Opinion ID: 443049
Heading Depth: 2
Heading Rank: 1

Heading: Significant Health Risk

Text: 18 Before the Secretary promulgates a new standard, he is required by Sec. 3(8) of the Occupational Safety and Health Act (Act), 29 U.S.C. Sec. 652(8) (1982), to make a threshold determination that (1) the current standard governing the toxin poses a significant health risk, and (2) the risk can be diminished by lowering the standard. Industrial Union Dep't v. American Petroleum Inst. (IUD v. API ), 448 U.S. 607, 642, 100 S.Ct. 2844, 2864, 65 L.Ed.2d 1010 (1980) (plurality); United Steelworkers of America v. Marshall, 647 F.2d 1189, 1246 (D.C.Cir.1980), cert. denied, 453 U.S. 913, 101 S.Ct. 3148, 69 L.Ed.2d 997 (1981). A majority of the Court has endorsed this requirement. See American Textile Mfrs. Inst. v. Donovan, 452 U.S. 490, 505-06 n. 25, 101 S.Ct. 2478, 2488-89 n. 25, 69 L.Ed.2d 185 (1981). 19 Petitioners and intervenor CMA divided the arguments. CMA argues petitioners' challenges to the significant risk determinations required under IUD v. API and made by OSHA on remand. CMA also challenges OSHA's decision to include pentavalent arsenic within the arsenic standard. Petitioners ASARCO, Inc. and Kennecott argue petitioners' challenges to the Secretary's feasibility findings. 20 (a) Standard of Review 21 Section 6(f) of the Act, 29 U.S.C. Sec. 655(f), provides that [t]he determination of the Secretary shall be conclusive if supported by substantial evidence in the record as a whole. Substantial evidence is such relevant evidence as a reasonable mind might accept as adequate to support a conclusion. American Textile, 452 U.S. at 522, 101 S.Ct. at 2497 (quoting Universal Camera Corp. v. NLRB, 340 U.S. 474, 477, 71 S.Ct. 456, 459, 95 L.Ed. 456 (1951) ). Because study of OSHA's attempts to safeguard worker health demands that we consider complex and often conflicting scientific evidence, we elaborate below some of the considerations that must guide our review. 22 Although we must review contradictory evidence in the record, the possibility of drawing two inconsistent conclusions from the evidence does not prevent an administrative agency's finding from being supported by substantial evidence. American Textile, 452 U.S. at 523, 101 S.Ct. at 2497 (quoting Consolo v. FMC, 383 U.S. 607, 620, 86 S.Ct. 1018, 1026, 16 L.Ed.2d 131 (1966) ). Similarly, in United Steelworkers, the D.C. Circuit held, 23 Where the agency presents scientifically respectable evidence which the petitioner can continually dispute with rival, and we will assume, equally respectable evidence, the court must not second-guess the particular way the agency chooses to weigh the conflicting evidence or resolve the dispute. 24 647 F.2d at 1263. 25 In the context of significant risk determinations, OSHA is not required to support its finding ... with anything approaching scientific certainty. IUD v. API, 448 U.S. at 656, 100 S.Ct. at 2871 (plurality). Moreover, we give OSHA some leeway where its findings must be made on the frontiers of scientific knowledge. Id. (citations omitted). And, 26 so long as they are supported by a body of reputable scientific thought, the Agency is free to use conservative assumptions in interpreting the data with respect to carcinogens, risking error on the side of overprotection rather than underprotection. 27 IUD v. API, 448 U.S. at 656, 100 S.Ct. at 2871 (emphasis added) (footnote omitted). See also Ethyl Corp. v. EPA, 541 F.2d 1, 22-33 (D.C. Cir.) (en banc), cert. denied, 426 U.S. 941, 96 S.Ct. 2662, 49 L.Ed.2d 394 (1976) (for eloquent discussion of problems associated with scientific certainty in environmental decisionmaking). 28 It is the Secretary's responsibility to determine what risk he considers to be significant, but in doing so he need not be forced into a mathematical straightjacket. IUD v. API, 448 U.S. at 655, 100 S.Ct. at 2870. He can be reasonable in determining that a one in a thousand risk is significant, id., and be justified in regulating such a risk. We turn now to the facts of this case. 29 (b) The Arsenic Standard and Petitioners' Challenges 30 The epidemiological studies and methodologies used by the Secretary to determine that a significant health risk exists at and below the pre-existing 500 ug/m 3 PEL and that the new 10 ug/m 3 PEL will reduce that risk are discussed in the summary of the regulations. See 48 Fed.Reg. 1895-1903. 11 Although a familiarity with these studies is necessary to resolve whether the standard is supported by substantial evidence, we shall not resummarize them here. Instead, for brevity's sake, we respond primarily to CMA's contentions after we summarize OSHA's findings. 31 On the basis of the studies, OSHA determined that a range of 148-767 excess deaths per 1000 employees was expected at 500 ug/m 3 PEL, and a range of 2.2-29 excess deaths per 1000 employees was expected at 10 ug/m 3 PEL. 48 Fed.Reg. at 1866. OSHA's best estimate of risks in those ranges was 400 excess deaths per 1000 employees at 500 ug/m 3 and 8 excess deaths per 1000 employees at 10 ug/m 3 . 12 Id. Thus, OSHA concluded that the 500 ug/m 3 PEL posed a significant risk, and that the 10 ug/m 3 PEL would substantially reduce that risk. Id. 13 32 CMA's primary argument is that the epidemiological studies of trivalent arsenic, including the Lee-Feldstein, Lee & Fraumeni, Pinto, and Marsh & Enterline studies, relied upon by OSHA to make its risk assessments are flawed and hence cannot constitute substantial evidence. CMA also contends that another study, by Higgins, which found no excess risk of death below the pre-existing standard, is more reliable and relevant than the studies relied on by OSHA. We find these contentions unpersuasive. In fact, we find just the opposite to be true. The studies relied on by OSHA constitute substantial evidence and the Higgins study is critically flawed. Moreover, CMA asks us to hold OSHA to a degree of scientific certainty far more exacting than the Act requires. 14 33 First, as we have already held in maintaining the 10 ug/m 3 PEL during the remand, it is undisputed that exposure to inorganic arsenic at the level of 500 ug/m 3 --which would be permitted were we to vacate the current standard--poses a 'significant' health risk, and ASARCO concedes that exposure at a level above 50 ug/m 3 may present some danger. ASARCO, 647 F.2d at 2. Second, even assuming that the Higgins study is not defective, see infra slip op. at pp. 4022-4024, 746 F.2d at pp. 493 - 494, most of CMA's methodology challenges would require us to evaluate conflicting inferences drawn from comparable or identical evidence. In such a case, we must defer to OSHA. American Textile, 452 U.S. at 523, 101 S.Ct. at 2497; see supra slip op. at p. 4019, 746 F.2d at p. 490. Third, even if we were to evaluate comparable evidence and second-guess OSHA, we would reject CMA's challenges. We now turn to CMA's specific contentions. 34 Exposure Levels. We are not persuaded by CMA's attack on the quantification of arsenic exposure levels in the Anaconda smelter studies of Lee & Fraumeni and Lee-Feldstein. 15 Morris subsequently supplied reasonable quantifications in support of those studies. 48 Fed.Reg. at 1870. After reviewing the record, none of CMA's other challenges to the studies that OSHA relies on persuade us that those studies have defects that should cause us to question their validity. They thus remain as valid evidence supporting OSHA's 10 ug/m 3 standard. 35 Urinary Measurements. CMA also attacks OSHA's reliance on the Enterline & Marsh studies. Enterline and Marsh compared worker urinary arsenic levels at ASARCO's Tacoma smelter with worker incidence of lung cancer. Those studies found an excess risk of cancer at low arsenic exposure levels. OSHA supports its reliance on Enterline & Marsh with Pinto's correlation between airborne arsenic and urinary arsenic levels. 48 Fed.Reg. at 1878-79. CMA contends that such correlations are invalid. Pinto found a correlation, however, and ASARCO itself presented his data as the best available data on the subject at the earlier proceedings. Id. Similar correlations have been accepted by reviewing courts. See, e.g., United Steelworkers, 647 F.2d at 1259-63 (air/lead; blood/lead); cf. Lead Industries Ass'n. v. EPA, 647 F.2d 1130, 1166-67 (D.C.Cir.1980) (discussing airborne lead's eventual arrival in bloodstream); Ethyl Corp. v. EPA, 541 F.2d 1 at 7-9, 30-31 (discussing blood lead levels). After reviewing the record, we also accept the correlations. The Pinto and Enterline & Marsh studies of the Tacoma smelter therefore constitute evidence in support of OSHA's standard. 36 Risk Assessments. CMA also contends that OSHA impermissibly relied on a linear, no-threshold, cumulative dosage model that CMA argues incorrectly determines that there is no safe level of exposure to arsenic. 16 First, CMA contends that OSHA's use of the no safe level (i.e., linear) model is impermissible because the model was not derived through scientific reasoning--but was used as a matter of administrative fiat. CMA's contention is not supported by the record. OSHA's experts in fact adopted the linear assumption of zero risk at zero exposure on the basis of best available evidence, not by administrative fiat as CMA contends. 48 Fed.Reg. at 1886-90. Moreover, the linear model fits the epidemiological data obtained by OSHA's experts far better than the threshold model 17 advocated by CMA does. 48 Fed.Reg. at 1886; see also 48 Fed.Reg. at 1878 (expert opinion of Dr. C.H. Crump). 37 Second, with respect to the cumulative dosage model employed by OSHA, CMA argues that exposure to high levels of arsenic (exposure intensity), rather than long-term exposure at low levels (cumulative exposure), causes cancer. The record, however, supports OSHA's risk estimation method. Contrary to CMA's allegations, the cumulative exposure model is not an unsubstantiated assumption. Instead, the model is supported by direct evidence and expert opinion. After examining many factors including duration of exposure, age, and exposure intensity, OSHA's experts (Brown and Chu), found that duration was the most important single factor in the excess lung cancer risk. 48 Fed.Reg. at 1889. They also acknowledged that exposure intensity was important. Id. CMA's argument, however, that exposure intensity, rather than duration (cumulative exposure at lower exposure levels), is the only critical variable is unpersuasive. OSHA considered the evidence supporting exposure intensity and adequately stated its reasons for preferring duration. 48 Fed.Reg. at 1890. Finally, the no safe level model easily falls within the class of conservative assumptions approved by the IUD v. API plurality. 448 U.S. at 656, 100 S.Ct. at 2871. See supra 746 F.2d at p. 490. We therefore defer to the agency's expertise on this point. See American Textile, 452 U.S. at 523, 101 S.Ct. at 2497; United Steelworkers, 647 F.2d at 1248. 38 Higgins Study. CMA seeks to supplant OSHA's studies and conclusions with those of Higgins. CMA argues that OSHA's rejection of Higgins was unreasonable and an abuse of discretion. We disagree. 39 CMA alleges that the Higgins study reflects most accurately the risks associated with arsenic exposures below 500 ug/m 3 . Higgins hypothesized that no excess risk would occur to workers whose ceiling exposure level was 500 ug/m 3 or below. The record, however, shows that the Higgins study is flawed. 18 Foremost of those flaws is the study's low statistical power (ability to predict). 19 Higgins examined only a limited number of individuals (only 22% of the workers studied by Lee & Fraumeni and Lee-Feldstein at the same plant). Despite CMA's attempts to introduce extra-record evidence now to rebut OSHA's conclusion that the Higgins study was unreliable, we are firmly convinced that the Higgins study does not warrant re-evaluation of the standard. 20 40 In sum, CMA's attempt to discredit and/or supplant OSHA's studies with the Higgins study does not fail just because CMA asks us to choose one comparable study over another (in effect, to second-guess OSHA). See United Steelworkers, 647 F.2d at 1263 (when faced with comparable evidence on both sides, court should defer to OSHA). This case is far easier. CMA's challenge fails because OSHA supports its rule with several reliable studies and CMA asks us to reject those studies in favor of one that is speculative and of questionable validity. 21 41 Here, OSHA considered the Higgins study and rejected it on reasonable grounds, and OSHA's reliance on a reputable body of scientific thought--e.g., the Lee & Fraumeni, Lee-Feldstein, Pinto, and Enterline & Marsh studies--was reasonable. 22 Given the generous standard of review with which we review OSHA regulations--risking error on the side of overprotection rather than underprotection 23 --we hold that OSHA's finding that arsenic poses a significant risk to worker health at the pre-existing 500 ug/m 3 PEL and that the new standard of 10 ug/m 3 will significantly reduce that risk is amply supported by substantial evidence. 24 42 (c) Pentavalent Arsenics 43 CMA also challenges OSHA's inclusion of pentavalent arsenic in the arsenic standard. The Secretary concluded that pentavalent arsenic was a carcinogen and hence poses a significant risk to worker health. 48 Fed.Reg. at 1893-1894. CMA contends that OSHA did not rely on substantial evidence to show that pentavalent arsenic is carcinogenic. Although the question whether substantial evidence supports the Secretary's finding of significant risk is closer here than with trivalent arsenic, we find that substantial evidence supports the Secretary's finding. 44 OSHA initially concluded that pentavalent arsenic was carcinogenic on the basis of a study by Ott. 48 Fed.Reg. at 1893. CMA points out, however, that OSHA itself at one time concluded that the Ott study's methodological limitations prevented it from being used to show adequate dose-response levels. See 43 Fed.Reg. at 19596. Nonetheless, OSHA now reaffirms its inclusion of pentavalent arsenic on the basis of the Ott study and on the subsequent opinions of several additional experts indicating that Ott's study can indeed be used for risk assessment purposes. 48 Fed.Reg. at 1890, 1897-98. OSHA also explains that the Supreme Court's intervening decision in IUD v. API clarified that OSHA was free to use conservative assumptions and err on the side of overprotection. 448 U.S. at 655, 100 S.Ct. at 2870; see supra 746 F.2d at p. 490. Given this clarification, the Secretary decided that the Ott study was sufficiently reliable to support OSHA's regulation of pentavalent arsenic. 48 Fed.Reg. at 1894. 45 We defer to the Secretary on his decision to include pentavalent arsenic in the standard. CMA's contentions on this point do not compel a different result. OSHA states adequate reasons for rejecting the rival Nelson study proffered by CMA. 48 Fed.Reg. at 1893. 25 OSHA also found that new evidence indicates that the Ott study is more reliable than originally thought. 48 Fed.Reg. at 1893-94. 46 As with our consideration of the arsenic standard in general, the deferential standard of review enunciated by the court in IUD v. API, 448 U.S. at 656, 101 S.Ct. at 2871 (scientific certainty not required), also leads us to the conclusion that the Ott study, along with the other evidence, constitutes sufficiently substantial evidence to support OSHA's inclusion of pentavalent arsenic in its regulations. Similarly, the Court's directive in IUD v. API that the Secretary may rely on conservative assumptions to safeguard worker health, 448 U.S. at 656, 101 S.Ct. at 2871, supports the conclusion that, along with Ott, OSHA may use trivalent arsenic studies and conclusions to support inclusion of pentavalent arsenic in the standard. See, e.g., Environmental Defense Fund v. EPA, 598 F.2d 62, 83-85 (D.C.Cir.1978) (studies of highly chlorinated PCBs could be used to extrapolate knowledge about less chlorinated PCBs).