Pesticides: What You Don’t Know Can Hurt You

Pesticides: What You Don’t Know Can Hurt You

If someone tried to sell you wallpaper for your living room that had been shown to cause cancer, disrupt the growth and development of children, and sicken pets, you’d no doubt laugh in astonishment — and be horrified that such a product had made it to market. In fact, you’d never allow any product in your home that had such demonstrated adverse health effects, and you likely wouldn’t enter the homes of people who did.

And yet despite your vigilance indoors, you might be one of millions of American homeowners who routinely buy and use lawn and garden pesticides — which means you are introducing chemicals that can inflict severe illness into the space where you and your family spend much of your time. If so, consider this: research on 30 commonly used lawn pesticides reveals that 19 might cause cancer, 13 are linked to birth defects, 21 are linked to reproductive effects, 15 cause neurotoxicity, 26 may damage the liver and kidneys, 27 irritate skin and other tissues, and 11 have the potential to disrupt the endocrine (or hormone) system.

The popularity of lawn and garden chemicals is indisputable: an estimated 78 million U.S. households use these pesticides — including an annual 90 million pounds of herbicides alone — compared to only 5 million households that report using only organic lawn care practices. In fact, suburban lawns and gardens receive more pesticide applications per acre (roughly 3 to10 pounds) than do agricultural crops (about 3 pounds per acre on average).

The allure of pesticides lies no doubt in the desire for pristine, weed-free lawns and bug-free plants, but organic methods have been shown to work as well, if not better, than pesticides — without the threats to your health. Here are some reasons to rethink outdoor pesticide use.

“Legal” does not mean “safe”
Consumers have a false perception that products approved for use by the government are necessarily safe. While it’s true that all pesticides must be registered with the Environmental Protection Agency, a registration is neither an endorsement nor a guarantee of safety. Moreover, it does not ensure that the pesticide has been tested thoroughly for environmental and human health effects. Registration simply means the EPA has determined that a pesticide, when used according to label instructions, “can be used with a reasonable certainty of no harm to human health and without posing unreasonable risks to the environment.”

That sounds good, until you consider this: the health data EPA reviews when deciding whether to register a pesticide are provided by the pesticide’s manufacturer; the law does not require EPA to evaluate independent studies by disinterested researchers. What’s more, the list of tests EPA requires manufacturers to perform on pesticides for registration has not been updated to reflect new science on the human immune and endocrine system, and does not include tests on several neurological effects.

Finally, EPA only reviews the safety of individual active ingredients — it does not consider the safety of the actual pesticide formulations sold on the shelf, which include both active ingredients (those that kill the targeted pest) and inert ingredients (those that help the chemical stick to the plant, known as surfactants, or that perform some other function). This gives consumers a false sense of security, notes Jay Feldman, executive director of the Washington, D.C.-based organization Beyond Pesticides, because the data submitted to EPA does not account for the toxicological interplay between actives and inerts.

“The registration system has deficiencies because the agency doesn’t look at chemical mixtures,” Feldman says. “As we eat, breathe, play, and garden outside, we’re not exposed to individual chemicals but to mixtures of chemicals. And researchers are finding that the various chemicals in mixtures do have a synergistic effect.”
In other words, he notes, “mixtures can be more potent than the individual chemicals.” What’s more, analyses of certain inert ingredients — which are considered confidential business information and do not have to be listed on the label — show they are often more toxic than the active ingredients themselves.

Pesticide residues migrate
Homeowners, especially those who use lawn care services, may also assume that they won’t be exposed to pesticides in their yards because the chemicals will dissipate once they’re applied. This isn’t true. Pesticides present a risk through direct application, because they can drift from the target site into homes through open windows and ventilations systems., Once they form a residue on grass and plants, pesticides can be inhaled (if they volatize in the heat) or absorbed through the skin (if touched). Young children, who are more vulnerable to the toxic effects of chemicals because they eat more food, drink more liquids and breathe more air in proportion to their size than adults do, risk additional exposure from ingestion if they touch treated plants and put their hands in their mouths.

Furthermore, residues can rinse off in the rain and contaminate surface and groundwater or brush off onto the coats of cats and dogs, who then enter the home and deposit them on furniture and other surfaces. And pets don’t just transfer pesticides; they can be severely sickened by them. Studies have shown that dogs exposed to herbicides have increased rates of lymphoma and bladder cancer. And pesticides can be toxic to wildlife, such as birds, fish, and bees, as well as to insects and soil microorganisms that are essential to keeping lawns healthy.

The national non-profit, Beyond Pesticides, has compiled lists of the environmental and health effects associated with the most commonly used lawn and garden pesticides. Here’s a glance at five of the most popular:

2,4-D: Despite more than 60 years of commercial availability, there remain significant data gaps on the health and environmental effects of this herbicide. Questions linger about its long-term impacts on human health and water quality, and studies have shown 2,4-D to demonstrate such adverse effects in animals as cancer, damage to the reproductive and hormone systems, kidneys, liver and skin, and birth defects.

Glyphosate: A highly persistent herbicide that lingers on crops for months, glyphosate is found in products that are acutely toxic to animals, including humans. Symptoms include eye and skin irritation, headache, nausea, numbness, elevated blood pressure, and heart palpitations. The surfactant used in Roundup, a common glyphosate product, has been shown to be more acutely toxic than glyphosate itself, and the combination of the two is still more toxic. Studies on farmers exposed to glyphosate herbicides have shown an increase risk of miscarriages, premature birth, and non-Hodgkin’s lymphoma.

MCPP (Mecoprop): An herbicide found in many household weed killers and “weed-and-feed”-type lawn fertilizers, mecoprop has been shown to cause reproductive effects, kidney and liver damage, birth defects, and skin irritation. It is toxic to birds and aquatic organisms and has been detected in groundwater.

Pendimethalin: A pre-emergent herbicide used to prevent crabgrass from germinating, pendimethalin must be “watered in” so it reaches seeds deep in the soil. It is highly toxic to fish and other aquatic organisms and is associated in animals with reproductive effects, hormone disruption, kidney and liver damage, and skin irritation.

Dicamba: Used alongside Agent Orange in Vietnam, dicamba is a lawn and garden herbicide that is extremely mobile in soil and has caused concern over its potential to contaminate groundwater. In animals, it has been linked to reproductive effects, kidney and liver damage, neurotoxicity, birth defects, and skin irritation.

-Lucy Ament
Summer 2010

Click Pesticides: What You Don’t Know Can Hurt You for a downloadable pdf version of this article.

This entry was posted in Healthy Living, Lawn and Garden, Pest Patrol and tagged . Bookmark the permalink.