As weeds and bugs evolve to resist the poisons designed to destroy them, farmers may be forced to turn to an old and toxic herbicide that has been connected to multiple health and environmental complications.

Monsanto's Roundup has been farmers' herbicides-of-choice for years and is so effective that Roundup itself created its own line of seeds that are genetically engineered to withstand the herbicide. The invention of the Roundup Ready seeds allowed large-scale farmers to simply douse their fields with Roundup, which would kill off all plant life except the desired crop.

Roundup Ready corn, soy and cotton is now a staple for U.S. farmers. The U.S. Department of Agriculture reports that 94 percent of soybeans and 70 percent of corn and cotton planted in the nation are genetically-altered Roundup Ready products.

Years of exposure to Roundup has led to the development of Roundup-resistant weeds.  The Southeast Farm Press reports that researchers from the University of Illinois have suggested that farmers turn back to an herbicide that is largely considered to be a dinosaur: 2,4-D,  one of the active ingredients in the Agent Orange defoliant that was disastrously used during the Vietnam War.

The Vietnam Red Cross reports at least 3 million people in the country have been affected by Agent Orange -- which the U.S military used to douse chunks of the Vietnamese countryside during the war -- including hundreds of thousands of children who have been born with birth defects due to high dioxin exposure.

Herbicide Resistance May Lead to Return of 2, 4-D?

Farmers can't imagine going back to 2,4-D or other auxin herbicides, Dean Riechers, a University of Illinois associate professor of weed physiology, told the Southeast Farm Press. But herbicide resistance is bad enough that companies are willing to bring it back. That illustrates how severe this problem is.

2, 4-D has been connected to the development of non-Hodgkin's lymphoma and other cancers, according to a 2004 report from Beyond Pesticides. It contains several forms of dioxin, a dangerous environmental pollutant that the World Health Organization reports is mainly exposed to humans through food and has been linked to reproductive and developmental problems.

Moreover, Beyond Pesticides reports 2, 4-D it an endocrine disruptor, meaning it can interfere with the body's hormone messaging system and alter essential processes.

Workers who apply 2,4-D had a higher number of white blood cells with multiple nuclei than people who were not exposed. In rabbits, 2,4-D exposure resulted in unusual numbers of chromosomes in brain cells. Genetic problems like these can have further consequences in terms of cancer and reproductive problems, the report states.

EPA Ruling

In 2007 the U.S. Environmental Protection Agency ruled that there was not enough conclusive evidence to prove that 2,4-D exposure is linked to human cancer development.

The EPA did not immediately return a request for comment on the issue.

The Southeast Farm Press reports that the agrichemical industry has long since stopped trying to develop new, less toxic herbicides that could serve as a replacement for Roundup, which is why 2, 4-D is even being considered. Reichers told the source that farmers' next best chance is to mix glyphosate -- which is used in Roundup -- and another herbicide with minor resistance problems.

For some growers, this technology may be worth the risk because they have no other choices, Reichers said.