"This is not what Rachel Carson would have wanted for her 50th anniversary present."
Mardi Mellon, senior scientist with the non-profit Union of Concerned Sciences, referred to the pending rollout of crops engineered to be resistant to "one, two, three, perhaps more herbicides." The resultant "dousing" of crops with larger quantities of a multiple poisons, Mellon said, is not exactly the future Carson sought with the publication of her landmark book, "Silent Spring," on Sept. 27, 1962.
Thursday's anniversary comes as debate over the healthiness of conventional, genetically-modified foods has arguably reached record decibels -- thanks in part to the publication this month of two controversial studies. One concluded that organics offered no better nutritional value than conventional foods; another suggested that genetically modified corn increased cancer in lab rats.
Lost in this debate, some experts said, is a more fundamental issue facing the food system and public health: a vicious cycle of chemical-dependency that we can't seem to break, even 50 years after Carson warned of the dangers of an arms race against nature we are destined to lose.
The marine biologist may have been among the first scientists to refer to the "pesticide treadmill," as well as to suggest that the chemical industry keeps it running by "pouring money into universities to support research on insecticides."
Many scientists repeat those insights today.
"Herbicide resistance is not new. We've been dealing with it for about 50 years," said Mike Owen, a weed expert at Iowa State University. "But every time we've ended up with resistance in particular weeds, industry would bring forward a new solution -- so it again became a non-problem."
It is evolution on a small scale: Repeated application of a herbicide literally weeds out the weak weeds and gives the rare resistant weeds the opportunity to reproduce and eventually dominate.
The latest example is a proliferation of weeds resistant to Monsanto's Roundup. Use of the popular herbicide dramatically increased beginning in the mid-1990s with the introduction of crops genetically engineered to resist the chemical's effects.
As it rolled out the Roundup-resistant seeds, Owen recalled, Monsanto dismissed warnings from him and others that weeds may develop resistance. Now, with Roundup-resistant weeds a reality, and without any new chemical tools to take its place, agriculture is looking back to 2,4-D, dicamba and other old herbicidal weapons that experts warn could be more hazardous to public health. Roundup itself has been shown to disrupt human hormones and cause birth defects.
Dow AgroSciences and other biotech companies are expected in the next year or two to roll out genetically modified organism seeds -- so-called GMO seeds altered to resist one or a combination of herbicides.
"Obviously, they are looking forward because of concerns that exist with evolved resistance," said Owen. "But, look, they also want more products to sell. Seed companies are synonymous with chemical companies -- it makes a great package."
Owen predicted that farmers will likely "see the same thing happen again" with the new seeds. Resistance to 2,4-D has already been reported, although not yet in weeds that trouble the relevant crops.
"These new crops that are coming out of the biotech companies are going to be Rachel Carson's worst nightmare," added Mellon. "We'll be using far more pesticides than we have in the past."
Recent research has estimated an increase in herbicide and pesticide use of about 400 million pounds over the first 16 years of GMO commercial use, despite an initial drop when the seeds were first introduced. Increasing resistance among insects and weeds, experts said, has led farmers to apply larger quantities of chemicals to achieve the same level of pest and weed control.
Owen isn't necessarily concerned with the use of chemical weed control. He pointed to the Stanford study as assurance that "food is food," and highlighted the concerns about the French study's methods. However, he agreed that we need to incorporate chemical-free strategies, such as rotating crops and encouraging natural pest predators, rather than relying solely on poisons. David Pimentel of Cornell University wrote in an editorial published today that "Pesticide use worldwide could be reduced 50 percent and still achieve effective pest control," based on successes in Sweden and Indonesia.
"At the end of the day, we're still going to need to use some pesticides in some situations some of the time. It could just be many-fold less," said Mellon.
Mellon and Owen said they recognize that agricultural research remains influenced by chemical companies with a vested interest in maintaining demand for pesticides, as Carson suggested 50 years ago.
"Funding from the government to conduct research is at an all-time low," said Owen. "In many instances, a lot of the funding we get at land-grant universities to do research [on a product] is from the company" producing the product.
Owen noted that he has published research that companies haven't liked. He also said he's been threatened with lawsuits and nearly fired over that research -- responses similar to what Carson received from pesticide manufacturers after publication of "Silent Spring."
"Right now, if you’re a scientist looking into the potential harmful effects of pesticides, it's a hard road," said Mellon.
Few know this better than Tyrone Hayes, a biologist at the University of California, Berkeley.
In 1998, Hayes was hired as a consultant to conduct research for the chemical company Syngenta. His study discovered that the company's prize pesticide, atrazine, may disrupt hormones. In some cases, exposed male amphibians turned into females, he found.
"The company didn't like that too much," Hayes said. Because the research by contract belonged to Syngenta, it was never published.
Hayes eventually found funding from other private sources, repeated the atrazine study and published his results. Now, 14 years later, he said he still faces intimidation from the chemical industry.
Hayes said a "number of scientists in academic labs" accept their relationships with industry and play by the companies' rules.
Carson had already recognized this predicament among academics 50 years ago: "Can we expect them to bite the hand that literally feeds them?"