In the next few weeks the USDA will decide whether or not to allow corn and soybeans genetically modified to resist the effects of the weed killer 2-4-D (2,4-Dichlorophenoxyacetic acid). The makers (Dow Chemicals) claim the new strains of these crops are needed because weeds have become resistant to “Round Up” (glyphosate). The new products are called “Enlist.”
First let’s get a few facts straight. When crops are genetically modified to resist weed killers they do not contain the weed killer in their plant parts. Just like some tomatoes have resistance to blight and other tomato diseases, these new plants resist dying from 2-4-D. In this case a bacterial aryloxyalkanoate dioxygenase gene is added to help them survive 2-4-D. When sprayed with 2-4D the corn or soybeans don’t die. The weeds around them however will die. Because it takes a lot of money and time to develop resistant crops these plants are usually patented.
2-4-D is a common agricultural chemical and is currently being used on many agricultural fields. It can’t be applied directly to some crops of course, because it kills some plants (like corn and soybeans.) It is usually used to burn off weeds before a crop is planted. 2-4-D is a very common ingredient in lawn care products, like “Weed and Feed” and “Weed Be Gone” and homeowners use a lot of it. Golf courses are literally doused in it. These products usually have other toxic ingredients as well.
Here’s the problem, as many see it. When crops can withstand a pesticide it is used on them. The corn you eat now is probably not very likely to contain high levels of 2-4-D on it because the pesticide would have been used well before the corn was planted. Now, because the pesticide might be liberally sprayed on corn fields, harvested corn could have the pesticide on it. The makers of the new plants claim that 2-4-D doesn’t enter the plants and doesn’t last long on the corn. But to many it seems that 2-4-D is much more likely to enter the food supply if it is applied to crops as they are growing.
2-4-D has a nasty reputation because it was half of the chemical concoction of a defoliant that was labeled “Agent Orange”. Agent Orange has been found to be responsible for many health problems including a number of cancers, to soldiers exposed to it during the Viet Nam War. However research has proven that it was dioxin, a contaminant of Agent Orange produced during its manufacture, which caused the problems.
Pesticide manufacturers claim that the method of producing 2-4-D they use now does not result in dioxin contamination. However some studies have shown some weed killer brands using 2-4-D do have dioxin contamination. And even if dioxin is absent 2-4-D is not a harmless pesticide.
2-4-D is not generally ingested, rather people get it in their systems by absorption through the skin and by breathing it in. The EPA has ruled that it does not cause cancer in humans. (But dioxin does.) Some scientists disagree. But we can’t legally test 2-4-D on humans by having them eat it. We can only test it on animals.
However persons who are exposed to 2-4-D in manufacturing plants and who are agricultural or lawn care personnel that are regularly exposed do have higher rates of amyotrophic lateral sclerosis. Studies have also confirmed that regular exposure to 2-4-D causes male reproductive problems, including defective sperm. Other studies have linked even smaller exposures to liver damage- including the study which claimed that golfers who regularly play on treated courses have higher rates of liver cirrhosis. It has also been linked to eye and lung damage.
Dogs are very susceptible to liver and other problems including rare cancers if they are exposed to lawns regularly treated with 2-4-D products. This is thought to be because they consume treated grass and lick themselves, ingesting the herbicide. (This is why you should never use these products on lawns that dogs use, despite the claims of lawn care companies.)
Farmers (or maybe just the companies who want to sell to farmers) say they need 2-4-D resistant crops because weeds have developed resistance to glyphosate. If they are able to rotate the two types of crops, glyphosate resistant and 2-4-D resistant, weed resistance to the pesticides is much less likely to develop. They point to the fact that 2-4-D has been used on crops since 1946 – without fanfare and without appreciable damage to the environment. And there is a good chance that any exposure to 2-4-D by the average consumer comes from their use of it at home.
If we do allow the growing of these new resistant varieties let's suggest a trade off. Let’s ban the use of 2-4-D on lawns, sports fields and golf courses. That would probably keep the level of 2-4-D used in the US the same as before the modified crops or even reduce it. Make it a restricted use pesticide that requires a licensed applicator. Homeowners are more likely to be exposed to 2-4-D from lawn care/ weed killer products than agricultural use and they are more likely to use these pesticides in careless and illegal ways.
Weed free lawns or golf courses are not a justification for pesticide use. If weeds bother you so much pull them by hand or use safer methods of getting rid of them such as vinegar. If we banned toxic chemical use on lawns, sports fields and golf courses we would reduce pesticide levels in the environment by at least 50%.
The USDA is still taking public comments on whether 2-4-D resistant crops should be grown until March 11. Here is the site where you are supposed to be able to leave those comments.
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