publish a study in July about "one of the most common lawn chemical mixes," that looks at biological effects at ultra-low doses. Porter said he can't identify the mixture until after the study is published but noted it is one in products commonly applied by both homeowners and professionals in this part of the country.
"The key thing that people need to understand is why it is all these pesticides molecules are biologically active," Porter said. "They have a way to get through the cell wall, or any waxy surface - first your skin and then the cells that make up your body."
Once inside the body, Porter said, "the opportunities for effects are really enormous."
"If you look at the Materials Safety Data Sheets for these lawn herbicides - and this is what got me looking at lawn chemicals - they are rated as either immediate or long-term, or both, health hazards," Porter said.
A 1996 study done by the EPA and the University of Minnesota has shown that children of pesticide applicators have significantly higher rates of birth defects than the general population. The study by Dr. Vincent Garry, professor and director of the University of Minnesota Laboratory of Environmental Medicine and Pathology, looked at more than 200,000 children born in Minnesota between 1989 and 1992.
Porter said the study found a significantly higher birth-defect rate in regions of high pesticide usage.
The lawn care industry admits that pesticide use carries a risk.
"Homeowners should be aware that the use of pesticides does pose some risk, and their use cannot be made completely safe," according to an information pamphlet supplied to consumers by the Professional Lawn Care Association of America. "Improper or inappropriate use of pesticides and other lawn care products by either the homeowner or the lawn care professional can increase the level of exposure, which in turn increases the level of risk posed to human health and the environment."
Mohamed B. Abou-Donia, a professor of pharmacology and cancer biology at Duke University Medical Center, said new research has shown pesticides are even more harmful when they are used in combination with other chemicals, like DEET, a mosquito repellent. The combination "impedes the body's ability to get rid of the chemicals," he said.
"If you have to use it, use the least amount that you can get by with," said Abou-Donia, who recently presented papers on pesticides at a Seattle conference. "This is the first rule. The second rule is try not to combine it with other chemicals."
Homeowners can choose to avoid chemicals on their yards, but what about the neighbors' yards?
Joyce Arthur of La Crosse is one of 18 La Crosse County families that asked to be on the state's Landscape Application Registry, so she will be notified at least 12 hours before a neighbor's lawn gets sprayed.
"I wanted to know when they would be spraying so I could stay in the house and not breathe the pesticides," Arthur said.
But staying inside is no guarantee against lawn pesticide exposure, according to a 2001 study by the EPA and Battelle Memorial Institute. The study measured levels of the herbicide 2,4-D in 13 homes before and after lawn application. The herbicide, carried in by pets or homeowners, was detected inside in all the homes.
The study estimated post-application pesticide exposures to children at 10 times higher than pre-application exposures. That's a concern, Porter said, because fetuses and children do not have defensive enzymes that adults develop to help detoxify the body.
Janet Horihan of West Salem also is on the notification registry so she can close up her house before her neighbors' houses get sprayed. "I have respiratory problems. My eyes and throat burn," she said. "I have two children at home. When they were younger, one had to go to the hospital regularly every time they sprayed."
Consumers should ask tough questions about any pesticide that a lawn service wants to spray on their property, said Stephen Tvedten, a nationally known expert on integrated pest management and the author of the book "The Bug Stops Here!"
Integrated Pest Management - IPM for short - can have different definitions. Tom Delaney, executive vice president of the Professional Lawn Care Association of America, said IPM practices can include proper mowing, regular watering, aeration, seeding and pH balancing.
To Tvedten, IPM is finding least-poisonous methods of controlling bugs and weeds. "Everything is common sense. My mother taught me IPM when I was about 4 years old in Marshfield, Wis. She said, 'Stephen, shut the door. You're letting in flies.'"
Pesticides also make for an unhealthy lawn, Tvedten said. "Because of all the synthetic pesticide poisons and fertilizers, our top layer of soil is virtually dead," he said. "Soil must be alive, teaming with microorganisms or the lawn and/or plants will not be healthy.
If you feel you must kill dandelions and other weeds, there are many safer and inexpensive alternatives to chemicals, Tvedten said.
"Safe alternatives actually work far better, are safer, and more economical than the poisons to begin with," Tvedten said. "For every pest that you can name, I can give you a handful, or more, of alternatives on how to address the issue."
Tvedten suggests spraying weeds in cement cracks and along fences with vinegar, or even undiluted Coca-Cola. "Always do this on a hot, sunny day, as this will help kill the weeds," he said.
"There are many, many, many solutions if you just think. You have a brain that is 200,000 times bigger than your insect pests. If you use it, you'll win. If you use pesticides, you'll lose."
To get a free copy of Stephen Tvedten's book, "The Bug Stops Here!" go to The Best Control
Original Article: http://www.lacrossetribune.com/rednews/2002/05/12/build/news/003spread.php
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