Opinion ID: 338705
Heading Depth: 2
Heading Rank: 2

Heading: Overview of the Evidence

Text: 96 Petitioners vigorously attack both the sufficiency and the validity of the many scientific studies relied upon by the Administrator, while advancing for consideration various studies allegedly supportive of their position. The record in this case is massive over 10,000 pages. Not surprisingly, evidence may be isolated that supports virtually any inference one might care to draw. Thus we might well have sustained a determination by the Administrator not to regulate lead additives on health grounds. That does not mean, however, that we cannot sustain his determination to so regulate. As we have indicated above, we need not decide whether his decision is supported by the preponderance of the evidence, nor, for that matter, whether it is supported by substantial evidence. 79 To the contrary, we must sustain if it has a rational basis in the evidence. Keeping in mind the precautionary will endanger standard under which the Administrator acted, we have no difficulty in terming his decision rational. 97 A word about our approach to the evidence may be in order. Contrary to the apparent suggestion of some of the petitioners, we need not seek a single dispositive study that fully supports the Administrator's determination. Science does not work that way; nor, for that matter, does adjudicatory fact-finding. Rather, the Administrator's decision may be fully supportable if it is based, as it is, on the inconclusive but suggestive results of numerous studies. By its nature, scientific evidence is cumulative: the more supporting, albeit inconclusive, evidence available, the more likely the accuracy of the conclusion. 80 If, as petitioners suggest, one single study or bit of evidence were sufficient independently to mandate a conclusion, there would, of course, be no need for any other studies. Only rarely, however, is such limited study sufficient. Thus, after considering the inferences that can be drawn from the studies supporting the Administrator, and those opposing him, we must decide whether the cumulative effect of all this evidence, and not the effect of any single bit of it, presents a rational basis for the low-lead regulations. 98 While we have studied the record with great care, we do not discuss it all here; to do so would make this already lengthy opinion completely unwieldy. Instead, we shall briefly review the bases for the Administrator's conclusions that petitioners have singled out for special attack. 81 Before we turn to those issues, however, we should note that some things appear to be uncontested. Thus petitioners seem to concede the following: that lead serves no known purpose in the human body; that lead in sufficiently high quantity is destructive to the body, causing anemia, severe intestinal cramps, paralysis, neurologic damage, and, in sufficient dosage, death, Third Health Document at III-1, 2, JA 54-55; that more than 250,000 tons of lead per year are used in production of lead additives, accounting, according to EPA, for approximately 90 percent of all airborne lead, 82 id. at Table II-1, JA 46; that lead concentrations in the air over our largest cities are 2,000 times greater than lead concentrations in the air over the mid-Pacific, NAS Report at 205; that lead in the ambient air contributes to body blood lead levels, Nalco Supp.Br. at 37; supplemental brief of petitioners PPG Industries and E. I. duPont de Nemours & Company (hereinafter PPG/duPont Supp.Br.) at 23; and that blood lead levels are a reasonable indication of the body's lead burden. Stripped of their generalized and largely unsubstantiated claims of bias and distortion of the evidence, petitioners principally challenge three EPA conclusions: (1) that, based on a preliminary determination that blood lead levels of 40 ug are indicative of danger to health, elevated blood lead levels exist to a small but significant extent in the general adult population, and to a very great extent among children, Third Health Document at VII-3, JA at 144; (2) that airborne lead is directly absorbed in the body through respiration to a degree that constitutes a significant risk to public health; and (3) that airborne lead falls to the ground where it mixes with dust and poses a significant risk to the health of urban children. 99
100 a. Blood lead levels of 40 ug are indicative of danger to health. Although recognizing that a blood lead level of 40 ug does not represent a sharp demarcation between health and disease, the Administrator found it prudent to regard blood lead levels over 40 ug/100g as indicators of lead intake that should be prevented. Third Health Document at III-11, JA 64. Petitioners contest this determination. Much of their argument, however, adds up to nothing more than that they are unhappy the Administrator chose to exercise his judgment and think the statute does not permit such discretion. Petitioners cite medical studies that show not that a blood lead level of 40 ug is unrelated to danger, but that scientists are simply uncertain about the effect of such blood levels. Ethyl brief at 37-38 and Supp.Br. at 41-42; PPG/duPont brief at 11-12; Nalco brief at 14. But, as we have seen, exercise of reasoned discretion based on the evidence is not only permitted, but mandated, by Section 211(c)(1)(A). The administrator recognized from the outset that the health effects of varying human blood lead levels were uncertain and that continuing research was necessary. 83 His determination of the 40 ug level is, on its face, an assessment of risks based on the known facts and not improper as such. 101 In addition to their generalized attack on the Administrator's power, petitioners challenge the sufficiency of the evidence to support his determination. Under the will endanger standard, however, we find the evidentiary basis for the Administrator's determination to be more than adequate. Petitioners do not contest the recommendation of the United States Public Health Service that 80 ug be taken as the standard of unequivocal lead poisoning, or the Service's recommendation that blood lead levels of 50-79 ug justify immediate evaluation for possible lead poisoning. Medical Aspects of Childhood Lead Poisoning, HSMHA Health Reports, 86(2), 140-143 (1971), cited in Third Health Document at IV-3, JA 71. What draws petitioners' fire is only the last of the Service's recommendations, adopted by EPA, that for older children and adults a blood lead concentration of 40 ug or more per 100 ml of whole blood    be considered evidence suggestive of undue absorption of lead, either past or present. Id. While the reasonableness of establishing as a danger point a lead exposure level somewhat lower than that at which actual damage may occur seems both logically unassailable and well within the intent of the will endanger standard, the Administrator went beyond that sufficient conclusion. He recognized, and warned of, possible dangers, particularly to children, from lead at the 40-60 ug level, and even below, thereby suggesting that the Public Health Service's recommended danger level, designed for adults, may be set too high. Because this latter evidence was only suggestive, however, the Administrator conservatively settled on the 40 ug standard. 84 Third Health Document III-5, 6, 7, 8, JA 58-61. Such a prudent determination is well within the Administrator's discretion under the will endanger standard. We have examined the evidence relied upon carefully and, while it is not necessary to summarize it here, 85 we find that it provides a rational basis for the Administrator's determination. 102 b. Blood lead levels are elevated among a small, but significant, number of adults and a considerable number of children. Again, petitioners challenge the Administrator's determination as unsupported by the evidence. The problem here is one of choosing among the items of evidence. Petitioners rely heavily on the results of the so-called Seven Cities Study, 86 which found a very small percentage of adults with elevated (in excess of 40 ug) blood levels. 87 PPG/duPont brief at 12-15; Nalco brief at 16. The Administrator, on the other hand, finds serious methodological flaws in the Seven Cities Study that limit its usefulness, 38 Fed.Reg. 33735, and relies instead on studies which concededly support his conclusion, Third Health Document at Tables VII-1, 2 & 3, JA 145-147, but which petitioners score as representative only of certain occupational groups. PPG/duPont brief at 15; Nalco brief at 15-16. 103 Having analyzed this evidence and the arguments of the parties, we would again defer to the Administrator's judgment. First we note that, while contesting the source of lead exposure, petitioners do not challenge at all the Agency's conclusion that blood lead levels are elevated in a large number of children, including a possible 25 percent of all preschool children living in substandard housing. 88 Third Health Document at Table VII-3, JA 147. 104 Next, while the studies relied on by the Administrator are largely of various occupational groups, they are frequently occupations whose only exposure to lead is through the ambient air in which their workers policemen, mailmen, service station employees, parking lot attendants, and the like are forced to spend their working hours. 89 Third Health Document at Table VII-1, JA 145. Contrary to the arguments of petitioners, studies of occupational groups are often particularly valuable in acting as an early warning system of possible effects on the public at large. The intensive exposure in particular occupations essentially accelerates the effects of long-term exposure of the general public and provides an identifiable, highly exposed, and readily accessible group of research subjects. See D. Clark & B. MacMahon, Preventive Medicine 26 (1967) (hereinafter Clark & MacMahon). Thus much of the evidence in Reserve Mining of the danger to the general public of absorption of asbestos particles came from epidemiological studies of asbestos workers. Reserve Mining Co. v. EPA, supra, 514 F.2d at 507. 90 Because of this the occupational data are not only in themselves indicative of high blood lead levels among a significant portion of the adult population, but they suggest the future likelihood, absent controls, of increasing high blood lead levels among even more widely dispersed portions of the public. In any case, however, the evidence relied upon by the Administrator was not only of occupational groups. Some evidence of high blood lead level relates to such specialized groups as Drivers of Cars, Male Commuters, and Urban residents. Third Health Document at Tables VII-1 & 2, JA 145-146. 105 Petitioners argue that the negative conclusions of the Seven Cities Study and several other studies should outweigh the positive indications of the studies described above. PPG/duPont Supp.Br. at 16-23; NPRA Supp.Br. at 5-8. The Administrator disagreed, and we cannot fault his conclusion. Because of the many uncontrolled variables in epidemiological studies, valid conclusions may be obscured. But, while the possibility of false negative conclusions is a real one, the possibility of false positive findings is considerably less likely. Clark & MacMahon, supra, at 100. Thus the Administrator credited the occupational and other studies reporting a small, but significant, portion of the general population with elevated blood lead levels and discounted the negative studies on which petitioners rely. Third Health Document at VII-3, JA 144. We cannot say his conclusion was arbitrary or capricious. 106 2. Automobile Lead Emission Products are Directly Absorbed in the Body to a Significant Extent 107 Since it is apparent from the face of his decision and the Third Health Document that the Administrator considered all the evidence before him, the only issue is whether he treated that evidence in a rational manner. Petitioners have now conceded that lead emissions are directly absorbed in the body from the ambient air, and they challenge only whether the extent of absorption is significant enough to justify these regulations. Nalco Supp.Br. at 37; PPG/duPont Supp.Br. at 23. The Administrator's conclusion that lead absorption from the air is significant is amply supported by the record in this rule-making. 108 The Administrator relied on three types of evidence: theoretical, epidemiological, and clinical studies. The theoretical evidence consisted of a set of calculations designed to estimate the amount of lead in the air which, when added to an average dietary intake, would suffice to bring the blood lead burden of a standard man up to 40 ug. 91 These calculations indicated that the 40 ug level can be reached by exposure to ambient air lead concentrations no greater than those now found in parts of our larger cities. Significantly, the results of two clinical experiments support the estimates derived from these theoretical calculations. The calculations, as well as petitioners' misguided attacks on their validity, are discussed in Appendix A to this opinion. See pages --- to --- of --- U.S.App.D.C., pages 55 to 56 of 541 F.2d infra. 109 The second type of evidence relied upon by the Administrator in reaching his conclusion that airborne lead contributes significantly to the human lead body burden consisted of epidemiological research. Epidemiologists study the effects of various phenomena on humans under uncontrolled or natural conditions. These effects are correlated with other observed facts in an attempt to develop significant relationships among the data. The science is limited, however, in that inferences may be drawn, but relationships cannot be proved by the correlations alone. JA 583. The studies before the Administrator were of large groups of people; correlations were sought between blood lead level and exposure to lead in the ambient air. The studies were confounded, however, by the multiple sources of lead. Since diet accounts for a major portion of the body lead burden, an individual's blood lead level varies not only according to his exposure to lead in the ambient air, but according to his daily dietary intake of lead. Wide variations in dietary lead intake, which are common, can completely mask the effects of air lead absorption. Nonetheless, none of the epidemiological studies could control or measure dietary lead intake. This uncertainty in the data severely limited the usefulness of the broadly conceived epidemiological studies and led the Administrator to rely instead on data limited to situations in which dietary exposure could roughly be termed constant. 110 Following this rationale, the Administrator focused on the consistent relationship found between air and blood lead levels within particular metropolitan areas, rather than on the lack of such a relationship between areas. 92 See pages --- to --- of --- u.s.APP.D.c., PAGes 57 to 58 of 541 F.2d infra. The Administrator also drew support for his conclusion that lead in the air significantly affects lead in the blood from studies conducted in single neighborhoods. There, too, confounding factors were minimized by proximity, and there, too, a clear direct relationship was found. See pages --- to --- of --- U.S.App.D.C., pages 59 to 61 of 541 F.2d infra. Thus the epidemiological studies, although perhaps insufficient to justify the Administrator's decision if considered singly or even collectively, were reasonably relied on as part of the basis for the low-lead rules. 111 The conclusions the Administrator drew from theoretical calculations and the epidemiological studies are significantly bolstered by two important clinical studies. Clinical studies are laboratory experiments on humans in which variables can be controlled and causal relationships demonstrated. Clinicians attempt to reproduce atmospheric conditions in the laboratory and measure the response to pollution of small numbers of humans chosen to represent the population at large. JA 583. Because of its necessarily significant intrusion on the subjects' lives, clinical research is limited in the number of subjects it can study. Nonetheless, the two clinical studies are especially valuable since they are the only attempts to control or account for dietary lead intake. Thus they sought to measure the contribution of respiratory absorption of lead unmasked by variations in dietary lead. Both studies found that airborne lead provided a significant portion of the lead in the blood of the experiments' subjects. Moreover, the amount of lead actually absorbed from the air during these studies corresponded closely with the amount EPA's theoretical calculations predicted would be absorbed. See pages --- to --- of --- U.S.App.D.C., pages 61 to 63 of 541 F.2d infra. 112 While we must consider petitioners' arguments carefully, the necessary existence of limitations and inconsistencies in the data remind us to observe carefully our limited appellate function. It does not matter whether or not we agree with the Administrator's determination. Nor does it matter whether the evidence might support a conclusion contrary to that reached by the Administrator. All that is of concern to us is that there be a rational basis in the evidence for the conclusion reached. We cannot say there is not. The bulk of the evidence cited supports the Administrator. See Appendix A to this opinion. The Administrator treated all the evidence in a consistent and rational manner. This treatment disposed of most of the studies relied upon by petitioners, leaving the plain conclusion that lead emissions form a significant part of the human body burden. Particularly in light of the precautionary nature of the will endanger standard, we cannot find the Administrator's conclusion to be arbitrary or capricious. Accordingly, we must uphold his determination. 113 3. Lead Exposure from Dustfall Threatens the Health of ChildrenFirst, as we have demonstrated above, see pages --- - --- of --- U.S.App.D.C., pages 12-20 of 541 F.2d supra, the will endanger standard is a precautionary standard that embraces a wide range of permissible proof. It is therefore no objection to the dustfall hypothesis that it is merely a hypothesis. A supportable and reasonable hypothesis may well form the basis for regulations under Section 211(c)(1)(A). Indeed, the totality of evidence relied upon in the Reserve Mining case constituted no more than such a hypothesis. See pages --- - --- of --- U.S.App.D.C., pages 45-46 of 541 F.2d infra. 114 Second, although it seems too obvious to mention, the Administrator understood and expressly recognized that leaded paint is the primary cause of clinical lead poisoning in children, 38 Fed.Reg. 33735. Although petitioners repeatedly try to rebut EPA conclusions by stating this fact, the Administrator was well aware of it and his evaluation of the data before him invariably accounted for it. We do not believe the importance of lead paint to the lead poisoning problem in children invalidates the Administrator's reliance on the dustfall theory. The Administrator justified his hypothesis as a basis for regulation on grounds that dustfall may be regulated far more readily than leaded paint, that dustfall contributes significantly to the threat from leaded paint by raising blood lead levels so as to make lead poisoning easier to contract, and that even when acute lead poisoning does not develop absorption of lead dustfall may cause undesirable and avoidable subclinical effects. 38 Fed.Reg. 33736-33737. 93 We have held, see pages --- - --- of --- U.S.App.D.C., pages 29-31 of 541 F.2d supra, that concern about the cumulative impact of exposure to various lead sources may justify regulation of lead additives under Section 211(c)(1)(A). Thus we cannot say that these reasons for regulation, when added to the demonstrated danger to the general public from respiratory absorption of lead emissions, see Appendix A to this opinion, and if supported by the evidence, do not form a permissible basis for the low-lead regulations under the will endanger standard. 115 With these preliminaries settled, we turn to the evidence supporting the Administrator's determination. Since the hypothesis is only a secondary basis for the regulations, and since the evidence cited goes considerably beyond that necessary to establish the hypothesis as reasonable, we shall address only the thrust of petitioners' objections and the Administrator's responses. The logical steps to the Administrator's conclusion are these: 116
117 b. In most circumstances, lead from exhausts and not lead paint or lead from stationary sources is the primary source of lead in urban dust and dirt. 118 c. Children prone to pica, about 50 percent of those between the ages of one and three, eat nonfood objects, including dust and dirt. 119 d. As a result of ingesting dust and dirt contaminated with lead fallout, children can be expected to absorb lead into their bodies. 120 38 Fed.Reg. 33736. If the intermediate steps are supported by the evidence, the validity of the Administrator's conclusion as a reasonable hypothesis is unassailable. Our study of the underlying evidence convinces us that it is firm and convincing, and certainly sufficient to support the Administrator's hypothesis as reasonable. 121 Petitioners concede that lead concentrations are high in the dust near highways and adjacent to homes with lead paint. They contest, however, that high lead concentrations are otherwise prevalent in urban areas. PPG/duPont Supp.Br. at 37 n. 86. The facts rebut their argument. The NAS Panel found that (t)he concentration of lead in street dust and surface soil of large cities is extremely high. NAS Report at 30 (emphasis added). This conclusion was based on a finding that, compared to the usual range of dust lead concentrations of 2-200 parts per million (ppm), dust lead concentrations in cities averaged 1,636 ppm and 2,413 ppm respectively for residential and commercial sites. Even in city parks lead concentrations ranged from 194 ppm to 3,357 ppm. Id. Other evidence of record shows high lead concentrations in Central Park Zoo in New York City, JA 2630, and school playgrounds in Philadelphia, JA 674. 122 Where does this high dust lead content come from? The Administrator concluded that since 90 percent of the lead in the ambient air is from automotive exhausts and since, as petitioners concede, PPG/duPont Reply Br. at 17, the lead eventually settles to the ground, most of the lead in dust is a product of automobile lead emissions. Petitioners do not seriously contest this; indeed their own studies suggest this by showing that lead content in soil decreases with distance from highways. 94 Rather, they argue that lead from paint or stationary sources is the source of lead in dust and dirt in areas where young children play. PPG/duPont Supp.Br. at 37 n. 86. This argument reflects petitioners' consistent refusal to recognize that city children play regularly in city streets, where petitioners concede lead dustfall from automobiles accumulates. PPG/duPont Reply Br. at 17. Since the Administrator's concern about dustfall is based on the harm it may cause city children, petitioners' argument that children are not exposed to automobile dustfall where they play must be rejected. 123 Petitioners do not contest that pica is a common phenomenon among preschool children, although they note that it is a psychological disorder; it is not characteristic of all children   . PPG/duPont Supp.Br. at 37 n. 86. While this is certainly true, pica is characteristic of a significant number of children. Petitioners do not challenge the conclusion of the NAS Panel that pica occurs in at least 50 percent of both middle- and lower-class children. NAS Report at 133. 124 On the basis of this evidence alone it is reasonable to hypothesize that children with pica will ingest dust and dirt containing lead dustfall from automobiles. Indeed, on such limited evidence the NAS Panel accepted the dustfall hypothesis as credible: 125 Airborne lead wastes from such sources as automobile emissions and the weathering and demolition of old buildings can be expected to have a significant additive effect on the total intake. This would be sufficient to evoke compensatory metabolic responses that are now considered subclinical (such as increased urinary ALA), at the very least. It may be estimated that dustfall from airborne lead, if swallowed, can make a significant contribution to a small child's total lead intake and thereby contribute to the occurrence of lead poisoning, especially in urban areas. Even so, the direct ingestion of lead-pigment paints is clearly the principal environmental source in cases of severe acute lead poisoning in young children. 126 NAS Report at 140 (emphasis added). Again petitioners focus on the last sentence and emphasize the danger from leaded paints. Since the Administrator is in agreement with them on the point, however, their arguments are superfluous. 127 Petitioners' primary claims are not addressed to the evidence that establishes the dustfall hypothesis as tenable. Rather, they argue that there is no evidence that lead dustfall from automobiles is in fact swallowed by children with pica. While such proof is not necessary to establish the Administrator's hypothesis as reasonable, see pages --- - --- of --- U.S.App.D.C., pages 44-45 of 541 F.2d supra, we note that a considerable amount of circumstantial evidence does support his conclusion. See Appendix B to this opinion. 128 In any case, all the evidence suggesting that the children with pica tend to eat dust contaminated with lead fallout from automobiles takes the Administrator's theory far beyond the hypothesis stage. He offered only a tentative result, a hypothesis consistent with information provided by a variety of studies. 38 Fed.Reg. 33736. Undoubtedly, he has shown that. Indeed, as reasonable medical hypotheses go, this one is particularly solid. This is vividly demonstrated by recalling the kind of evidence relied upon to justify similar precautionary relief in Reserve Mining. 129 The question in that case was the validity of the hypothesis that ingestion of asbestos fibers was dangerous to health. The reason for concern was that epidemiological studies had associated inhalation of asbestos with cancer. The evidence supporting the hypothesis was of three kinds: (1) a court-sponsored study to determine whether asbestos fibers were present in residents who drank the polluted water; (2) animal studies designed to measure whether asbestos fibers can be absorbed into the body from the stomach; and (3) epidemiological studies associating inhalation of asbestos fibers with gastrointestinal cancer and the theory that this may be due to ingestion of asbestos fibers initially inhaled. Reserve Mining Co. v. EPA, supra, 514 F.2d at 514. Upon review of the evidence the court concluded (1) asbestos fibers were not present in long-time residents; (2) the animal studies were ambiguous on whether asbestos fibers could be absorbed if ingested; and (3) the theory that asbestos workers ingested asbestos fibers as well as inhaled them was no more than a theory, id. at 514-516. Nonetheless, solely on the basis of this evidence, the court concluded that the theory that excess cancers may be attributed to the ingestion of asbestos fibers rests on a tenable medical hypothesis, id. at 516. On the basis of this tenable hypothesis, the court accepted the further hypothesis that asbestos could be ingested from the drinking water and that, therefore, there was a reasonable medical concern for the public health which justified abatement of the asbestos discharge under the endangering language of the FWPCA. Id. at 520. 130 None of these uncertainties cloud the Administrator's dustfall hypothesis. Lead is present in children, and in elevated amounts. Children do ingest dust, and dust is heavily laden with lead. Animal studies prove that ingested lead dust is absorbed into the bloodstream. And epidemiological studies associate high lead concentrations in children with high lead concentrations in dirt and dust, and with proximity to automobiles. Since the automobile is the predominant source of lead in dust, the Administrator's hypothesis stands firm as reasonable, undoubtedly with more support in studies already made than the hypothesis that justified regulation in Reserve Mining. Indeed, the primary difference between this case and Reserve Mining is that the Eighth Circuit justified ordering abatement of asbestos discharges into the water solely on the basis of a hypothesis, 95 while here the hypothesis is offered only as support for the regulations, the primary basis being the demonstrated danger to health posed by inhalation of lead emissions. In this context, and keeping in mind the precautionary nature of the will endanger standard, we have no difficulty in finding the dustfall hypothesis sufficiently well grounded to support the Administrator's limited reliance on it. 96 C. Summary of the Evidence 131 From a vast mass of evidence the Administrator has concluded that the emission products of lead additives will endanger the public health. He has handled an extraordinarily complicated problem with great care and candor. The evidence did not necessarily always point in one direction and frequently, until EPA authorized research, there was no evidence at all. 97 The Administrator reached his conclusion only after hearings spread over several months, consideration of thousands of pages of documents, publication of three health documents, three formal comment periods, and receipt of hundreds of comments. Each study was considered independently; its worth was assessed only after it was measured against any critical comments. From the totality of the evidence the Administrator concluded that regulation under Section 211(c)(1)(A) was warranted. 98 132 In tracking his path through the evidence we, in our appellate role, have also considered separately each study and the objections petitioners make thereto. In no case have we found the Administrator's use of the evidence to be arbitrary or capricious. Having rejected the individual objections, we also reject the overall claim of error. We find the Administrator's analysis of the evidence and assessment of the risks to be well within the flexibility allowed by the will endanger standard. Accordingly, we affirm his determination that lead emissions present a significant risk of harm to the health of urban populations, particularly to the health of city children. 38 Fed.Reg. 33734.