Seasons change, yet some things remain the same. Nearly half a century ago, Rachel Carson debuted the first serial installment of what would eventually become one of the landmark works of the 20th century, Silent Spring. In that book, Carson famously argued that the pesticide DDT was responsible for negative impacts on the environment, animals, and humans alike, despite disinformation spread by industry and government officials about its purported safety and utility in agribusiness. Silent Spring is often credited with starting the modern environmental movement, yet today we are facing equivalent challenges and similar campaigns to conceal the potential dangers of toxic chemicals in our midst.
In particular, the pervasive use of the herbicide atrazine raises a host of ecological and political questions that are strikingly reminiscent of those confronted by Carson. Perhaps coincidentally, the widespread use of atrazine in American agriculture dates to almost precisely the time that Silent Spring was beginning to take shape as a withering indictment of the chemical industry's blatant disregard for emerging health warnings and its concomitant influence over politicians and regulators. While DDT was eventually banned for use as a pesticide in 1972, atrazine has enjoyed decades of unfettered use as (according to its maker, Syngenta) "one of the most effective, affordable and trusted products in agriculture." This promotional website includes personal testimonials from farmers as well as press releases intended to debunk "baseless activist claims" about atrazine's safety.
Interestingly, a similar pattern was evident in the early days of Carson's work to expose the dangers of DDT, in which her perspective was considered so "heretical and controversial" that she couldn't readily find a willing publisher to bring the story to light. When Silent Spring was finally published in 1962, there was an immediate backlash from the chemical industry and its proponents in the Department of Agriculture, equal parts of which were aimed at debunking Carson's science and attacking her personally in an attempt to discredit her views. In a thinly-veiled invocation of the Enlightenment gendered view of nature, one prominent industry spokesman remarked as part of a concerted public relations effort: "If man were to follow the teachings of Miss Carson, we would return to the Dark Ages, and the insects and diseases and vermin would once again inherit the earth."
Despite such dire predictions and ad hominem recriminations, Carson never wavered in her views. One of the most powerful aspects of her analysis was the recognition that environmental issues are necessarily socio-political ones as well. Most of us (myself included) are not able to follow the purely scientific components of any debate about the safety and efficacy of a given industrial chemical. Indeed, it is likely that competing research claims will be made, with industry oftentimes directly employing "think tanks" to generate or recast findings to undermine the force of contrary claims about its products. To sort these contests out and protect the population's interests, we generally must rely on regulatory bodies such as the Environmental Protection Agency (EPA), which actually traces part of its roots back to Carson and even has been referred to as "the extended shadow of Silent Spring."
Unfortunately, the EPA frequently aligns itself with commercial interests in the face of studies suggesting problematic effects of highly profitable and widespread agricultural chemicals such as atrazine. In 2003, the Natural Resources Defense Council (NRDC) reported that the EPA had decided not to regulate or otherwise limit the use of atrazine despite growing concerns about its potential effects on humans and the environment, including its impact on water systems from agricultural runoff. The NRDC, in a manner that will figure into the current debate, described these concerns as follows:
"Several recent studies show that atrazine causes sexual abnormalities in frogs, and another revealed elevated levels of prostate cancer in workers at an atrazine manufacturing plant. Some of the findings resulted from research funded by the manufacturer itself.... One of the first of several studies to turn up evidence of sexual deformities in frogs exposed to atrazine was conducted by Dr. Tyrone Hayes [who] conducted initial research with funding from Syngenta, and the deformities he found in the frogs included hermaphroditism. Syngenta responded by repeatedly sending him back to re-run his research, and apparently did not submit the findings about hermaphroditism to the EPA. Frustrated by the delays, Dr. Hayes eventually gave up his Syngenta funding, ran the experiments again independently, and found the same results. Since then, Syngenta-funded researcher Tim Gross has reported similarly damaging effects to a different species of frogs exposed to atrazine...."
This 2003 report further cited a study from the Journal of Occupational and Environmental Medicine that suggested a link between atrazine and prostate cancer in humans. In light of such potential issues arising from groundwater contamination, in 2005 the European Union banned the use of atrazine as a precautionary measure. Nonetheless, in 2006 the EPA re-registered its use in the United States. In recent weeks, however, a number of new studies have emerged that cast further doubt upon atrazine's safety, including (as reported by Reuters) studies indicating increased rates of birth defects: "Atrazine ... upped the risk of nine birth defects in babies born to mothers whose last menstrual period was from April to July -- that is, when surface water levels of the pesticide were highest. The U.S. Department of Health and Human Services' Agency for Toxic Substances and Disease Registry has also reported that high levels of the chemical have been shown to cause birth defects in animals."
Predictably, Syngenta issued a press release arguing that there was "no direct or credible link" between atrazine and the observed incidences of birth defects. The company's atrazine website continues to laud its agricultural benefits and the purportedly "overwhelming evidence" of its safety. In 2009, the New York Times reported that the EPA generally has sided with Syngenta in rejecting calls for regulation in light of emerging critical studies, but that it "is likely to be re-examined" by the new EPA administrator due to its widespread usage (not only agriculturally but on lawns, parks, and golf courses) as well as concerns voiced by officials in other agencies such as the Department of Health and Human Services. Still, the EPA is perceived as a relatively weak and highly politicized agency, casting doubt as to whether the so-called "extended shadow of Silent Spring" will in fact strive to uphold its legacy.
The mounting pressure may be difficult for the EPA to ignore, however, as indicated by news reports that "forty-three water systems in six states - Illinois, Indiana, Iowa, Kansas, Mississippi and Ohio - recently sued atrazine's manufacturers to force them to pay for removing the chemical from drinking water." Indeed, in 2009 the NRDC issued a comprehensive report on the presence of atrazine in watersheds, concluding that "approximately 75 percent of stream water and about 40 percent of all groundwater samples from agricultural areas tested in an extensive U.S. Geological Survey study contained atrazine." This in-depth report explores atrazine's endocrine-disrupting qualities, its pervasive appearance in high levels in drinking water systems, and the EPA's permissive standards and general neglect of the problem. The recommendations offered by the NRDC include "phasing out the use of atrazine, more effective atrazine monitoring, the adoption of farming techniques that can help minimize the use of atrazine and prevent it from running into waterways, and the use of home filtration systems by consumers." A follow-up article by one of the report's authors further notes that atrazine "can be detected in most streams and rivers of the U.S.," and that eventually much of it makes its way to the Gulf of Mexico, "where it continues its plant-killing spree of algae and other beneficial water plants that provide food and oxygen for aquatic life."
Equally compelling are recent studies - including those directed by former Syngenta researcher Dr. Tyrone Hayes of the University of California at Berkeley - indicating that frogs absorbing atrazine through their skin can be feminized even to the point where males are "functionally female" enough to lay eggs. According to Hayes, as reported in the Washington Post, even at trace levels that are within drinking water standards, male fertility rates among subject frogs are significantly diminished. Hayes has been conducting these studies and finding similar results for many years, and recently told me that further research has found that "atrazine induces infertility, prostate cancer, and breast cancer in rats and is associated with these diseases in humans in several published studies." In words that echo the spirit of Silent Spring, Hayes told the Post that atrazine is a chemical "that causes hormone havoc. You need to look at things that are affecting wildlife, and realize that, biologically, we're not that different."
The company of course rejects such notions, and referred the Post reporter to a professor who questioned Hayes's findings even as it was noted that this professor "had received funding from Syngenta for previous research, but that it had not biased his work." Respected publications such as Proceedings of the National Academy of Sciences and the Journal of Experimental Biology, however, have carried Hayes's reports and thus given imprimatur to his operative conclusion that "atrazine is a likely contributor to worldwide amphibian declines." In a recent email interview with me, Dr. Hayes further noted that these results have been confirmed by "independent labs," and that "the induction of aromatase and estrogen production has been demonstrated ... in fish, frogs, alligators, birds, turtles, rats and human cells." As a recent article in Science Daily explains:
"Some 80 million pounds of the herbicide atrazine are applied annually in the United States on corn and sorghum to control weeds and increase crop yield, but such widespread use also makes atrazine the most common pesticide contaminant of ground and surface water, according to various studies. More and more research, however, is showing that atrazine interferes with endocrine hormones, such as estrogen and testosterone - in fish, amphibians, birds, reptiles, laboratory rodents and even human cell lines at levels of parts per billion. Recent studies also found a possible link between human birth defects and low birth weight and atrazine exposure in the womb. As a result of these studies, the Environmental Protection Agency (EPA) is reviewing its regulations on use of the pesticide. Several states are considering banning atrazine, and six class action lawsuits have been filed seeking to eliminate its use. The European Union already bars the use of atrazine."
In response, Syngenta issued a press release, remarkably claiming that a "growing body of research shows that atrazine has no effects on amphibians" and that "scientists around the world have shown that atrazine is safe to use - providing farmers an important tool to bring us safe, abundant and nutritious food." In an attempt to discredit Hayes in particular, the release contends that his work "has many shortcomings that undercut its usefulness, including its inconsistency with prior findings by the author." Hayes flatly rejects this, telling me that he has no doubt about the consistency of his findings: "Our previous studies showed that metamorphs (juveniles) were demasculinized and partially feminized (hermaphrodites). Our new data shows that when these animals reach sexual maturity they continue to be demasculinized and some which probably start out as hermaphrodites are completely feminized. I have no idea what their proposed contradiction is." While no further details are offered by Syngenta about Hayes's results, which have been published in noteworthy journals for many years, the company concludes its press release with a self-promotional blurb that is full of its own contradictions:
"Syngenta is a responsible company. We take the stewardship of all our products seriously - and atrazine is no exception. Our 4,500 employees across the United States share a common purpose - bringing plant potential to life. We all have families, so we are all interested in seeing that atrazine is properly regulated in the water we drink. We are convinced that it is. We all enjoy the safe and abundant supply of food that our products bring to our tables. Syngenta is one of the world's leading companies with more than 25,000 employees in over 90 countries dedicated to our purpose: Bringing plant potential to life. Through world-class science, global reach and commitment to our customers we help to increase crop productivity, protect the environment and improve health and quality of life."
Indeed, contesting research methodologies and asserting that there are "problems" with any studies contradicting its marketing line have been standard practices for Syngenta, as the New York Times noted in 2009: "In written statements, the E.P.A. and Syngenta argued there were problems with all of the studies suggesting health risks from low doses of atrazine. Agency officials pointed out that epidemiological findings cannot fully differentiate between multiple influences, and that they only highlight associations, and do not demonstrate a cause-and-effect relationship...." The Times, however, asked six leading researchers to review the epidemiological studies, and they concluded that the results were troubling. "These suggest real reasons for concern," said Melissa Perry, an associate professor at the Harvard School of Public Health. "The results need to be replicated, but they suggest there are real questions for policy makers about what constitutes safe levels of atrazine." The article continued:
"Recent studies suggest that when adults and fetuses are exposed to even small doses of atrazine, like those allowed under law, they may suffer serious health effects. In particular, some scientists worry that atrazine may be safe during many periods of life but dangerous during brief windows of development, like when a fetus is growing and pregnant women are told to drink lots of water.... In recent years, five epidemiological studies published in peer-reviewed journals have found evidence suggesting that small amounts of atrazine in drinking water, including levels considered safe by federal standards, may be associated with birth defects - including skull and facial malformations and misshapen limbs - as well as low birth weights in newborns and premature births.... Some of those studies suggest that as atrazine concentrations rise, the incidence of birth defects grows."
Like most of us, I'm not a biological scientist and thus must rely on others to bring their expertise to bear on important issues such as this. I do know that corporate obfuscation and regulatory cronyism have been recurrent features of the post-Silent Spring landscape. If there is even a chance that one of the most widely-used agricultural chemicals is contributing to increased rates of cancer and birth defects, plus decreased fertility rates in numerous species, it warrants serious scrutiny. As Hayes related to me: "I believe that the preponderance of the evidence shows atrazine to be a risk to wildlife and humans. I would not want to be exposed to it, nor do I think it should be released into the environment." If a former corporate-funded and well-respected researcher continually warns of its usage, the U.S. should consider following the E.U.'s example and ban atrazine's use even if only as a precautionary measure. If our food and water supplies indeed are increasingly becoming toxic, we need to step back and consider the implications for the potential survival of the species itself. "We are subjecting whole populations to exposure to chemicals which animal experiments have proved to be extremely poisonous and in many cases cumulative in their effects," Carson wrote in Silent Spring. "These exposures now begin at or before birth and - unless we change our methods - will continue through the lifetime of those now living." We can, and must, change our methods before it's too late.
While her landmark book was inspired in its title (from a line in a John Keats poem) by the notion of waking up to a spring season in which no bird songs could be heard, Carson was likewise motivated by the toll that industrial chemicals could take on human life as well. This spring, in recognition of Carson's legacy, let us vow not to remain silent in the face of increasing threats to our health and wellbeing. We owe at least this much to ourselves and to the world we'll leave behind for our children. Let's hope that the future is filled with clamorous and boisterous springs from here on out.