Banned
Page 25
As convincing as I find these case studies, my argument is simpler. When it came to organophosphates, no one seriously argued that they were safer than chlorinated hydrocarbons like DDT—and in that group I include toxicologists, regulators, industry representatives, and environmental advocates. In fact, as I have shown, in statement after statement, nearly everyone who testified in the various pesticides hearings readily acknowledged that, with the exception of malathion, organophosphates posed greater risks to humans and wildlife. For a pesticide like parathion, scientists, regulators, and industry representatives all agreed that it posed risks at the minutest exposures levels, at one or two parts per million! And yet, as most experts also noted, organophosphates had one notable advantage over DDT and the chlorinated hydrocarbons: organophosphates broke down into relatively harmless components over the course of weeks or even days, whereas chlorinated hydrocarbons accumulated in ecosystems and the bodies of wildlife and humans.
In retrospect, Geiling’s advice to be mindful of an obligation to the public seems prescient as debates surrounding pesticides moved from the realm of science and policy to public discourse. Geiling offered his words of wisdom at a time when toxicologists were establishing an independent professional identity. With the publication of Silent Spring and subsequent publicity, including a nationally aired news program, the public discovered the risks of DDT and other synthetic insecticides as well as the science of toxicology. Rachel Carson’s unassuming yet forceful prose revealed hazards attendant with the indiscriminate use of DDT and other chlorinated hydrocarbons, but some of her most disturbing case studies involve organophosphates. Her case for curbing pesticide use applied to both chlorinated hydrocarbons and organophosphates. Silent Spring and the public outcry that followed inspired further study at the federal level, first by the PSAC and then the congressional Committee on Interagency Coordination. As in other hearings, few questioned the considerable benefits of pesticides, and most witnesses couched evaluations of risks in light of benefits, but most witnesses, including Carson herself, acknowledged the considerable dangers associated with organophosphates. A familiar cast of scientists from the USDA, the FDA, and the Tox Lab presented their findings regarding organophosphates, the no-effect level, and potentiation (which was most common among organophosphates). In an attempt to defend their safety record, several representatives of the chemical industry presented the multistage and multiyear process, involving literally thousands of chemicals, through which a company identified, tested, and marketed a new insecticide. With a sharper picture of toxicological risk presented in layman’s terms in Silent Spring and thoroughly analyzed by the PSAC and Congress, the pathway to further regulation appeared clear.
CHAPTER 7
Pesticides and Toxicology after the DDT Ban
In Silent Spring, Rachel Carson meticulously described a typology of chemical insecticides. Most commonly used insecticides fell into one of two groups: chlorinated hydrocarbons (or organochlorines) like DDT and dieldrin and organophosphates like malathion and parathion. Both groups of chemicals had implications for the health of humans, wildlife, and ecosystems. Carson revealed how DDT and other organochlorines bioaccumulated in the environment and biomagnified in organic systems, until reaching toxic levels in topline predators such as ospreys, brown pelicans, and of course bald eagles. Organophosphates did not typically bioaccumulate, but exposure to the potent nerve agents resulted in cholinesterase inhibition by disrupting the normal function of an enzyme that was critical to normal nerve function. Organophosphates could cause tremors, convulsions, and even death in wildlife and humans. In case after case, Carson cited organophosphate poisonings of farm workers and wildlife. As we saw in the previous chapter, numerous witnesses from a diversity of perspectives testified to the extreme toxicity of organophosphates before the PSAC and in congressional hearings.
Nevertheless, Americans in general, and legislators in particular, took a different message from Silent Spring, namely, that DDT was the most harmful insecticide for its effects on wildlife, particularly birds. Moreover, Americans and American legislators became concerned about environmental cancer. It would be naïve to suggest that Silent Spring was the only factor in raising concern regarding environmental cancer. Congressional hearings devoted to possible risks, including cancer associated with pesticides beginning in 1951, resulted in passage of the Miller Amendment and the Delaney Clause (see chapter 5). But Silent Spring certainly crystallized this concern in the minds of many Americans, along with worries about environmental contamination and wildlife effects. Against such a backdrop, the banning of DDT late in 1972 concluded one of the greatest success stories of the environmental movement. But if history teaches us anything, it is to be wary of simple stories. According to historian Thomas Dunlap, Silent Spring (and the public controversy in its aftermath) failed to effect significant changes in pesticide use and regulation in the short term.1 The USDA did curb its extensive spraying programs, but other government agencies and farmers continued to employ DDT. In the cases where DDT was discontinued, it was replaced with more toxic chemicals like the organophosphates. During the remainder of the 1960s, environmentalists went to court several times in an attempt to control or stop the use of DDT. The recently established Environmental Defense Fund (EDF) pursued litigation against various uses of chlorinated hydrocarbons on several fronts. In Michigan, the EDF entered litigation against spraying programs that utilized DDT and dieldrin against Dutch elm disease. EDF’s action against dieldrin was thrown out of the court of appeals by the judge, but by taking the case to the Michigan Supreme Court, EDF was able to delay the spraying campaign until the best time for spraying had passed. The case against DDT in Dutch elm disease control did not reach the courts, because each of fifty-six communities agreed to stop applying DDT. EDF next took up the fight against dieldrin in Wisconsin, where the courts were marginally more interested than those in Michigan. By the end of preliminary discussions, however, a judge had rejected the arguments of EDF’s lawyers, cut their presentation short, and allowed for dieldrin spraying to continue. Near the end of 1968, Wisconsin did allow an extended hearing on whether DDT could contaminate water. Dunlap has argued that the six months of this hearing saw a sea change in Americans’ trust in government and their willingness to support groups that questioned government policies. By the end of 1968, there was a groundswell of support for the EDF’s efforts against DDT and other chlorinated hydrocarbons.2
Neither the passage of the National Environmental Protection Act (1970) nor the establishment of the Environmental Protection Agency (EPA) in October 1970 ended the battle against DDT. The EPA inherited USDA’s authority and staff in pesticide regulation, and the newly formed federal agency became a target for litigation. EDF returned to court, bringing suit against the EPA in EDF v. Ruckleshaus (D.C. Circuit 1971), in which EDF sought review of the failure to cancel the registration of DDT and to stop its use during cancellation hearings. During the course of this case, EDF strengthened its argument sufficiently so that the EPA had to take significant action against DDT. The judge and two colleagues ordered William Ruckleshaus (EPA administrator) to end all uses of DDT immediately. Although complying initially, Ruckleshaus refused to suspend registrations after a sixty-day review. Instead, at the behest of the U.S. Court of Appeals, the EPA would hold hearings to determine whether DDT posed a threat to human health. After the initial hearings, Ruckelshaus acknowledged that evidence that DDT was carcinogenic in lab animals did not prove that DDT was threat to humans. Moreover, he believed that “a quick and total ban on DDT would force farmers to resort to highly toxic alternatives.”3 Nevertheless, in June 1972, after yet another lengthy hearing, Ruckleshaus banned the remaining uses of DDT on crops. He did, however, allow it to be used in cases of urgent public health, such as emergency quarantine. He also allowed for it to be manufactured for export. At the same time, EPA suspended most uses of dieldrin, but it took more than two years before the agency announced a ban on the manufacture of dieldri
n and aldrin.4 More than a decade had passed since Rachel Carson alerted Americans to the environmental and health risks of synthetic insecticides. Most, if not all, of the legislative effort during the years leading up to the ban on DDT, dieldrin, and aldrin was concentrated on the persistent chlorinated hydrocarbons. The extensive toxicological research on organophosphates, Carson’s significant concern regarding wildlife and human effects, and extensive testimony in hearings at the federal level would naturally lead one to expect comparable legislative scrutiny for these highly toxic chemicals. But such examination was delayed.
On October 14, 1964, in a symposium on environmental health hazards at the 148th meeting of the American Chemical Society, DuBois, who had linked the organophosphates to cholinesterase inhibition, presented his theory that humans probably developed a resistance to toxicity from the prolonged low consumption of organophosphate insecticides. DuBois reasoned that since dogs and rats developed resistance to organophosphates after just ten days of exposure, humans exposed regularly to such chemicals might also develop resistance. Experimentally, DuBois found that when the acetylcholine level was increased over a period of several days, cells that it would normally have stimulated became somewhat resistant to its effects. He concluded: “This resistance explains why persons who are occupationally exposed repeatedly to organophosphates often fail to show symptoms of poisoning although their ability to detoxify acetylcholine is impaired.”5 In time, DuBois’s view would change.
Five years later, DuBois warned that pesticide poisonings were widespread in the United States and more common in urban and suburban areas where people valued highly manicured lawns of grass. He argued that thrift and federal regulations compelled farmers to minimize pesticide use. According to DuBois, a host of mild symptoms, including blurred vision, sweating, excessively watery eyes, excessive salivation, diarrhea, and tightness in the chest, could all be signs of pesticide poisoning (such a statement resonated with Kallet and Schlink’s worries about chronic lead poisoning thirty-five years earlier and with Morton Biskind’s concerns regarding DDT). He repeated earlier warnings regarding the effect of pesticides on drug efficacy, and he added weight loss to the list of risk factors (losing weight could release pesticides from stored fat into the bloodstream). DuBois identified chlorinated hydrocarbons as the cause of these problems, but he mentioned the significant risk of direct exposure to organophosphates.6
After the EPA banned DDT from use in the home and on lawns, trees, and gardens near the end of 1971, DuBois warned that substitutes like parathion might increase the incidence of poisonings. DuBois believed that the ban reflected a shift in priorities from medical threats to man to concern about chemicals in the environment. He worried that physicians would become increasingly involved in the treatment of pesticide poisonings in urban communities.7 He was concerned mainly that parathion or some other highly toxic organophosphate would be substituted for DDT, and he noted a striking increase in the number of cases of poisoning by such chemicals. With respect to human toxicity alone, DuBois believed that DDT was the safer choice. He noted that there had been a “remarkably small” number of cases of acute human DDT poisoning, and that the most significant risk was mild (and reversible) liver damage.8
Like many other scientists, DuBois struggled to reconcile data from wildlife studies with his own research on human health effects. His research on cholinesterase inhibition and organophosphate insecticides indicated that parathion and other chemicals in the class were highly toxic to humans. Replacing DDT (of minimal acute mammalian toxicity and uncertain chronic toxicity in humans) with a known hazard like parathion made no sense, regardless of mounting evidence of chronic effects of DDT in wildlife. The manufacturers of DDT presented a similar argument in defending their product. They, too, reasoned that DDT would have to be replaced by highly toxic chemicals like parathion, thus increasing risks to consumers. Ruckleshaus noted the hazards of parathion and other organophosphates: “The introduction into use of organophosphates has, in the past, caused deaths among users… . A survey conducted after the organophosphates began to replace chlorinated hydrocarbons in Texas suggests a significantly increased incidence of poisonings.”9 Yet DuBois’s warnings went unheeded. His death from lung cancer in 1973 at the relatively young age of fifty-five effectively ended the rich history of the Tox Lab at the University of Chicago, but its legacy continued at numerous universities across North America through the efforts of the many toxicologists who had received their education and training at Chicago. Legislation focused on the environmental effects of pesticides despite DuBois’s concerns.
Amid continuing debates regarding DDT, several prominent court cases regarding pesticides, and nearly two years of hearings focused on deficiencies with FIFRA, Congress passed the Federal Environmental Pesticide Control Act (FEPCA) of 1972.10 The product of political compromise on the part of the Nixon administration, the bill that led to FEPCA was criticized by both farmers and environmentalists.11 As we have seen, FIFRA required registration once a pesticide was determined to be effective and safe when used as directed. John Wargo noted that FEPCA, in contrast with FIFRA, required manufacturers to “demonstrate that a pesticide would perform its ‘intended function’ and, ‘when used in accordance with widespread and commonly accepted practice,’ would not cause ‘unreasonable adverse effects on the environment.’ ”12 “Unreasonable adverse effects on the environment” applied to both man and the environment and took into account the economic, social, and environmental costs and benefits of the use of any pesticide. Since Congress neglected to define key terms such as “risk,” “cost,” and “benefit,” FEPCA left the EPA in a precarious regulatory position.
The 1972 law did establish two categories for pesticides: general use and restricted use. General use pesticides were unlikely to cause adverse effects; restricted use applied to the more dangerous pesticides that could cause “unreasonable adverse effects” even if used in accordance with label instructions. According to FEPCA, restricted use pesticides could be used only “under direct supervision of a certified applicator.” However, the law allowed for delegation to any competent person under the supervision of a certified applicator. Wargo commented: “The health and safety of the public thus rests on whether the applicator, trained or not, complies with the special precautionary measures provided with the restricted compound.”13 Agricultural chemical manufacturers supported the new legislation because they approved of the certified applicator provision, which was applied to a limited number of chemicals. Designating some pesticides as restricted removed regulatory pressure from the majority of other chemicals. A 1975 amendment further relaxed the restrictions by forbidding the EPA from testing “an applicator’s knowledge of a pesticide’s potential to injure health or the environment.”14
FIFRA provided the prerogative to suspend or cancel the registration for a pesticide if it posed an “imminent hazard to the public,” without further clarification as to the precise meaning of this phrase. FEPCA, however, defined “imminent hazard” as “a situation which exists when the continued use of a pesticide during the time required for cancellation proceedings would be likely to result in unreasonable adverse effects on the environment or will involve unreasonable hazard to the survival of a species declared endangered by the Secretary of the Interior.”15 With the passage of FEPCA, it became the EPA’s responsibility to reregister nearly sixty thousand chemicals. When the EPA identified that a pesticide had an adverse effect on the environment, it sent cancellation notices to the manufacturers, but such notices merely signaled that the EPA had initiated a review of all available data regarding the chemical’s toxicological and ecological effects. Given the poor quality of data collected by the USDA under FIFRA, such reviews could extend for years, during which time manufacturers continued to produce and distribute the chemical.
Even after it suspended or canceled a compound, the EPA typically permitted the use of the existing supplies without recall. FIFRA included an indemnification clause that
required EPA “to purchase, collect, and dispose of any recalled products.” Given that most pesticides had been registered by the USDA under the provisions of FIFRA, it proved to be a challenge for the EPA to obtain high-quality evidence regarding toxicity and fate of pesticides for re-registration decisions as well as decisions to classify pesticides for general or restricted use. Most of the data that the USDA collected under FIFRA addressed the efficacy and efficiency of chemicals in controlling pests rather than toxicity and environmental fate. Moreover, much of the data was more than a decade old. Wargo noted, “EPA’s role has therefore been to manage the scientific process, judge the potential for unreasonable hazard, and then adjust existing use entitlements.”16
As noted above, FEPCA was supported by industry, especially since one stipulation involved indemnification, the compensation of manufacturers for stocks of pesticides that were either canceled or suspended. Chemical companies viewed indemnification as a form of insurance that was necessary for them to invest in the research and development of new pesticides, a potentially costly enterprise. Some environmentalists came to look upon indemnification as a deterrent to federal suspension or cancellation, since the Office of Pesticide Programs within EPA would bear the costs of indemnification. In fact, as Wargo has shown, between 1972 and 1988, EPA indemnified manufacturers of several herbicides and insecticides, spending in excess of sixty million dollars in the process.17 In 1988, Congress revised the indemnification clause and ended financial protection for manufacturers yet continued to protect farmers and applicators who could be indemnified by the regular federal Judgment Fund as directed by the Treasury Department rather than the EPA Office of Pesticide Programs. Despite the challenges posed by classification of pesticides for general or restricted use, re-registration, and indemnification, FEPCA guided pesticide regulation from 1972 forward. Significantly, FEPCA established, as part of federal statute, the protection of the environment as well as human health from the damaging effects of pesticides.18