Silent Spring’s 50th anniversary: What would Rachel Carson say now?
When I was a graduate student at the University of Kansas, the pesticide DDT was very much on my mind. My assistantship in 1953 involved research on the evolution of DDT-resistance in fruit flies. It quickly became clear to all of us in this research group that the broadcast use of pesticides was a losing and dangerous game. When I attempted to raise butterflies in New Jersey in the 1940s, bringing food plants in from nature usually resulted in the caterpillars dying. In those days, widespread spraying of DDT to control mosquitoes coated much of the countryside with poison. In the lab it was easy to use selection to make flies impervious to DDT in some 10 generations, or, in contrast, so susceptible that they would drop dead at a whisper of that “miracle” chemical’s name. Evolution of resistance tended to make continuous use of any pesticide inefficient. The usual response of the chemical industry was to recommend increasing the dose or to substitute more toxic compounds, making pest control even more expensive and dangerous.
That was well understood by evolutionists early on, but it took a marine biologist and talented writer, Rachel Carson, to bring the pesticide problem to public attention and, incidentally, to launch the modern environmental movement. Silent Spring, published in September, 1962, was a brilliant book, but also one that appeared when the time clearly was ripe. The public seemingly had been primed by publicity about radioactive fallout, fears of pesticide residues on cranberries and the thalidomide scandal, the latter enhanced by pictures of infants born with distorted limbs. Carson suffered from the drawbacks of being a female scientist before science’s gender gap began to dissolve, and from lacking a PhD and a professorial position. Despite those “handicaps,” she had the science about as right as it could be at the time.
Carson was subject to a storm of vicious attacks by the combined public-relations machines of the chemical industry and agribusiness, and even from scientists in the industry and entomology departments of some universities. Typical was the much quoted statement of Professor Robert H. White-Stevens, a poultry scientist of Rutgers University: “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.” The assault began even before Silent Spring was published. A public-relations campaign against Carson and trumpeting the safety of pesticides was bankrolled by the National Agricultural Chemical Association (NACA). Virtually all of the attacks were without merit. Carson withstood them all, even though she was struggling with metastatic cancer. I met her once only briefly, and then she was gone.
Rachel Carson’s legacy looms huge today. Many people have the impression that climate disruption is the worst environmental problem humanity faces, and indeed, its consequences may be catastrophic. But the spread of toxic chemicals from pole to pole may be the dark horse in the race. Carson may have started environmentalism by illuminating exactly the right issue. This is especially the case as recent research has shown that many synthetic chemicals, called endocrine-disrupting compounds, may do nasty things to you at high doses but can have different harmful effects at very low doses. These low-dose effects can increase the probabilities of altered sex determination, behavioral changes, developing cancers and more.
A mass of evidence should alert humanity to the risks of toxifying Earth from pole to pole with synthetic chemicals. For instance, Tyrone Hayes of the University of California, Berkeley, has suffered Carson-like abuse by flacks for the chemical industry for demonstrating nasty low-dose impacts of the near-ubiquitous herbicide atrazine in both the laboratory and in nature. Atrazine is manufactured by Syngenta, which has bankrolled a multimillion-dollar campaign hiring pundits to lie about atrazine and besmirch Hayes. The campaign resembles that of the well-funded fossil-fuel industry assault on climate disruption and also the tobacco industry’s perpetual storm of lies about the safety of smoking. Hayes has been, as was Rachel Carson, scientifically vindicated, and like Carson, is one of my heroes.
Infant mosquito fish exposed to small doses of 4-nonylphenol, a widely used industrial chemical, produced adults all with the female phenotype although the normal 50-50 male-female ratio persisted in the sex organs. In the wild, a high frequency of alligators in a Florida lake polluted with an endocrine-disrupting pesticide had developmental abnormalities leading to sterility. A recent, thorough review of the literature documented the pervasive evidence for low-dose effects in populations of human beings and of wildlife. One of its conclusions (conservative in my view) is that “regulatory action to minimize or eliminate human exposures to endocrine disruptors could significantly benefit human health.” Today humanity is faced with a series of epidemics in which toxics may be involved: asthma, autism, hormone-related cancers, ADHD, heart disease, autoimmune diseases, obesity, Type 2 diabetes and learning disabilities, just to name a few. Of course, toxics may be found innocent in many cases, but is it wise to keep releasing them ad lib into the environment on the assumption they are not involved?
Carson was properly concerned about the problems of unknown interactions among mixtures of novel chemicals in the environment. Today, with the potential for millions of possible synergisms among the tens of thousands of compounds already released, just identifying the culprits would be an enormous challenge. And if they were identified, removing them from the environment could be an even more monumental task, or most likely prove impossible.
What should be done? In my view there are two basic solutions to situations where the activities of a segment of the human population, often an industry, present a clear and present threat to the human future as once the manufacture of chlorofluorocarbons did in threatening the ozone layer. One answer lies in society finding ways to alter the behavior of the industry to minimize the impacts on those involved. Society needs energy, but it can no longer afford to mobilize it by burning fossil fuels. John Browne had the right idea when he changed British Petroleum Corporation into BP Corporation and gave it the slogan “Beyond Petroleum.” Society needs some synthetic materials, but it can no longer afford to manufacture and distribute them as incautiously as it now does.
Browne’s approach didn’t last at BP, but perhaps converting the toxics producers to “green chemistry” could be a permanent step forward. The idea would be to make the basic ingredients of American prosperity less toxic or non-toxic. This would shift the environmental issues in molecular design upfront. Green chemistry has great promise as a path toward inherently safer materials, but it faces serious impediments. One of the biggest and most immediate is that the field lacks the capacity, in terms of trained people, to ask the right questions and generate workable solutions. At a time when American science education is on the wane and when U.S. industrial jobs are fleeing overseas, this scientific industrial revolution could breathe new life into a sector of industry that may otherwise be doomed to obsolescence and decay.
In an era of exploding populations and escalating resource scarcities, the pressure to produce many substances with known or possible toxicities will probably grow, and grow much more rapidly than scientists can even estimate the risks. This is especially so in view of the myriad potential but unknown synergies possible in the global stew of toxic substances. One solution is to invoke the precautionary principle, by prohibiting all discharge of persistent organic pollutants and rapidly phasing out production of the most dangerous classes of compounds, such as organochlorines. This would shift the burden of proof from having to demonstrate that a chemical is dangerous to requiring it be shown to be safe, although admittedly, criteria would be difficult to establish.
The second and more fundamental answer, I believe, is that the global system needs to be rescaled. It is now in serious overshoot, with more than one Earth now required to support just today’s population indefinitely. Humanity seems to be moving fast away from sustainability, and symptoms of collapse are becoming common. To see that, one need only compare the first oil well, which went down 69.5 feet from Earth’s surface to strike oil, with Deepwater Horizon, which started a mile under the sea and drilled a couple of miles deeper. A gradual, humane reduction of human population, and a reduction in over-consumption by the rich, would greatly alleviate pressure on the chemical industry to keep churning out dangerous chemicals. I imagine that Carson, with her population-oriented discussion of pesticide problems, would be very sympathetic to such a rescaling. “Populations are kept in check by something the ecologists call the resistance of the environment,” she noted, “and this has been so since the first life was created.”
Of course, as Carson’s critics realize, this would have serious financial consequences for the chemical industry, and could result in considerable inconvenience for consumers. To avoid that, one possibility is to pursue business as usual and count on luck to save civilization. Maybe no truly lethal synergies will turn up, or no new chemical will become global before it is discovered to cause untreatable cancer. Maybe the poisoning of nonhuman organisms will not collapse ecological systems – as appears to be happening with bees today – and bring down civilization. Perhaps advances in molecular biology will identify and neutralize any dangerous new compounds or cure any serious diseases that appear.
And perhaps they won’t. Is it wise to sit by and not take substantial measures? In democracies, the decision rests ultimately with the citizens; I think it is crystal clear what Carson would have recommended.
This article originally appeared at www.environmentalhealthnews.org on June 25, 2012.
PHOTO: Silent Spring, by Rachel Carson, published 1962 by Houghton Mifflin.