04/21/2011 10:53 pm ET | Updated Jun 21, 2011

The Lawn Chemical Ritual

Ah, spring. The robins are back, the cherry trees are in bloom, and the armies of lawn chemical trucks are prowling the neighborhood, looking for business. It's that time of year again.

I was startled from my work this afternoon by a knock on the door: The driver of a lawn care truck had pulled up in front of our house, and now, looking askance at our decidedly shabby-looking lawn, he gave me The Look. What you need, he said, is a two-year contract for pesticide treatments that would "really take care of the weeds."

To be fair, his timing could not have been worse. I had just finished two years of research into the health and environmental effects of synthetic chemicals, and here he was trying to convince me to spread pesticides on the lawn where my kids and dogs play every afternoon. The exchange did not last long.

I wondered: would the lawn care guy, who was just doing his job, be interested in the research I had discovered? Would he want to know of a study that showed a three-fold increase in lung cancer in lawn care workers who used a common chemical known as 2,4-D, or another that found a higher rate of birth defects among the children of chemical appliers?

Probably not. Business is business, and his business is a big. American spend roughly $40 billion a year on lawn care. In 1999, more than two-thirds of America's home lawns were being treated with chemical fertilizer or pesticides -- 14 million of them through a professional lawn care company. A year later, the federal General Accounting Office reported that Americans were spraying 67 million pounds of synthetic chemicals on their lawns every year, and that annual sales of lawn care pesticides had grown to $700 million. Lawn care companies were doing an additional $1.5 billion in business.

But at what cost? 2,4-D, for example, was once used as a constituent of Agent Orange. Now in wide domestic use, 2,4-D has properties considered very attractive by lawn chemical companies: it kills broad-leaf plants, like dandelions and clover, without killing grass. Today, annual sales of 2,4-D have surpassed $300 million worldwide. Since it does not require a license to buy, or to use, 2,4-D can be found in many "weed and feed" products like Scotts Green Sweep, Ortho Weed B Gon, Salvo, Weedone, and Spectracide.

Because it is designed to mimic a plant's natural growth hormone, 2,4-D causes such rapid cell growth that a plant's normal transport systems become destroyed by abnormally fast tissue growth. The stems of plants treated with 2,4-D tend to become grotesquely twisted; the roots become swollen; the leaves turned yellow and die. Plants quickly starve to death.
Given its effects on the cell growth in plants, it should perhaps not be surprising that 2,4-D has also been shown to disrupt human hormones. The National Institute of Health Sciences lists 2,4-D as a suspected endocrine disruptor, and several studies point to its possible contribution to genetic mutations and problems with reproductive health. Although the EPA continues to list 2,4-D as lacking enough evidence to be classed as a carcinogen, a growing body of research has begun to link it to a variety of cancers, including non-Hodgkin's lymphoma. A 1986 National Cancer Institute study found that farmers in Kansas exposed to 2,4-D for 20 or more days a year had a six-fold higher risk for developing non-Hodgkins lymphoma.
Five years later, another National Cancer Institute study showed that dogs were twice as likely to contract lymphoma if their owners used 2,4-D on their lawns.

Like flame retardants, and countless other compounds, 2,4-D also tends to accumulate inside people's homes, even days after the lawn outside has been sprayed. One study found 2,4-D present in the indoor dust of 63 percent of sampled homes; another showed levels of 2,4-D in indoor air and on indoor surfaces like floors and tables increased after lawn applications. Exposure levels for children were ten times higher than before the lawns were treated, an indication, among other things, of just how easily the chemical is tracked inside on the little feet of dogs, cats, and children.

2,4-D, of course, is just one of scores of pesticides in broad use today. Dr. David Pimentel, a professor of entomology at Cornell, has written that 110,000 people suffer from adverse health effects from pesticides each year, and that 10,000 cases of cancer may be attributable to pesticide exposure.

And it's not just our health that suffers from our cultural obsession with lawn chemicals; our environment suffers too. And not just from herbicides. Synthetic fertilizers, which are as much part of a landscaping contract as the weedkillers, accumulate in streams and rivers after heavy rains, and wash downstream into lakes and bays. Where I live, in Maryland, the Chesapeake Bay suffers catastrophic "dead zones" resulting from the excessive nutrients running off suburban lawns (and chicken farms -- but that's a topic for another day.) When you consider that there are roughly 50 million square acres of tended grass in the United States -- a patch of lawn the size of Nebraska -- you get a sense of the volume of chemicals we're talking about. Chemicals that are absorbed into our drinking water, into our wildlife, into our bodies.