Opinion ID: 365968
Heading Depth: 3
Heading Rank: 2

Heading: EPA's factual determination of the particular risks here.

Text: 82 We now review the evidence presented by EPA, industry petitioners, and others. EPA did not rely on a single approach or study, but acted on the basis of a variety of studies and types of evidence. Under the substantial evidence test, it is not necessary that all the evidence, or even most of the evidence, point in one direction. The evidence supporting the agency's conclusion must be such, in light of all of the evidence on the record as a whole, that a reasonable mind might accept (it) as adequate to support (the) conclusion. Consolidated Edison Co. v. NLRB, 305 U.S. at 229, 59 S.Ct. at 217. The evidence on scientific matters need not consist of one dispositive study, but may be varied and cumulative. 84 83 We have structured our review under the substantial evidence test according to the primary factors of section 307(a)(2): toxicity (including carcinogenicity), persistence, and degradability as they relate to affected organisms. 85 84
85 The evidence presented concerning toxicity may be divided into (i) evidence bearing on aquatic organisms, (ii) evidence bearing on man, and (iii) evidence concerning the special quality of carcinogenicity.i. Aquatic organisms 86 EPA's Criteria Document, See App. II, and evidentiary affidavits summarized studies concerning adverse effects of all PCBs on a wide range of aquatic organisms. PCBs showed some variation in toxicity: sometimes less chlorinated PCBs were more toxic than more chlorinated PCBs, and sometimes vice-versa, with few systematic tendencies. 42 Fed.Reg. 6534, 6541. 86 87 Petitioners contended that EPA's evidence as to aquatic effects does not support a prohibition. They pointed out that EPA found that aquatic organisms could live with a minimal level of PCBs in the water. 87 Indeed, EPA originally proposed a low effluent standard for PCBs rather than a prohibition. New evidence concerning effects on mammals, not effects on aquatic organisms, led to the prohibition. However, this is not to say that EPA's prohibition is unsupported by the aquatic evidence. Although mammalian evidence appears to have tipped the scales, the evidence concerning aquatic dangers lent support to a prohibition. That evidence showed that, even at low levels of discharge, PCBs might build up over time to levels that would menace aquatic organisms. 88 88 ii. Man 89 EPA's Criteria Document and evidentiary affidavits summarized studies concerning adverse effects of PCBs on a wide range of mammals. EPA deemed the animal studies relevant, in part because some mammals are exposed to PCBs in their fish diet, E. g., domesticated mink, but mainly because mammalian data reflect risks to humans that cannot be readily determined through studies about humans. For the reasons previously discussed, the Criteria Document summarized many studies on more chlorinated PCBs, 89 but almost none on less chlorinated PCBs. See note 66 Supra & accompanying text. After the preparation of the Criteria Document, during the hearings EPA brought forth a few recent studies about the effects of less chlorinated PCBs. These studies lacked the wealth of detail of the studies on more chlorinated PCBs, but did show ill effects. 90 90 In addition to animal studies, EPA summarized some studies on humans, relating to occupational diseases 91 and poisoning incidents. 92 These studies dealt only with effects of more chlorinated PCBs. 91 In opposition, industry petitioners criticized EPA's studies of less chlorinated PCBs. 93 They sought to minimize evidence of the effects of more chlorinated PCBs by asserting that less chlorinated PCBs were different. 94 92 We hold that EPA's toxicity evidence provided support for the prohibition. It is well established that evidence concerning toxic effects on mammals is probative of dangers to man. Although extrapolation of data from mice to men may be quantitatively imprecise, it is sufficient to establish a 'substantial likelihood' that harm will result. EDF v. EPA (aldrin and dieldrin), 167 U.S.App.D.C. 71, 78, 510 F.2d 1292, 1299 (1975). Similarly, evidence concerning occupational diseases and incidents of poisoning appears to be very probative of dangers to man. 95 93 As we have held, EPA did not err in using data generated in studies of more chlorinated PCBs in dealing with less chlorinated PCBs. Industry petitioners' criticisms of EPA's studies of less chlorinated PCBs, while relevant, do not preclude EPA from considering the studies to be support for a prohibition. 94 iii. Carcinogenicity 95 In the EPA proceedings, as in the public debate over PCBs, 96 an issue of considerable importance was whether PCBs cause cancer. EPA introduced studies showing that exposure to more chlorinated PCBs produces cancer and cancer-like growths in rats. App. II 251-53 & Appendix D. EPA also introduced studies showing that more chlorinated PCBs are mutagenic, App. II 254, which, according to commentators, suggests that they may be carcinogenic. 97 Finally, EPA introduced studies that PCBs, including less chlorinated PCBs, are enzyme inducers, 98 indicating that they may be co-carcinogenic that is, that they may produce cancer when they act in combination with other substances. 99 EDF introduced evidence showing that on-the-job exposure to more chlorinated PCBs decades ago resulted eventually in a high incidence of cancer. App. I 168. 96 Industry petitioners respond that the evidence that less chlorinated PCBs are carcinogenic is far from conclusive. Again, they earnestly contend that evidence concerning more chlorinated PCBs fails to support regulation of less chlorinated PCBs. In response to the studies showing that less chlorinated PCBs are enzyme inducers, they introduced expert testimony disputing that enzyme inducers are necessarily carcinogenic or co-carcinogenic. The role of enzyme induction, especially in chemical carcinogenesis, is not as yet very well understood. . . . (I)t must remain highly speculative to deduce enhancement of chemical carcinogenesis by enzyme induction by PCBs. App. I 234 (testimony of Dr. Mueller). 97 After review of the authorities on the difficult issue of carcinogenic effect, we conclude that EPA's evidence furnishes adequate support for its prohibition. An administrator has a heavy burden to explain the basis for his decision to permit the continued use of a chemical known to produce cancer in experimental animals. EDF v. Ruckelshaus (DDT), 142 U.S.App.D.C. 74, 86, 439 F.2d 584, 596 n. 41 (1971); Accord, EDF v. EPA (heptachlor and chlordane), 179 U.S.App.D.C. 43, 50, 548 F.2d 998, 1005 (1976), Cert. denied, 431 U.S. 925, 97 S.Ct. 2199, 53 L.Ed.2d 239 (1977); EDF v. EPA (aldrin and dieldrin), 167 U.S.App.D.C. at 74, 510 F.2d at 1302; See EDF v. Department of Health, Education and Welfare, 138 U.S.App.D.C. at 388-90, 428 F.2d at 1090-92. When firm evidence establishes that a chemical is a carcinogen, statutes generally leave an administrator no alternative but to step in to protect the public. 98 On the other hand, when the evidence is less than firm, but merely suggests that a chemical may be a carcinogen, the same heavy burden may not attend administrative inaction. The decision to act in such a case has been held to fall within the discretion of the Administrator. For example, in Reserve Mining Co. v. EPA, 514 F.2d 492 (8th Cir. 1975) (en banc), EPA sought to abate discharge of mining refuse into Lake Superior under an acceptable but unproved medical theory, that the discharges were carcinogenic. 514 F.2d at 529. The court concluded that the discharges should be abated, even though there would be a heavy cost, including possible loss of many jobs, to the local economy. Id. at 514-20, 535-40. Similarly, in Certified Color Manufacturers Association v. Mathews, 177 U.S.App.D.C. 137, 150, 543 F.2d 284 (1976), the Food and Drug Administration (FDA) terminated its provisional approval of a color additive used to dye food on the basis of a vigorously debated study of the additive's carcinogenic effects. This court concluded that the FDA action should be upheld, based upon FDA's scientific judgment that the study was not conclusive, but was merely suggestive of carcinogenicity. Id. 177 U.S.App.D.C. at 150, 543 F.2d at 297. Courts have traditionally recognized a special judicial interest in protecting the public health, particularly where 'the matter involved is as sensitive and fright-laden as cancer.' Where the harm envisaged is cancer, courts have recognized the need for action based upon lower standards of proof than otherwise applicable. Id. 177 U.S.App.D.C. at 150, 543 F.2d at 297-98 (footnotes omitted) (quoting EDF v. EPA (DDT), 150 U.S.App.D.C. 348, 358, 465 F.2d 528, 538 (1972)). The courts have frequently upheld regulations based on evidence of carcinogenic effects. See, e. g., American Iron & Steel Institute v. OSHA, 577 F.2d at 840, 841 (coke oven emissions); Society of the Plastics Industry v. OSHA, 509 F.2d at 1311 (vinyl chloride); Synthetic Organic Chemical Manufacturers Association v. Brennan, 506 F.2d 385, 387 (3d Cir. 1974) (industrial chemicals), Cert. denied, 423 U.S. 830, 96 S.Ct. 50, 46 L.Ed.2d 48 (1975); Synthetic Organic Chemical Manufacturers Association v. Brennan, 503 F.2d 1155, 1159-60 (3d Cir.) (same), Cert. denied, 420 U.S. 973, 95 S.Ct. 1396, 43 L.Ed.2d 653 (1974). 99 These cases demonstrate the inevitable tension attending regulation of carcinogens. Frequently, such regulations have severe economic impact. Indeed, sometimes, as alleged by industry petitioners in this case, such regulations may jeopardize plants or whole industries, and the jobs depending on them. In such circumstances, the temptation to demand that the agency furnish conclusive proof of carcinogenicity as support for the regulations is great. However, the decision to delegate authority to an agency to control suspected carcinogens is a legislative judgment that is not open to question in this court. Congress's direction to EPA to protect against incompletely understood dangers could not be carried out if we were to adopt the proof requirements advocated by industry petitioners. 100 What scientists know about the causes of cancer is how limited is their knowledge. 100 The record in this case demonstrates that it may take decades for human exposure to carcinogens to result in cancer; 101 in the meantime, the case for inferring a cancer danger with respect to an incompletely understood substance is vigorously disputed. If regulation were withheld until the danger was demonstrated conclusively, untold injury to public health could result. Accordingly, we find that Congress has allowed EPA to support a prohibition on the basis of strongly contested and merely suggestive proof. We conclude that the evidence in this case is at least suggestive of carcinogenicity and thus supports EPA's decision. 101
102 EPA summarized studies showing that PCBs tend to accumulate in the environment over many years, are mobile, and adhere to sediments. 102 This court has noted before that such characteristics intensify the dangers posed by toxic substances, because they increase the exposure of persons and vulnerable organisms of all kinds to those substances. See EDF v. EPA (heptachlor and chlordane), 179 U.S.App.D.C. at 53, 548 F.2d at 1008; EDF v. EPA (aldrin and dieldrin), 167 U.S.App.D.C. at 73, 510 F.2d at 1301. 103 Accordingly, these studies provide support for EPA's prohibition. 103
104 EPA summarized a number of studies concerning the degradation of both less and more chlorinated PCBs by living organisms. PCBs were shown to resist degradation, to bioaccumulate (build up) to high levels in simple organisms, and then to bioaccumulate further as those simple organisms are consumed by higher organisms. 104 42 Fed.Reg. 6539-41. When degradation does occur, it may result in creation of other harmful substances, either as intermediates, or as end products of degradation. 105 Industry petitioners disputed EPA's evidence, and produced their own evidence that less chlorinated PCBs are more easily metabolized and eliminated, and less likely to bioaccumulate than more chlorinated PCBs. They also contended that these substances degrade by safe routes into non-dangerous substances. App. I 209-12, 237-39. 105 However, the conclusions advanced by industry petitioners do not necessarily weaken the support for EPA's prohibition. It was not necessary for EPA to prove that less chlorinated PCBs were as dangerous as more chlorinated PCBs in order to justify a prohibition. The central issue is not whether less chlorinated PCBs are less degradable than more chlorinated PCBs, but whether less chlorinated PCBs are insufficiently degradable. Our task in reviewing the record is not to choose between these conflicting studies, but rather to determine whether EPA's decision had substantial evidence on the whole record. Viewed as a whole, the record provided substantial support for EPA's conclusions. 106