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Spotting Pseudoscience

DDT: The rise and fall of a "miracle" chemical

by Alister R. Olson, Michael P. Clough, and Benjamin C. Herman

This story highlights three characteristics of science misinformation and disinformation efforts: attacks on legitimate scientists, neglect of refuting information, and the perception that an idea threatens one’s worldview. See Features of Science Misinformation/Disinformation Efforts: Understand how to detect false information for more information regarding these tactics.

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A Letter to the Boston Herald

The mosquito control plane flew over our small town last summer. Since we live close to the marshes, we were treated to several lethal doses as the pilot crisscrossed our place. … The “harmless” shower hath killed seven of our lovely songbirds outright. We picked up three dead bodies the next morning right by the door. They were birds that had lived close to us, trusted us, and built their nests in our trees year after year. The next day, they were scattered around the bird bath. … On the following day one robin dropped suddenly from a branch in our woods. We were too heartsick to hunt for other corpses. All of these birds died horribly, and in the same way. Their bills were gaping open, and their splayed claws were drawn up to their breasts in agony. … Air spraying where it is not needed or wanted is inhuman, undemocratic, and probably unconstitutional. For those of us who stand helplessly on the tortured earth, it is intolerable.

                                                                                                -Olga Owens Huckins, 1958 [1]

 

A “Miracle” Chemical is Developed

In 1873, a graduate student at the University of Strasbourg named Othmar Zeidler published work describing the synthesis of a white powder from the condensation between trichloroacetaldehyde and chlorobenzene [2] [3]. The chemical, dichlorodiphenyltrichloroethane (Figure 1), contributed to Zeidler’s dissertation, but otherwise brought him little recognition during his lifetime. However, by the 1930s, scientists had determined that compounds with similar structure as Zeidler’s were effective pesticides. The Swiss Chemist Paul Müller was aware of that fact, and in 1939, he determined that dichlorodiphenyltrichloroethane—later called DDT—was particularly powerful for killing a range of insects [2].

           

Müller’s recognition of the insecticidal properties of DDT occurred only a few weeks after Nazi Germany had begun their invasion of Poland, marking the beginning of World War II. As geopolitical events spiraled out of control and the United States was dragged into the war, the dangers that insects would pose to their troops was soon recognized. Typhus, which is spread by lice, killed 20-30 million people in Eastern Europe after World War I, and outbreaks had ravaged many armies throughout history [4]. Even worse, some experts estimated that 50% of troops could be afflicted by mosquito-borne malaria in the first mosquito season alone [5].

 

Facing such dire prospects, the United States began rapidly testing every chemical possible for insecticidal properties. Promising chemicals were applied to clothing and taped to the arms and legs of human test subjects to assess skin irritation [5]. Chemicals that advanced beyond those tests were applied to men who had been infected with lice, and were then confined to a dormitory for up to ten weeks to determine longevity of the insecticides [5]. Scientists recognized that the testing was inadequate, but the urgency of the war efforts necessitated that careful study be sacrificed for rapid development. Pyrethrum powder was determined to be effective at killing lice, and the chemical was briefly adopted for use by American soldiers until realizing the flowers from which it was derived were too difficult to acquire during the war.

While researchers were again scrambling to find a suitable insecticide in 1942, J. R. Geigy A. G.—the Swiss company that employed Paul Müller—gave the United States a sample of DDT [6]. DDT testing, which again was dramatically accelerated due to the urgency of the war, revealed that the chemical was incredibly potent, long-lived, killed a range of pests, and could be relatively easily produced. DDT was adopted by the American armed forces in September of 1943, less than a year after the first samples were received, and production was dramatically increased [5]. That winter, DDT was utilized in a groundbreaking effort to defeat a typhus epidemic in Naples [7] [5].

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Figure 1. The molecular structure of DDT.

Nature of science connections

Scientists have wrestled with the ethics of their investigations as long as research has been conducted. Many studies—particularly those conducted during wartime—lacked adequate safeguards for subjects, and resulted in significant harm to them. Particularly egregious research, such as the Tuskegee Syphilis Study, led to legislation in the United States that required scientists to gain approval for studies involving humans from an Institutional Review Board (IRB). While IRB approval and other measures have provided protections for humans and other living subjects, scientists still routinely have to struggle with ethical decisions related to their research.

DDT quickly became one of the symbols of American technological power during World War II, and was prominently featured in numerous wartime film clips. Paul Müller went on to win the Nobel Prize in 1948 for his work with the insecticide [8] [9] [10]. Few people at the time could have guessed that DDT would be gone from the American market within 30 years.

 

Rachel Carson

Rachel Carson was born in Springdale, Pennsylvania, in 1910 [11], and grew up on an idyllic farm exploring the outdoors with her mother [12]. Carson was a talented writer from a young age, and she eventually entered the Pennsylvania College for Women as an English major in 1925 [12]. However, inspired by one of her teachers, Carson switched to a biology major during her sophomore year—a bold choice given the challenges that women faced in the sciences during the era [11]. Rachel was a bright and dedicated student, leading to a fellowship at Woods Hole Marine Biological Laboratory following graduation, and eventually to completion of a master’s degree in zoology from Johns Hopkins University in 1932 [12]. Carson began work on a doctoral degree as well, but the Great Depression forced her family to move in with her, and then her father’s death in 1935 left her responsible for financially supporting the family [11] [12].

 

Carson left her doctoral program and was hired by the Bureau of Fisheries as a junior aquatic biologist, although her work would not be as a researcher, but rather as a writer [11] [13] [12] [14]. The skill of the young biologist’s writing was quickly recognized, and she was even able to publish some of her own work in sources such as the Atlantic Monthly [11] [12]. In November 1941, Carson published a book called Under the Sea-Wind that unfortunately failed to achieve much financial success, likely due to being overshadowed by Pearl Harbor occurring less than one month after being released. Despite the setback, Carson was still thriving at her job with the United States Fish and Wildlife Service (USFWS), combining her strong background in biology with her exquisite writing to edit informational material for the public and scientific articles [11]. As a result of her position, Carson received access to a vast amount of USFWS research, including concerning studies examining the safety of DDT.

 

Insufficient Testing, Lack of Regulation, and Growing Concern

Unsettling research related to DDT had emerged early in its safety testing. In 1943, researchers at the FDA identified three potential hazards related to DDT that demanded further research: (1) DDT in solution was readily absorbed through the skin causing tremors, paralysis, and even death in rabbits; (2) chronic exposure to DDT produced a wide range of organ damage in test animals; and (3) while inhalation of DDT had little effect on some animals (e.g., dogs), it killed others, such as mice [5]. Wartime needs overrode uncertainties related to safety, but widespread use of the chemical led to increased concerns about it.

 

In 1944-1945 alone, reports included: (1) widespread death of fish, crabs, and insects due to DDT use in the Pacific; (2) recognition that DDT resembled known carcinogens in appearance and effect; (3) fish mortality from low dose DDT application, and significant declines in bird populations with higher doses; and (4) harm to some crops, beneficial insects, and animals [5]. Some scientists during this period even warned that heavy use of DDT could result in “biological deserts” that would be “devoid of life” [5].

 

The emerging reports and research led the army and United States Public Health Service to enact regulations in April 1945 that severely limited domestic aerial spraying of DDT [5]. Such restrictions may seem incongruent with the wide use of the spray at this time by the U.S. armed forces to protect soldiers overseas, but the press release announcing the 1945 regulations addressed the apparent inconsistency:

 

… DDT distributed over the countryside not only wipes out malaria carrying mosquitoes but also may kill other insects, many of which are beneficial. Much still must be learned about the effect of DDT on the balance of nature important to agriculture and wild life before general outdoor application of DDT can be safely employed in this country. It may be necessary to ignore these considerations in war areas where the health of our fighting men is at stake, but in the United States such considerations cannot be neglected. U.S. Army, & U.S. Public Health Service, p. 284 [15]

 

However, the U.S. Army and U.S. Public Health Service only controlled DDT use in the United States as long as military need exceeded the amount of pesticide being produced. When manufacturers managed to exceed wartime need in the latter half of 1945, the prospect of selling DDT to civilians for domestic use loomed large. Despite the concerns of prominent scientists such as Clarence Cottam of the USFWS, who asked for further testing of the environmental impacts of DDT before allowing the public to buy it, the War Production Board allowed the public to begin purchasing surplus stock of the pesticide in August 1945 [5]. The U.S. Army and U.S. Public Health Service regulations did not apply to the public, and beyond some limited labeling requirements, the sale and use of DDT therefore became virtually unchecked by the United States government.

 

Production of DDT rapidly grew over the subsequent years, and the military technology that had been rushed through safety testing due to extraordinary wartime needs soon became the top pesticide for civilian use in the United States. In 1959 alone, Americans used 79 million pounds of DDT [8]. Government officials and agencies at various levels were also responsible for a considerable amount of DDT use, as they engaged in large-scale efforts to eradicate pests such as the gypsy moth, beetles carrying Dutch elm disease, and tent caterpillars [14]. For many, DDT was seen as nothing short of a miracle.

 

Silent Spring

Even as sales of DDT were skyrocketing, concerns about the chemical persisted. Publications highlighting problematic issues related to pesticides continued to cross the desk of Carson, who in 1949 had become editor in chief of USFWS publications. Additionally, many popular news media articles being published about DDT highlighted concerns about its use and safety. In reaction to the increasing concerns about DDT, Paul Mayfield, then president of the National Agricultural Chemicals Association, complained in 1954 about propaganda, misinformation, exaggeration, and “pseudoscientific double talk” that was harming the pesticide industry. He wrote:

 

Only 10 years ago DDT was being hailed as a wonder chemical to rank with the drugs which are eliminating such diseases as malaria and typhus. The aerosol bomb was a symbol of the American Army to many of the people of North Africa and Italy. … But today we find the other side of public opinion being aroused while the favorable aspects are neglected. The Sunday supplements are being loaded with allegations that DDT and other “poisonous chemicals” cause all manner of human ills. Mayfield, p. 176 [16]

 

News coverage was actually predominantly positive in the early 1950s, although the frequency of negative articles significantly increased as the decade wore on [17]. One cause of that trend was backlash to aerial spraying campaigns—particularly by landowners in the northeast. For example, the United States Department of Agriculture sprayed millions of acres of land in an attempt to extirpate the invasive gypsy moth—a campaign which many residents vehemently opposed, and eventually even fought in court [17]. Olga Huckins’ letter to the Boston Herald regarding aerial spraying of DDT (the introduction to this story is an excerpt from that letter) was also sent to her friend, Rachel Carson, along with a request for help to end the spraying [14].

 

When Carson received Huckins’ letter in 1958, she was in a very different position than she had been for much of her life. In 1951, she had published an extremely popular book called The Sea Around Us, which enabled her to retire from USFWS the next year, and move to a house in Maine [12]. Carson had been bothered for years by the DDT research she had read [18], and as early as 1945 she had even considered writing an article about the effects of the chemical on the environment [12]. However, Huckins’ letter was the catalyst that finally inspired her to write a book about the topic [19].

Carson’s connections to the USFWS and name recognition as a best-selling author helped her reach out to scientists from around the world to learn more about the effects of pesticides [12]. Undeterred by a diagnosis of breast cancer in 1960, Carson pressed on and in 1961 she published her book, titled Silent Spring. Carson’s book stressed the interdependence of the organisms on our planet, and the dangerous, often unforeseen consequences of altering the balance of those relationships in misguided attempts to control nature. Broad-spectrum pesticides, such as DDT, were identified as being particularly concerning given that they killed indiscriminately, affecting organisms in the land, air, and water. Carson also warned that the chronic exposure and ubiquitous presence of many of the chemicals that are rushed to market pose health risks that are particularly pernicious given the difficulty in identifying their cumulative effects that only become apparent over time. While the utility of pesticides was recognized in the book, Carson argued that people should have a right to live in a world where they are not forced to be exposed to chemicals that we know little about.

Nature of science connections

Scientists often disagree with one another due to—among many other factors—differences in prior knowledge, values, and goals. However, not all scientists’ opinions should be considered equal by the public. Scientists develop very narrow, but incredibly deep knowledge in their specific area of study. Even famous scientists therefore should be considered experts only within their respective areas of study. In this case, economic entomologists had been researching DDT for years, but primarily in the context of food supply issues related to pest control. Issues related to broader environmental impacts of the pesticide therefore generally were better understood by ecologists and other relevant biologists, who largely supported Carson. However, given the many idiosyncratic factors which can affect individual opinions, even among legitimate experts, the public is best served by referring to position statements produced by relevant professional organizations that represent the consensus of the field.

Silent Spring was an instant success. The mixture of fictional, anecdotal, historical, and research-based accounts of technological harm in the book resonated with an uneasy public that had been primed by a tainted cranberry scare, news of severe birth defects caused by thalidomide, the ever-present specter of a nuclear holocaust, and the St. Louis baby tooth survey that demonstrated that radioactive strontium-90 levels had increased dramatically in the baby teeth of children due to nuclear weapons testing.

Recognizing the reaction to Carson’s work, John F. Kennedy announced that he would have his President’s Science Advisory Committee (PSAC) investigate the issue of DDT [20] [21]. The response from many others, including some scientists, people from the pesticide industry, and other government officials, was far more hostile. Carson was accused of being—among many other things—a communist, antibusiness, subversive, and a “hysterical” female [11] [13]. Many critics chose to describe apocalyptic scenarios of disease and famine that would result from Carson’s supposedly anti-technology views [8] [22] [23]. A review of Carson’s book in Science described her work as “unbalanced” and “emotional,” while an article in Time similarly derided Silent Spring as “patently unsound” and an “emotional outburst” [23].

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Red Flag  |  Attacks on legitimate scientists

While Carson was technically not a practicing scientist, she was a prominent figure whose ideas influenced scientists’ discourse and research in numerous fields. Rather than contesting Carson’s points, critics often resorted to personal attacks, which is a classic warning sign of misinformation/disinformation.

The reaction of scientists often varied by discipline, with oceanographers and biologists generally supporting Carson, but many food scientists, economic entomologists, and chemists reacting negatively [12] [21]. Despite the attacks and divided responses from the scientific community, public support for Carson grew—particularly after a CBS documentary allowed her to discuss the issue of DDT to the public on television in 1963 [20] [18] [12] [14].

Question 1

Personal attacks are a common feature of misinformation/disinformation efforts. How does attacking individuals assist in spreading disinformation/misinformation?

On April 14, 1964, Rachel Carson succumbed to breast cancer [20] [12]. However, the impact of her work was just beginning to be felt. Within a month of Carson’s death, the PSAC released a report that aimed to represent consensus views from relevant fields of study [21]. The experts on the panel noted the legitimate arguments both for and against DDT, and that significant uncertainties still needed to be addressed. However, they argued that wildlife were clearly being harmed by the pesticide, adverse effects of the chemical were likely more prevalent than what was reported, and that while pesticides were important, their use should be restrained [21]. Overall, the report supported Silent Spring and the concerns that Carson had raised [18]. Usage of DDT in the United States, which had been declining since its peak in 1959, dropped precipitously in the ensuing years (Figure 2).

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Figure 2. DDT usage in the United States by year (1950-1973) [8].

Just as public and consumer sentiment about DDT were shifting, dramatic changes were also occurring within the scientific community regarding the pesticide. Economic entomologists had dominated research on DDT in its early years, and they focused on the role of the pesticide in securing a steady supply of inexpensive food for people [21]. Other researchers emphasized the immediate, and considerable public health benefits of DDT use. Both of those aspects of pesticide use are legitimate and important to consider, and some authors have argued that by 1970, DDT had already saved up to 500 million people from malaria [14]. Carson was cognizant of those benefits, but she emphasized the environmental effects of DDT and the dangers of chronic exposure, because she argued that those aspects of the scholarly debate had not been adequately presented to the public.

Following publication of Silent Spring, research from a diverse range of scientific fields, such as ecology, began to take a more prominent role, and shifted the focus of DDT studies from agricultural impacts to environmental and human health [8]. The body of accepted knowledge about the pesticide also therefore changed, as emerging research converged on the damaging environmental impacts of DDT that Carson had warned the public of [8]. By 1969, several states had banned DDT [8]. In 1970, the Environmental Protection Agency (EPA) was formed—the creation of which has been directly linked to the publication of Silent Spring [8] [24]. The EPA rapidly grew in size and power, and provided the government with a mechanism for meaningfully regulating pesticides which it had lacked since the end of World War II. Given the attention that DDT had received, the pesticide became a priority for the EPA, and in 1972, the agency announced that the chemical would be banned for domestic use effective the following year [13] [8] [21] [9].

Nature of science connections

Science not only affects society through the technologies that develop from its knowledge about the natural world, but also in the ways it impacts our thinking and actions. Society also affects the direction of science, particularly when a pressing societal issue demands greater knowledge about nature.

Question 2

A strength of science is how scientists can reexamine prior knowledge and, if necessary, modify or replace it. But how can this self-correcting process be used by those seeking to sow misinformation/disinformation?

Renewed Attacks on Carson and DDT Today

Despite being banned in the United States, DDT is still used today in many countries. However, numerous studies have linked the pesticide to an array of health effects, including cancer, diabetes, and neurodevelopmental effects [25]. More recent research has also identified potential epigenetic pathways for DDT to produce transgenerational inheritance of a number of diseases [26]. In Eskenazi et al.’s review of epidemiological studies from 2003-2008, the authors readily recognized the devastating effects of malaria, and therefore the seriousness of DDT regulation, and that more research is needed regarding many of the specific health effects of DDT. Nonetheless, Eskenazi et al. concluded that:

 

The recent literature shows a growing body of evidence that exposure to DDT and its breakdown product DDE may be associated with adverse health outcomes such as breast cancer, diabetes, decreased semen quality, spontaneous abortion, and impaired neurodevelopment in children. Eskenazi, et al, p. 1,359 [25]

 

In 2006, the World Health Organization (WHO) brought DDT back for indoor spraying as part of a rotation of insecticides to help combat malaria [27]. In deciding to do so, the WHO acknowledged the many benefits of DDT, and argued that the health concerns related to the pesticide would not outweigh the benefits in malaria prone areas as long as the chemical was carefully utilized in the manner they described [27]. However, the organization also stressed its support for the Stockholm Convention, a United Nations’ treaty that seeks to curtail the use of organic pollutants that persist in the environment long after they are first applied. The first twelve chemicals addressed by the treaty—dubbed the “dirty dozen”—included DDT, which the treaty emphasized should be replaced with an acceptable alternative as soon as possible. The WHO’s position statement therefore reflects the complexity of carefully weighing the pros and cons of the pesticide in certain situations.

Such analysis can be contrasted with some contemporary advocates of DDT who portray the pesticide as a “silver bullet” that has been unfairly removed from public use. One analyst with the Heartland Institute argued for agricultural use of DDT and stated that “[g]overnments should consequently lift the bans on DDT and other pesticides” [28]. Such positions ignore the extensive body of research documenting increasing resistance to DDT among various insect populations [10], reduced crop yields in many cases due to the broad-spectrum insecticide killing beneficial insects, and the aforementioned impacts on human health and the environment.

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Red Flag  |  Neglect of refuting information

Failure to recognize the well-established body of research related to the hazards of DDT when addressing the pesticide can produce distorted views of the science related to its safety. This tactic is often a sign of pseudoscience.

In some cases, individuals have gone as far as to suggest that Rachel Carson is therefore responsible for millions of deaths due to malaria:

 

…today millions of people around the world suffer the painful and often deadly effects of malaria because one person sounded a false alarm. That person is Rachel Carson, author of the 1962 best selling book Silent Spring. [29]

Others have attempted to discredit Silent Spring via highly selective attacks on details from the book to try to undermine it—often in a misleading and inaccurate manner [10]. Such attacks have seen a resurgence in recent years as Carson has become ensnared in broader debates regarding environmental regulation, the EPA, and climate change [10]. While Carson is largely responsible for the modern environmental movement and formation of the EPA, she clearly stated that she did not broadly oppose pesticides or their use [19] [12] [14], and that she was not particularly interested in politics [11]. Despite those facts, the soft spoken science writer has come to be represented by some people as a partisan environmental extremist whose achievements are seen as a threat to their worldview.

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Red Flag  |  Science idea perceived as threatening a worldview

Note how many critics of Carson now try to attack her because of the implications of her scientific ideas on their ideological positions. For example, the interconnectedness of all humans with the entire ecosystem can be seen as a justification for regulations, which is in turn seen as a threat by some people who oppose such actions. Recognizing how some scientific ideas may be perceived by certain individuals as conflicting with their worldviews is an important step in identifying potential sources of pseudoscience.

Question 3

How are complex societal issues easy prey for those sowing misinformation/ disinformation?

The Complexity of Socioscientific Decision-Making

At first glance, Carson’s story seems to have parallels with that of the disgraced British physician Andrew Wakefield (see Vaccine hesitancy: Placing Everyone at Risk). Both people went directly to the public to alert them of dangers related to technology, they were subsequently accused of advancing pseudoscientific arguments, and both have suffered many personal attacks. However, crucial differences exist between the two stories that explain why the outcome was so different for Carson and Wakefield. For example, Wakefield was a practicing researcher who skirted the science vetting process in bringing the results of his own research directly to the public—conclusions that were contrary to existing research and surprising to the majority of the scientific community.

 

Carson, on the other hand, drew upon a wide base of existing vetted scientific research from nearly 20 years of studies to bring that work to the attention of the public. Wakefield’s conflict with the scientific community therefore centered around the validity of the claims that he was making, whereas the divided response from scientists towards Carson was the result of numerous factors, including disagreement on what values should be foregrounded in the scientific debate, sexism, and an increase in research by those who looked beyond economic benefits of DDT. In both cases, scientific debate about the respective issues presented significant challenges for the public to evaluate the arguments being put forth. However, in both cases, expert, consensus opinion was key to making the best possible choice. In the case of DDT, that consensus opinion was particularly difficult to discern, given that members of the public had to recognize that experts who had traditionally studied certain aspects of the pesticide (e.g., economic and food supply issues) were not necessarily the experts who could best address the environmental and health impacts of the chemical.

Question 4

Misinformation/disinformation is at times difficult to determine. Given this difficulty, why is setting aside personal emotions and ideological preference all the more important for making sound personal and societal decisions?

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References

[1] Huckins, O. (1958). [Letter to the Boston Herald]. Beinecke Rare Book and Manuscript Library. (Series I. Writings. SILENT SPRING. Post-publication material. Related correspondence, Box 84, Folder 1473). https://collections.library.yale.edu/catalog/2026498

[2] Metcalf, R. L. (1973). A century of DDT. Journal of Agriculture and Food Chemistry, 21(4), 511-519.

[3] Zeidler, O. (1873). Beitrag zur kenntniss der verbindungen zwischen aldehyden und aromatischen kohlenwasserstoffen. [Doctoral dissertation, Universität Strassburg I. E.] https://books.google.com/books?id=qRRaAAAAcAAJ

[4] Gross, L. (1996). How Charles Nicolle of the Pasteur Institute discovered that epidemic typhus is transmitted by lice: Reminiscences from my years at the Pasteur Institute in Paris. Proc. Natl. Acad. Sci. USA, 93, 10539-10540.

[5] Russell III, E. P. (1999). The strange career of DDT: Experts, federal capacity, and environmentalism in World War II. Technology and Culture, 40(4), 770-796.

[6] Perkins, J. H. (1978). Reshaping technology in wartime: The effect of military goals on entomological research and insect-control practices. Technology and Culture, 19(2), 169-186.

[7] Jukes, T. H. (1969). DDT: The chemical of social change. Clinical Toxicology, 2(4), 359-370.

[8] Maguire, S., & Hardy, C. (2009). Discourse and deinstitutionalization: The decline of DDT. The Academy of Management Journal, 52(1), 148-178.

[9] Paull, J. (2007). Rachel Carson, a voice for organics – the first hundred years. Elementals, 86, 37-41

[10] Yang, J., Ward, M. D., & Kahr, B. (2017). Abuse of Rachel Carson and misuse of DDT science in the service of environmental deregulation. Angewandte Chemie, 129, 10158-10164.

[11] Allen, B. (2013). Rachel Carson revisited. The Hudson Review, 66(1), 183-188.

[12] Lear, L. J. (1993). Rachel Carson’s “Silent Spring.” Environmental History Review, 17(2), 23-48.

[13] Dreier, P. (2012). How Rachel Carson & Michael Harrington changed the world. Contexts, 11(2), 40-46.

[14] Watson, B. (2002). Sounding the alarm. Smithsonian, 33(6), 115-117.

[15] U.S. Army, & U.S. Public Health Service. (1945). Use of DDT for mosquito control in the United States. Journal of Economic Entomology, 38(2), 284.

[16] Mayfield, P. (1954). A sound future for…agricultural chemicals. Agricultural and Food Chemistry, 2(4), 172-176.

[17] Gunter, V. J., & Harris, C. K. (1998). Noisy winter: The DDT controversy in the years before Silent Spring. Rural Sociology, 63(2), 179-198.

[18] Lear, L. J. (1992). Bombshell in Beltsville: The USDA and the challenge of “Silent Spring.” Agricultural History, 66(2), 151-170.

[19] Carson, R. (2002). Silent spring. Houghton Mifflin Harcourt.

[20] Hazlett, M. (2004). ‘Woman vs Man vs Bugs’: Gender and popular ecology in early reactions to Silent Spring. Environmental History, 9(4), 701-729.

[21] Oreskes, N. (2004). Science and public policy: What’s proof got to do with it? Environmental Science & Policy, 7, 369-383.

[22] Murray, D. L., & Taylor, P. L. (2000). Claim no easy victories: Evaluating the pesticide industry’s global safe use campaign. World Development, 28(10), 1735-1749.

[23] Smith, M. B. (2001). “Silence, Miss Carson!” science, gender, and the reception of “Silent Spring.” Feminist Studies, 27(3), 733-752.

[24] Parks, P. (2017). Silent Spring, loud legacy: How elite media helped establish an environmentalist icon. Journalism & Mass Communication Quarterly, 94(4), 1215-1238.

[25] Eskenazi, B., Chevrier, J., Rosas, L. G., Anderson, H. A., Bornman, M. S., Bouwman, H., Chen, A., Cohn, B. A., de Jager, C., Henshel, D. S., Leipzig, F., Lorenz, E. C., Snedeker, S. M., & Stapleton, D. (2009). The Pine River Statement: Human health consequences of DDT use. Environmental Health Perspectives, 117(9), 1359-1367.

[26] Kabasenche, W. P., & Skinner, M. K. (2014). DDT, epigenetic harm, and transgenerational environmental justice. Environmental Health, 13(62). doi: 10.1186/1476-069X-13-62

[27] World Health Organization. (2011). The use of DDT in malaria vector control: WHO position statement. http://apps.who.int/iris/bitstream/handle/10665/69945/WHO_HTM_GMP_2011_eng.pdf

[28] Smith, T. (2014, July 29). Research & commentary: DDT bans. https://www.heartland.org/publications-resources/publications/research--commentary-ddt-bans

[29] Competitive Enterprise Institute. (2007, March 1). Rachel Carson’s dangerous legacy. SAFEChemicalPolicy.org. https://www.safechemicalpolicy.org/rachel-was-wrong/

 
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