Products that easily control and kill weeds in crops, lawns, gardens and flower beds are a boon to gardeners and farmers. For many, these herbicides have dispatched to distant memory the tedious, backbreaking chore of pulling weeds from in and around plants, but we are all paying the price. As these weed killers find their way into our drinking water or our bloodstreams, depending on the nature of exposure, they have the potential to wreak havoc not only on the health of human beings but on that of all kinds of creatures.
The sixth most commonly used herbicide in the United States, 2,4-dichlorophenoxyacetic acid, or 2,4-D, is produced and distributed by many companies. According to Beyond Pesticides.org, 2,4-D has been linked to cancer, kidney and liver damage, reproductive toxicity and endocrine disruption. Its salt form is highly toxic when it gets in your eyes. Breathing it in causes coughing, dizziness and impaired muscle coordination. Ingesting the salt causes nausea, diarrhea and possible liver and kidney damage. Through these channels, 2,4-D also damages the nervous system. Effects include fatigue, inflamed nerves, arm and leg stiffness, lost coordination, inability to walk, coma and even death. Despite the Environmental Protection Agency's position that 2,4-D is not carcinogenic, a link between 2,4-D and non-Hodgkin's lymphoma has been established in studies conducted in the United States and Canada as well as several European countries. 2,4-D has also been linked to canine malignant lymphoma in dogs whose owners use the chemical on their lawns. In 1996 a study of children of pesticide appliers in Minnesota found to them to have a higher rate of birth abnormalities when compared with the general population. This trend to birth defects was found in birds as well. Many 2,4-D products also contain dioxins, which are very carcinogenic. Dioxins also reduce fertility, alter hormones, and cause miscarriage and birth defects.
Glyphosate, a general herbicide sprayed on food and nonfood plants, is used in 90 countries and on more than 150 crops, according to a report published by the U.S. Geological Survey. It is marketed under many names, including Roundup and Touchdown, for use on broadleaf weeds, soybeans, grasses, corn and roadsides. The report also states that in a test of 154 water sources in nine states, glyphosate was found in 36 percent of the samples. Use of this chemical has increased since crops such as soybeans and corn were genetically engineered to be resistant to Roundup. Now farmers need not be concerned when the mist from Roundup coats their food crops, but consumers should be very concerned. As studies are mounted and data reported, we are learning that glyphosate is not as safe as its producers claim. A Swedish study published in the journal Cancer reported a connection between non-Hodgkin's lymphoma and glyphosate use. An Ontario study of farmers found exposure to glyphosate was associated with a high rate of miscarriages.
Until recently studies have looked at the effects of glyphosate, the "active" ingredient in Roundup, while ignoring an "inert" ingredient, a surfactant called polyethoxylated tallowmine, or POEA. However, a new study published in Chemical Research in Toxicology 2009 demonstrated that POEA is even more toxic than glyphosate in its effects on cells in embryos, placentas and umbilical cords. So this seemingly inert ingredient, when used in combination with the active ingredient, greatly increases the toxic effects of the weedkiller.
- Beyond Pesticides: ChemicalWATCH Factsheet: 2,4-D
- USGS Toxic Substances Hydrology Program: Glyphosate Herbicide Found in Many Midwestern Streams, Antibiotics Not Common
- The Ecologist: Roundup Weedkiller
- Environmental Health News: Weed Killer Kills Human Cells. Study Intensifies Over 'Inert' Ingredients