Toxic Lawns: What You Don't Know Can Hurt You

I love to garden and I spend a lot of time on my lawn and flowers. But I never use lawn chemicals like weed-killers (also called herbicides). The risks are just too high for the perceived benefit of killing a few dandelions. People -- even some really smart people I know -- have the attitude that "they couldn't sell it is it wasn't safe." But you know what? They can and they do. 

Lax regulations by the Environmental Protection Agency (EPA), savvy marketing, and an uninformed consumer have turned the lawn business into a $25 billion a year industry for chemical companies. Current estimates of the number of American households that use lawn pesticides run as high as 82% according to Viriginia Scott Jenkins' book "The Lawn: A History of an American Obsession." And many of these chemicals are known to cause both acute (severe and sudden onset) or chronic (develops and worsens over time) health effects. 


Who's At Risk?

Pregnant women, infants and children, the elderly, and the chronically ill are at greatest risk from pesticide exposure and chemically induced immune-suppression, which can increase susceptibility to cancer. Pets and other animals are also particularly susceptible to herbicides’ effects. The following information is from the group Beyond Pesticides, a non-profit that advocates for a safer environment: 

• Children take in more pesticides relative to body weight than adults and have developing organ systems that make them more vulnerable and less able to detoxify toxins.
• The National Academy of Sciences estimates 50% of lifetime pesticide exposure occurs during the first 5 years of life.
  
• Children ages children ages 6-11 have higher levels of lawn chemicals in their blood than all other age categories. 
• A study published in the Journal of the National Cancer Institute finds home and garden pesticide use can increase the risk of childhood leukemia by almost seven times.
  
• Exposure to pesticides can increase a child’s likelihood of developing asthma.
  
• Pesticides are linked with hyperactivity, developmental delays, behavioral disorders, and motor dysfunction.
• Biomonitoring studies find that pesticides pass from mother to child through umbilical cord blood and breast milk.
• Low levels of exposure to lawn pesticide products are linked to increased rates of miscarriage, and suppression of the nervous, endocrine, and immune systems.
• Dogs exposed to herbicide-treated lawns and gardens can double their chance of developing canine lymphoma and may increase the risk of bladder cancer in certain breeds by 4-7 times.
• Of 30 commonly used lawn pesticides: 16 are toxic to birds, 24 are toxic to fish and aquatic organisms, and 11 are deadly to bees.

Most Common Weedkillers

I decided to research the two most commonly used home and garden weedkillers used in the US, glyphosate and 2,4-D. Never heard of them? Chances are you'll recognize their product names.

Glyphosate (active ingredient in Monsanto's Roundup products and various commercial formulations)

Glyphosate is the most commonly used herbicide in the world and is used to kill over 200 types of common weeds, including dandelions and poison ivy. Pure glyphosate is not highly toxic, but when mixed with other ingredients as it is in Roundup products, negative health effects have been observed (Beyond Pesticides).

Glyphosate is classified by the EPA as non-carcinogenic (not cancer-causing) and marketed as benign; however, laboratory testing has shown some evidence of carcinogenicity and other long-term problems. Glyphosate-containing products are acutely toxic to animals and humans. Symptoms include eye and skin irritation, headache, nausea, numbness, elevated blood pressure, heart palpitations, and chest pains according to the National Pesticide Information Center (NPIC). The group Beyond Pesticides reports the following chronic health effects, compiled from various research studies:

• Studies have found that people exposed to glyphosate are 2.7 times more likely to develop Non-Hodgkin’s Lymphoma (NHL). 
• In 2002 a study of Swedish men showed that glyphosate exposure was significantly associated with an increased risk of NHL, and hairy cell leukemia. 
• Further, a review of studies conducted on farmers by researchers at the NCI showed that exposure to glyphosate was associated with NHL. 
• Additionally, an agricultural Health Study (AHS) found that glyphosate had a suggested association with multiple myeloma. 
• Glyphosate and its formulated products adversely affect embryonic, placental, and umbilical cord cells, and impact fetal development. 
• Preconception exposures to glyphosate were found to moderately increase the risk for miscarriage. 
• Glyphosate use directly impacts a variety of non target animals including insects, earthworms, and fish.

2,4-D (found in Ortho Weed-B-Gon, Spectracide Weed Stop for Lawns, Scotts Weed and Feed, and many others)

2,4-D (2,4-dichlorophenoxy) is a commonly used herbicide. Developed in the 1940s during World War II, 2,4-D was widely used in the Vietnam War to destroy foliage and crops in an effort to expose the enemy by destroying their cover and depleting food sources. This herbicide remains in widespread use today to control broadleaf plants such as dandelions and clover. Different formulations vary widely in levels of toxicity, health effects, and environmental impact, leading to debate over regulations. Health effects are of particular concern due to its widespread distribution and ability to drift off-site (NPIC). 

Acute toxicity includes severe eye irritation, coughing, dizziness, loss of muscle coordination, nausea, diarrhea, and vomiting. Acute neurotoxic effects include inflamed nerve endings, lack of coordination, stiffness in arms and legs, inability to walk, fatigue, stupor, coma, and death. Although the EPA continues to maintain that there is not enough evidence to classify 2,4-D as a carcinogen, a growing body of research has begun to link it to a variety of cancers and other chronic health problems (NPIC).

• A 1986 National Cancer Institute (NCI) study found farmers in Kansas exposed to 2,4-D for twenty or more days a year had a sixfold higher risk of developing Non-Hodgkin’s Lymphoma (NHL) (Beyond Pesticides). 
• Five years later, another NCI study demonstrated that dogs were twice as likely to contract lymphoma if their owners used 2,4-D on their lawns. 
• An increased risk of bladder cancer in Scottish Terriers was found to be associated with exposure to chemically treated lawns (Beyond Pesticides).
• Several university studies done in the US have confirmed that rapid and repeated division of blood cells occurs in pesticide applicators using 2,4-D, in addition to increased activity of a tumor gene in the liver (NPIC).
• University of Minnesota study found 2,4-D mimics estrogens in breast cancer cells (NPIC).
• University of Missouri study reported a strong correlation between low sperm counts, high numbers of abnormal sperm, and atrophy of the testes with high levels of 2,4-D (NPIC). 
• Long-term animal studies of chronic exposure have shown effects on the blood, liver, and kidneys (NPIC). 
• Studies have also revealed slight chronic symptoms including a reduction in weight and changes in blood chemistry (NPIC). 
• 2,4-D is a developmental toxicant. Some observed effects are increased gestational length, skeletal abnormalities, and effects on the thyroid and gonads. (NPIC)
• Studies of Minnesota farming regions found a higher rate of birth defects among children of crop workers who conceived the children during the months when 2,4-D was sprayed (Environmental Health Perspectives). 
• 2,4-D is reported to have negative effects on the endocrine system (specifically the thyroid and gonads) and immune system (Beyond Pesticides).
• A 2004 CDC study reported permanent neuromuscular effects such as muscle twitching, weakness, and loss of tendon reflexes (Beyond Pesticides). 

Flawed Regulation

The Environmental Protection Agency (EPA) is responsible for the assessment and registration of herbicides and other chemicals. According to the EPA website, the agency evaluates health and environmental safety to ensure that when the chemicals are used according to label directions they will not harm people, non-target species, or the environment. Once registered, pesticides are periodically reviewed for safety. If new concerns arise, EPA can change or cancel their registrations, though that rarely happens. 

Critics of the EPA process note many flaws in the system including the fact that the EPA relies heavily on health data provided by manufacturers of these chemical to make their assessments, and they argue that the pesticide testing protocols are outdated. Additionally, the agency only conducts toxicity tests on individual chemicals, yet most homeowners are applying them in the mixtures found in various products. The EPA has also been criticized for failing to pursue false safety claims made by chemical companies. Another limitation is that lawn-care pesticides are not tested for their chronic health effects unless they are also licensed for food uses. The third most heavily used herbicide in the US, MCPP, has not been fully tested for chronic health effects since it is not allowed for use on foods. 


Industry Tactics

The agricultural industry maintains an army of lobbyists in Washington DC, state capitals, and countries worldwide to protect their interests. As a special interest lobbying bloc, agribusiness spends over $100 million a year lobbying Congress. In addition, many of the agrichemical industry's former executives, lawyers, and scientists serve in the government agencies that regulate their industries. 

According to the National Resource Defense Council (NRDC), critiques of scientific experiments have become integral to what is known as the “sound science” campaign, an effort by interest groups and industries to slow the pace of regulation. David Michaels, the Assistant Secretary of Labor for Occupational Safety and Health, wrote in his book “Doubt Is Their Product” that corporations have developed sophisticated strategies for “manufacturing and magnifying uncertainty.” In the eighties and nineties, the tobacco industry fended off regulations by drawing attention to questions about the science of secondhand smoke. Many companies have adopted this tactic. “Industry has learned that debating the science is much easier and more effective than debating the policy,” Michaels wrote. “In field after field, year after year, conclusions that might support regulation are always disputed. Animal data are deemed not relevant, human data not representative, and exposure data not reliable.”
  

Banned!

Some communities are banning the use of herbicides based on health concerns. More than 80 percent of the Canadian population has banned “cosmetic” herbicides used to kill dandelions, clover, and other weeds on lawns. Most major Canadian retailers including Home Depot have stopped selling herbicides and have committed to selling alternatives. Denmark, Norway, and Sweden have all banned 2,4-D. The European Union is also setting limits by banning pesticides associated with cancer and disruption of human hormones or reproduction. 

In the US, the states of New York and Connecticut banned the applications of lawn pesticides around schools and daycare centers. More than thirty-five municipalities in New Jersey have enacted bans of synthetic lawn pesticides on public property, as have Camden, Maine; Hebron, Connecticut; and Marblehead, Massachusetts.


Alternatives 

There are many organic alternatives to chemical products and landscaping practices that can help to beautify a yard. I'm no expert here...I usually just pull them out... but I've heard of success stories with vinegar and salt. Or you can just live with your weeds. Did you know that clover is an excellent source of nitrogen and helps to green your lawn? In fact, Scotts Miracle Gro company used to market a product called Clovex that helped clover grow, until consumers decided they wanted to kill it.