Banned

by Frederick Rowe Davis

  Despite Hueper’s refusal to directly link chlorinated hydrocarbons to cancer, Kleinfeld continued to press, citing considerable evidence that DDT was accumulating in the fat of people not directly exposed to it. Kleinfeld asked: “Would such an accumulation of DDT in the fat of the ordinary person, young or old, well or sick, possibly create some hazards?” Hueper replied: “I think on the basis of the evidence we have right now we cannot say. We have to wait, perhaps, 10 or 15 years to see whether such evidence may be forthcoming.”69 It is fair to say that no one in the U.S. was better positioned than Hueper to render an informed opinion on the possibility that chlorinated hydrocarbons might cause cancer, but as of January 1952, he believed that such a case would require ten to fifteen years of research. Historian Robert Proctor has suggested that the medical profession regarded Hueper as a maverick in his unrelenting effort to track down industrial carcinogens. More significant, Proctor noted that Hueper’s views had lost favor in the realms of science and politics. By the 1950s and 1960s, medical researchers regarded environmental carcinogenesis as rather out-of-date; researchers considered nonchemical factors, such as viruses and genetics, as more significant in the etiology of cancer. More important, according to Proctor, in the era of postwar conservatism, Hueper’s prolabor and perceived anti-industry stance of cleaning up the workplace and the environment garnered little support.70

  In 1948, Hueper became the founding director of the Environmental Cancer Section of the National Cancer Institute (NCI), the research arm of the PHS. Research Hueper had initiated before he achieved his position at the NCI resulted in his departure. Specifically, he accepted a consultancy at the Baltimore plant of the Mutual Chemical Company to investigate the link between chromium dust and lung cancer. The NCI funded Thomas Mancuso of the Ohio Health Department to study chromium dust at an Ohio plant. In 1951, Mancuso and Hueper jointly published a paper that confirmed elevated lung cancer rates at the chromium plant. When they attempted to publish another paper that suggested the possibility that the risk of cancer extended to the population outside chromium plants, the chief of the Industrial Hygiene Division at NCI ordered Hueper to remove his name from the paper. Hueper acquiesced but complained to the surgeon general, who shut down all of Hueper’s activities outside the laboratory. Moreover, Hueper had to “discontinue work on chromium, end his field work, and cease all contact with industry and with state and local health agencies.”71 Environmental scientists Benjamin Ross and Steven Amter have suggested that the strictures placed on Hueper were the result of express or implied threats against other PHS programs (by the 1950s, Clarence Cannon, who in 1937 had redirected pesticide research from the FDA to the Industrial Hygiene Division, had become chairman of the House Appropriations Committee). When Hueper resumed research on chromium two years later, his superiors shut down his program after less than six months.72 Frustrated by political pressures on his research and advocacy, Hueper resigned from his prominent position in cancer research in 1964.

  Despite the professional challenges he faced throughout his career, Hueper provided critically important insights that would continue to resonate with legislative and regulatory efforts to control additives to foods.73 When Miller asked him for his suggestions regarding the use of chemicals in foods, Hueper responded with a prescient statement that anticipated the direction of legislation and regulation: “I would feel that the uncontrolled use of any known or suspected agent with carcinogenic properties is not advisable, and that certain control measures should be taken.”74 On further examination, Hueper noted that the general population was probably exposed to materials in food more than through any other product, including cosmetics and medicines. On the basis of that view, he recommended toxicity testing for chemical additives to foods even in small doses.75 Although the size of the committee was somewhat diminished on the day of Hueper’s testimony, due to illness and other committee meetings, a few key policy makers took his recommendations to heart as they contemplated novel regulation.

  Throughout the hearings, testimony kept returning to DDT and its potential toxicity for humans. Even the small sample of expert testimonies analyzed to this point reveals a wide range of views regarding risks associated with novel insecticides. Entomologists, toxicologists, and farmers presented widely divergent views with respect to DDT from fairly harmless, when used properly, to extremely toxic and becoming more so as the chemical accumulated within organisms. It has also become clear that the primary link between government regulators and end users was the USDA. Within the USDA, it was the Bureau of Entomology and Plant Quarantine, based in Orlando, Florida, that was responsible for the analysis of the new chemical insecticides. On May 22, 1951, the committee heard the testimony of Fred C. Bishopp, assistant chief of the BEPQ in charge of research. Two other scientists, Edward F. Knipling and W. C. Shaw, accompanied Bishopp to offer additional insights and clarifications. From the outset, Bishopp acknowledged concerns regarding the release of new and highly poisonous insecticides for public use, but like other entomologists, he suggested that they were comparatively safer than the insecticides they replaced: “Some people have been apprehensive of the release of new and highly poisonous insecticides for public use. Actually, many of these materials are no more poisonous than nicotine, arsenicals, and sodium fluoride that have been used as insecticides for many years. The newer materials—including DDT, benzene hexachloride (BHC), toxaphene, and chlordane—have, to a considerable extent, replaced these older insecticides and are used on a much larger scale. Nevertheless, probably fewer accidental deaths from acute poisoning by the new materials occur today than were caused by the older insecticides in the past.”76 Bishopp argued that new insecticides underwent greater scrutiny than in the past before a manufacturer would release the chemical to the public and before it would be registered by state or federal agencies. Despite field and laboratory studies that concerned formulations, mode of action, effectiveness under varying ecological conditions, toxicity to plants and animals, and spray residues, Bishopp acknowledged that such analysis did not necessarily cover all fields of public interest before the product became available for public use. Bishopp was confident that additional research would lead to the development of more efficient pesticides that were essential to achieve crop production requirements necessitated by the “national emergency.”

  When he turned to specific insecticides, Bishopp offered a clear statement of the potential risks of DDT: “Although certain information on new insecticides is lacking, one of the most pressing problems is the dissemination of the authentic available facts to the public. It must become more widely known that DDT and related compounds, although of relatively low acute toxicity to man, are persistent and therefore residues on crops must be reduced to a minimum.”77 With this statement, Bishopp addressed one of the constant sources of confusion regarding the toxicity of DDT; namely, that the persistence of the chemical within organisms had the potential to increase its toxicity over time. What Bishopp referred to as the “[organic] phosphate insecticides,” like parathion and HETP, were quite different in that they were highly poisonous, but the residues rapidly degraded. It was the organic phosphates, he noted, that were responsible for most of the serious accidental insecticide poisonings that occurred in the previous two years, although he attributed them to workers failing to use respirators and protective clothing.78 Thus, Bishopp characterized the trade-offs between DDT and other chlorinated hydrocarbons and the organophosphates. DDT presented relatively low toxicity, but it persisted and accumulated in the environment. Organic phosphates with high toxicity posed serious risks to operators, but given their rapid rate of decomposition posed minor risk to the food supply.

  Like other experts, Bishopp testified to the extraordinary gains in food production that resulted from the widespread application of chemical insecticides, or rather, he suggested the abysmal state of crops in the absence of insecticides.79 He also cited several specific cases in which DDT had significantly controlled an insect outbreak. A po
tential outbreak of velvetbean caterpillar in 1946 provided one example; Bishopp noted that prompt application of several insecticides lessened loses to several crops, but DDT produced faster action: “Dust mixtures containing from 2.5 to 5 percent DDT applied at rates of 12 to 20 pounds per acre gave faster action against the caterpillars than cryolite or calcium arsenate and resulted in generally higher control.”80 In another case, insect control promoted tomato yields: “In California, during 1945, approximately 66,500 acres of tomatoes were treated by airplane with 10 percent DDT, at 65 pounds per acre, in the dust form, for the control of the tomato-fruit worm, using 4,322,500 pounds of a DDT insecticide.”81 Certainly these two cases bolstered Bishopp’s case that DDT provided effective control against insect outbreaks. And yet it is remarkable that Bishopp, the head of research at USDA’s BEPQ, recounted spray campaigns that applied DDT at 12 to 20 pounds per acre in the first example and 65 pounds per acre in the second. Recall from chapter 2 that the FWS and the PHS tested for potential wildlife effects using concentrations of DDT at 5 pounds per acre or less (and typically less than 2 pounds per acre and often half of 1 pound per acre). Bishopp’s statement signaled profound disparities between recommended rates of application and actual rates. Even if the high rates of application were somehow justified, the sheer volume of DDT applied (4.3 million pounds on tomatoes in California alone) boggles the mind. Unfortunately, these are the only two instances in which Bishopp cited the actual application rate of DDT. In numerous other examples, he noted the monetary savings in millions of dollars or dollars of cattle per pennies of DDT.

  In addition to asserting the considerable benefit of DDT to meeting the nation’s growing demand for food production, Bishopp also noted the demonstrated benefit of the chemical in the fight against infectious diseases, namely insect-borne disease: “The development of DDT and other new insecticides for controlling disease-carrying insects represents one of the most important advances in medical history. The control of malaria, typhus, encephalitis, dengue fever, yellow fever, filariasis, and other diseases has improved the health of man and increased his life expectancy throughout the world.”82 Bishopp noted that malaria, which he called the “most important disease of man in the world,” could be effectively and economically controlled by spraying residual DDT, BHC, or chlordane in homes. Statistics from the World Health Organization supported this claim, and Bishopp concluded by noting, “The almost complete elimination of malaria from the U.S. was hastened by the spraying of 800,000 homes with DDT during 1950 by the U.S.P.H.S. and the State Health departments.”83 Bishopp could enumerate the benefits of DDT to agriculture and public health at great length, and it is clear that such benefits were profound.

  And yet Kleinfeld intended to clarify the risks of DDT as well. To that end, Kleinfeld focused on USDA’s recommendations regarding DDT residues in milk and cited the following paragraph from a 1945 paper in Science: “These preliminary observations prove that with continued oral administration of DDT to goats and rats, there is eliminated in their milk a toxic substance which produces symptoms indistinguishable from DDT intoxication. The data strongly suggest the need for more intensive research on the toxicity of milk from dairy cows ingesting DDT residues either from sprayed or dusted forage plants or from licking themselves after being sprayed or dusted with this insecticide.”84 This statement contradicted one of Bishopp’s statements, and Kleinfeld asked Bishopp whether it was safe to assume that DDT applied as a dust or wettable powder in water would not be absorbed by cattle. In responding, Bishopp noted that the Science paper was based on ingestion or more specifically experimental feeding and that the USDA recommendations noted that there was a hazard in connection with feeding crops that carried DDT to dairy stock in any considerable amount. When pressed, Bishopp elaborated on this point: “There was no reason to assume that the spraying of barns, that is, putting down a persistent residue, on the walls and ceiling or spraying the cattle with the wettable powder, which is really just technical DDT, should result in any contamination of the milk.”85

  Kleinfeld next asked Bishopp to expand on his statement that the Oklahoma Experimental Station had found that dairy cows sprayed with DDT excreted the chemical in their milk. In this case and many others, Bishopp deflected the question to Edward F. Knipling, also of the BEPQ in Orlando (see chapter 2). Knipling explained that the work in Oklahoma involved what he called “excessive doses of DDT,” which greatly exceeded the recommended doses for insect control on dairy cattle. The BEPQ replicated the studies using DDT as recommended and generally used. They reported the results of this research at the Texas Entomological Society meeting in February 1947, and Agricultural Chemicals, the trade journal of the National Agricultural Chemicals Association, reviewed the paper in its April 1947 issue. Knipling noted that the research at the Texas Experimental Station did not merit an official release, given that the public consumption of DDT would not exceed 0.25 ppm.86

  Kleinfeld next turned to the USDA’s official publication, “The New Insecticides for Controlling External Parasites of Livestock” dated April 1949, which recommended against DDT application to dairy animals producing milk for human consumption due to the appearance of the chemical in milk at potentially hazardous levels as judged by the FDA. Nor should DDT be used in places where milk could be contaminated by the chemical.87 When Kleinfeld asked Bishopp if he believed the statement to be a sufficient and direct recommendation to dairy farmers not to use DDT as described in the statement, Bishopp deflected the answer to his colleague Knipling, noting that the USDA issued more direct statements to farmers within circulars. At this point, Miller demanded clarification: “Well, I took it from your testimony this morning that you think there is little or no harm that comes from the use of DDT around dairy barns. Am I correct in that assumption?”88 Bishopp acknowledged that he ought to qualify his answer. Again, Miller pressed him to be clear, and Bishopp responded: “We are definitely recommending against the use of DDT in dairy barns and on dairy cattle, dairy plants, milk houses, and all such places as that.”89 This statement addressed Miller’s concern that Bishopp on behalf of the USDA was defending the use of DDT in dairy barns, but Knipling seemed to feel that the issue still required clarification, and his comments shed light on a fundamental fracture in the history of toxicological regulation.90 Namely, the USDA could and did conduct research on potential pathways for contamination of milk and other agricultural products, but it was the responsibility of the FDA to determine the levels of contamination that would be hazardous to humans.91

  The cloud of uncertainty surrounding the toxicity of DDT and other chlorinated hydrocarbons did not extend to other chemical insecticides, for example, the organophosphates. Kleinfeld examined Bishopp on the use and toxicity of parathion. Bishopp rejected the notion that the chemical was widely used, noting that its use was more or less restricted to certain extensive crops, such as wheat, and specific infestations, including green bugs and fruit insects. Typically, the USDA recommended the use of parathion only in cases where less hazardous chemicals failed to control insects. Kleinfeld sought to establish on the record that parathion was extremely toxic so he pressed Bishopp with a series of questions regarding the toxicity of the chemical.92 Despite recognizing the risks, including eight deaths and forty-eight cases of severe toxemia, Bishopp admitted that the USDA had not recommended against the use of parathion on fruits.

  When Kleinfeld asked Bishopp to provide a safe residue level for any one item of the typical American diet for parathion, Bishopp initially deflected the question to the FDA, but Kleinfeld persisted in soliciting his opinion. Bishopp replied that he believed the FDA published a statement that 2 ppm may be safe, but that he felt that level was a bit high, noting that toxicologists pointed out that parathion metabolized readily.93 Even in the case of parathion, one of the most toxic insecticides ever to reach general use, Bishopp noted that its toxicity could be mitigated by its quick rate of metabolism. Kleinfeld cited a paper, “Absorption of DDT and Parathion by Fr
uits,” presented at the 1949 meeting of the American Chemical Society that found parathion in the peel but not the pulp of harvested oranges, lemons, and grapefruit. Based on the weight of the peel, 3 to 5 ppm of parathion were found in the peel of Valencia oranges six months after treatment with standard dosage. Bishopp noted that Valencia oranges have “pretty thick skins,” but Kleinfeld countered by asking whether orange peel was sometimes candied and also used in animal feed. Bishopp acknowledged both potential pathways of exposure but argued that the parathion was pretty largely destroyed in those products between harvesting, processing, and consumption. Kleinfeld again pointed out that parathion was present in quantities of 3 to 5 ppm up to six months after treatment, which Bishopp acknowledged was a considerable amount of time. Despite Kleinfeld’s pointed questions, Bishopp’s testimony did little to clarify for the committee whether parathion actually posed risks to consumers even as Bishopp recognized the chemical as one of the most toxic in use with a safe residue level of 2 ppm (or less, in his opinion).