THIS LAND — ABBEY, CARSON, AND LEOPOLD: Rachel Carson's Legacy

Critics and historians usually refer to Rachel Carson as a nature writer first, and a scientist second. Indeed she gave us vivid descriptions of the sea and the life that indwells the oceans, but I believe her influence reaches far beyond the simple boundaries of nature writer, even scientist. Rachel Carson left unparalleled legacies in the fields of science — particularly ecology — environmental policy, and feminism. Furthermore, she achieved them through writing, surely her most important legacy.

If there is any one character that best exemplifies Carson's life, it must be that of the female Anguilla eel, here described in Under the Sea Wind:

But the females would press on, swimming up against the currents of the rivers. They would move swiftly and by night as their mothers had come down the rivers. Their columns, miles in length, would wind up along the shallows of river and stream, each elver pressing close to the tail of the next before it, the whole like a serpent of monstrous length. No hardship and no obstacle would deter them.

This was the task set before Rachel Carson as she set out to fight the currents of a male-dominated techno-industrial world bent on destroying the environment, not to mention a woman's determination to succeed in that environment. That Carson attempted the journey is remarkable in itself. That she succeeded to the degree that she did is the stuff of legends.

She left behind a trail of environmental legacies without match. In her wake we find sweeping legislative acts that inalterably changed the direction of environmental policy, including formation of a Federal government agency dedicated to administering several environmental laws, the Environmental Protection Agency or EPA.

As a scientist she was one of the very first to survey the then-current research on chemical pesticides. She announced the carcinogenic nature of pesticides to a public that was completely unaware (and happily uncaring) about their long-term effects. She developed a convincing argument along five lines of evidence. First, the chemical industry had created countless new artificial substances in less than half a century. Second, the world's entire population had experienced unprecedented exposure to many of these chemicals through their indiscriminate application in the name of health, welfare, wealth, and convenience. Third, there was considerable evidence of increases in the incidence of cancers in humans simultaneous with these exposures. For example, white males born in the 1940s exhibit twice the incidence of non-tobacco-related cancer than their grandfathers. Biologist/poet Sandra Steingraber explains the relevance of this line of evidence thusly:

The rise in cancer incidence over calendar time is one line of evidence that implicates environmental factors. The increase in cancer incidence among successive generations is another. A third line of evidence comes from a close consideration of the cancers that exhibit particularly rapid rates of increase.

Carson realized the importance of this last point and emphasized the increased rate of incidence for leukemia, in the general population as well as among those involved in the manufacture and application of chemical pesticides. This also recognizes the relevance of spatial qualities to rising cancer rates in addition to the temporal qualities. Industrialized countries have disproportionately higher rates of cancer, and people who work with these chemicals have yet disproportionately higher rates than their less-exposed neighbors. Subsequent to Carson's research, the World Health Organization has concluded that over 80 percent of all cancer is attributable to environmental factors.

Fourth, Carson used then-recent results from experiments on laboratory animals to show strong correlations between low doses of pesticides and higher rates of cancer in mammals. Fifth, she explained how the inner workings of the cell could lead to cancerous tumors through chromosomal damage, hormonal disruption, and metabolic alteration.

Carson's legacy as a scientist continues through the work of contemporary female scientists researching and writing about damage to the environment via chemical pesticides. In Living Downstream, Sandra Steingraber ignores Carson's precedent of not admitting her own battle with cancer. Steingraber tells the story of environmental links to cancer through the eyes of a scientist recovering from cancer herself. She points out that Carson kept secret her own illness in order to "retain the appearance of scientific objectivity," but, strangely, Steingraber felt that her own work did not require this level of objectivity.

Steingraber gives the reader a course in organic chemistry, much like her mentor. She straightens out several definitions used interchangeably by laymen: To a chemist, the term organic simply refers to a carbon compound while synthetic refers to any artificially formulated compound. Thus, to a chemist, a compound can easily be both organic and synthetic. This differs from the biologist's definition for organic, which would include only those compounds derived from organisms. For the biologist, and for the population at large, organic and synthetic are mutually exclusive. Steingraber goes on to explain how organic (using the chemist's terminology) synthetic compounds came to be so entwined in the fabric of modern life, including the rise of the petrochemical industry as a result of the scarcity of whale oil in the 19th Century. She falls short of carrying the history lesson through to the Western world's transformation from a carbohydrate-based economy to that of a hydrocarbon-based economy, preferring, instead, to call it a petrochemical-based economy.

Carbohydrates are organic compounds made up of carbon, hydrogen, and oxygen, including sugars, starches, and celluloses. Hydrocarbons, on the other hand, are not necessarily oxygenated, that is, they can be made up of only carbon and hydrogen molecules, including fossil fuels such as coal, natural gas, and gasoline. That much of our hydrocarbon consumption is satisfied through the refinement of petroleum does not thoroughly explain our economic transformation. Ultimately, the transformation is one of utilizing resources long-dead rather than resources that were recently alive. In applying financial terms to natural resources, the carbohydrate-based economy lives off of the planet's interest. The hydrocarbon-based economy consumes capital. This radical change in the basis for supporting life goes unmentioned by Steingraber.

While an omission of this scope is forgivable, Steingraber's work remains largely unreadable due to several errors committed as a writer, not as a scientist. First, she meanders through her argument in a way that Carson would have deemed unacceptable. Nonlinear expression is better left to the arts than to science. Second, the reader is left with the impression that Steingraber is using environmental science to complain about her fate as a victim of cancer. This simply destroys any "appearance of scientific objectivity." Subjective accounts should be stated elsewhere, leaving the field of environmental science untainted. Steingraber really should have stuck to Carson's examples in clearly stating her argument in a linear fashion that is completely objective.

Carson also hinted at genetic effects caused by the indiscriminate use of chemical pesticides. As it happened, Silent Spring was published at the same time the thalidomide story was breaking, and the two were not unrelated. Thalidomide was prescribed to prevent morning sickness and enhance sleep in pregnant women. Unfortunately it resulted in birth defects, such as unformed limbs, previously unseen on such a large scale. It was followed closely by another medical scandal, that of DES, which had been prescribed for the prevention of miscarriage for over thirty years and was now blamed for sterility and even premature death due to genital cancers in women who came to be known as "DES daughters." Both of these medical disasters proved the fallaciousness of the so-called placental barrier that was supposed by medicine to protect the fetus from injury by the mother. Carson foresaw similar problems due to the mother's exposure to environmental insults of a pesticidal nature.

In Our Stolen Future, Theo Colborn, Dianne Dumanoski, and John Peterson Myers explore this area of Carson's research. Colborn is the primary researcher on this project, a woman who did not begin her graduate studies until the age of fifty-one but persevered through a master's in ecology and a Ph.D. in zoology. She found work with the Conservation Foundation, studying air pollution and water purification efforts on the Great Lakes, but kept getting sidetracked by data showing something seriously wrong in the region's wildlife. While the problem of thinning eggshells in eagles had been reversed with the ban of DDT in 1972, other birds and wildlife were still showing abnormalities: vanishing mink populations, unhatched eggs in herring gull colonies, and physical deformities in cormorants. There seemed to be a pattern of genetic disorders due to hormonal disruptions that Colborn could not dismiss, even if she could not pin down the source. Finally, she concluded that the hormone mimicking characteristics of many organic chemicals had become magnified through the food chain, as explained in Silent Spring, to the point that they were wreaking havoc among Great Lakes inhabitants decades after the chemicals themselves, now outlawed, had been discharged into the environment, often from points thousands of miles away. Where Steingraber writes about Carson's forecast for the current generation, Colborn explains Carson's predictions for the next generation. And it doesn't look good.

Colborn refers to the DES experience to describe the state of medicine, past and present. Before DES, a chemical was considered safe "unless it caused immediate and obvious malformations." After DES, scientists realized that the effects of a chemical may not show themselves in the current generation, and may not even reveal themselves until the next generation attempts to conceive. The delayed reaction of DES demonstrated that chemicals could cross the placenta, disrupt the development of the baby, and have serious effects that might not be evident until decades later.

The route taken by such chemicals was also new. Not toxic, and not necessarily carcinogenic, these synthetic hormone disruptors work their black magic by imitating estrogen, the female hormone required for conception and the successful development of the fetus in the womb. Estrogen mimics are found throughout nature, often used by plants to protect themselves from predatory herbivores. Clover produces formonenetin, an estrogenic compound, to reduce predation by causing sterility in sheep, a very clever, farsighted defense mechanism. Fortunately the sheep population can regain its viability by eating something else — not so when the estrogen mimic is applied indiscriminately to the environment at large.

DDT was discovered to have estrogenic qualities in 1950. That discovery led to research on other organic compounds, including PCBs (polychlorinated biphenyls) and dioxin, both of which are excellent estrogen mimics and are both widely distributed throughout the environment. Carson did not think to include PCBs because the insulating compound was not thought to be poisonous at the time. With hormonal disruptors what matters even more than the toxicity or carcinogenicity of a compound is its ability to persist in the environment. PCBs simply do not break down in human time frames and will remain in the food chain for as long as life exists on earth. Their fat solubility ensures their presence in the current generation will be magnified at each higher link in the food chain, and will be passed to the next generation through the placenta and breast milk in mammals. Dioxin, long known to be toxic as well as carcinogenic, may prove to be most dangerous to life on earth in its capacity as a persistent hormone disruptor.

Evidence of hormone disruption is not limited to females. Declining sperm counts have been found in men living in industrialized countries, along with rising rates of testicular cancer, prostate cancer, and other reproductive abnormalities. Cases of hermaphrodites, once considered a biological rarity, are now regularly recorded in areas polluted by estrogen mimics.

The key to persistence in the environment is fat solubility. Organic compounds are attracted to fatty tissues, which, as carbohydrates, are themselves rich in carbon. Pesticides and other organic compounds are stored in these fatty tissues until the fat is drawn down. In mammals this occurs during gestation through placental conveyance of nutrients and in the production of breast milk, thus ensuring that organic compounds ingested by the mother will be passed to the newborn. Every child conceived since the mid-20th Century received his or her first dose of DDT, PCBs, and dioxin before he or she was even born, and got the second dose while nursing.

Clinical studies have shown definite links between estrogen and cancer. Prostate cancer in rats is induced by long-term exposure to estrogen. Breast cancer cells have been found to proliferate wildly in petri dishes when exposed to estrogen. Synthetic estrogenic compounds are often even more potent in this regard than natural estrogen.

Other effects of hormone disruptors have been found as well. Lower birth weights have been found in babies delivered by women who eat large quantities of fish caught in Lake Michigan, known to be polluted with heavy concentrations of PCBs. Hyperactivity and attention deficit have been linked to PCBs and other organic compounds, in addition to other behavioral and neurological problems.

Colborn concludes that the chemical messages required to sustain life in the current generation and successfully procreate succeeding generations may be disrupted by persistent organic compounds first decried by Rachel Carson. She exhorts the scientific community to move beyond the cancer paradigm — tragic on the personal level, not the species level — to look harder at hormone disruption, which acts on the species level. They offer methods for defending ourselves: Know the quality of water you drink. Choose foods low in persistent organic compounds. Reduce the contamination of food through plastic packaging (never microwave food in plastic — always use glass). Avoid unnecessary exposure by washing your hands and always assume pesticides are unsafe. But ultimately we must eliminate the hubris that has allowed the production of persistent organic compounds. At the heart of the solution lies a change in philosophy in which we must question our right to alter the environment.

Colborn's follow-up to Silent Spring is thoroughly researched and highly compelling. The editing is uneven and sometimes sloppy, but overall the book is highly readable for its genre. The authors are careful to state their arguments clearly in a linear format, and if any of them knowingly suffers from the effects of persistent organic compounds in the environment they do not let on.

Rachel Carson gave the public one of its first scientific treatments of ecology. Colborn refers to this new knowledge as a "watershed in the relationship between humans and the Earth." Our whole perspective has changed, and Carson was highly influential in bringing about this change. Without Silent Spring we would not likely have entertained the Gaia hypothesis, put forward by James Lovelock, whose original claim to fame was the discovery of CFCs (chlorofluorocarbons) throughout the Earth's atmosphere. While his theory of biogeochemical homeostasis is not universally accepted, Lovelock would not even have a platform from which to present his theory without Carson's precedent-setting work.

On the ground, however, Carson's greatest influence came as a result of the legislative actions taken in the wake of Silent Spring. She did not live to see the fruits of her labors, but they did indeed bear fruit. Her research on DDT was combined with corroborating evidence in the years immediately following Silent Spring, with the effect that registration for use of DDT in the United States was revoked in 1972. DDT is still manufactured for export and the established modes of transmission that Carson portrayed ensure that we are still affected by its use. Our exposure, however, is not nearly what it was before Silent Spring.

Other pesticides decried by Carson have also been banned. Aldrin and dieldrin were banned in 1975 except that aldrin, which converts to dieldrin in soil and fatty tissues, continued to be used as a termite poison until its complete ban in 1987. Lindane was banned in 1983 except for use in lice shampoos for humans and flea dips for dogs. Agricultural use of chlordane was stopped in 1980, while that of heptachlor ended in 1983.

This does not mean that all use of pesticides has been halted. Quite to the contrary, 99 percent of U.S. cornfields were sprayed with pesticides in 1993, as compared to less than 10 percent forty years earlier. In fact, current annual pesticide use in the U.S. amounts to about 8.8 pounds for every man, woman, and child. This may seem disheartening just when things were starting to improve, thanks to Rachel Carson, but as Colborn points out, "trends are not destiny." Just as Carson's work may have prevented the "silent spring" that she predicted, today's scientific research may enable us to avoid the remaining dangers of indiscriminate use of chemical pesticides.

In addition to bans on specific pesticides, several other landmark laws were passed in the wake of Silent Spring, their sponsors often crediting Carson with the impetus to bring about sweeping changes in environmental law and policy. The 1965 Water Quality Act attempted to specify acceptable levels of pollution in interstate waterways. The 1967 Air Quality Act took a regional approach to the regulation of air pollution such that emissions limitations were controlled by the states. The National Environmental Policy Act (NEPA) was passed in 1969, requiring all federal agencies to assess the environmental impact of their actions, which led directly to the formation of the Environmental Protection Agency (EPA) in 1970. That same year the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was passed, requiring all pesticide manufacturers to register their products with the EPA. Products that could not be applied or used with adequate levels of safety would not be registered. Also in 1970, Congress gave responsibility for enforceable standards to the federal government as part of the Clean Air Act. With the 1972 Clean Water Act, the federal government prohibited the emission of any pollutant into navigable water without a permit. If Silent Spring were the catalyst for these changes alone, Carson's legacy would be sealed — but such is not the case.

I believe Rachel Carson's most important impact was in neither science nor environmental law and policy. Her most lasting work was done in the minds of young women who read and admired her writing. She demonstrated that women could work in science and produce important results. Her work opened doors for later female science writers inspired to take up her torch. Her words struck a chord with her readers, especially young women. If she had not been so enamored with biology, Carson may well have been the 20th Century's most important feminist voice. Instead, she spoke for the entire planet.

Rachel Carson never committed the sin of anthropomorphism in her work, instead immersing herself and her reader in the mind of nature as seen through the eye of science. She took nature writing to a new level, culminating in the creation of a new genre, the ecological apocalypse, which has yet to fall out of favor among the book-buying public. She generated a paradigm shift in our attitude toward the planet and the chemicals we pour into our environment. She felt an obligation to help others see and understand, an obligation she met with tireless enthusiasm and incredible creativity. She helped us to see the world, more aware of all its beauties and wonders and the "strange and sometimes terrible intensity of the lives that are being lived about us."

The sum of Rachel Carson's achievements is a legacy without equal. And she did it entirely through her use of the written word. Writing was simply Rachel Carson's life-history strategy. She wrote to express her sense of wonder. Rachel Carson could no more avoid writing than Anguilla could avoid swimming upstream.