Opinion ID: 588800
Heading Depth: 2
Heading Rank: 5

Heading: Regulation of EDB

Text: 48 The compound EDB is used both as a pesticide and as an additive in leaded gasoline. The EPA banned EDB as a pesticide in 1983 and regulates its use in leaded gasoline. The EPA discussed EDB in 1985, proposing an MCLG of zero based on available data indicat[ing] that EDB has carcinogenic effects in animals. 1985 Proposed Rule, 50 Fed.Reg. at 46,996. The EPA reiterated this position in the 1989 Proposed Rule: EPA believes that the available data are adequate to classify EDB in Group B2, probable human carcinogen and therefore an MCLG of zero is appropriate. Proposed Rule, 54 Fed.Reg. at 22,086. The Final Rule established an MCLG of zero and an MCL of 0.00005 mg/l for EDB. Final Rule, 56 Fed.Reg. at 3,528 (Table 3).
49 Dow challenges the MCLG and MCL for EDB on the grounds that the EPA both failed to address the comments submitted on EDB and improperly rejected material contained in those comments. Dow complains that the EPA failed to consider a human epidemiological study conducted by Professor M.G. Ott in 1980 and submitted by the CMA in 1986. See Comments of CMA (Apr. 14, 1986) at 5-6, 9, reprinted in J.A. at 1053-54, 1057. The Ott study investigated the experience of 156 male workers exposed to EDB (primarily through inhalation) in manufacturing facilities. See EPA Drinking Water Criteria Document for EDB (July 1987) at VI-2, reprinted in J.A. at 1702. Contrary to Dow's assertions, the EPA specifically analyzed and responded to the Ott study, concluding that 50 the results should be regarded as equivocal because interpretation is complicated by the small population size, poorly characterized exposure concentrations, and concomitant exposure to numerous other chemicals. 51 Id. at VI-4, reprinted in J.A. at 1704. Furthermore, the EPA did not stop with Ott's work. See id. at VI-4 to VI-10, reprinted in J.A. at 1704-10. After reviewing additional epidemiological studies of the effects of EDB on humans, the EPA summarized its findings: 52 Mortality studies conducted on workers exposed to EDB are inconclusive with respect to cancer risk or death by other specific target organ effects (Ott et al., 1980; Turner, 1976, 1977). Because of limitations of scope and design, these epidemiologic studies are not considered to provide definitive results. In particular, small cohort size and lack of, or poorly characterized, exposure estimates are serious drawbacks. 53 Id. at VI-10, reprinted in J.A. at 1710. 54 Thus, it is simply untrue that the EPA failed to consider the available human epidemiological data. Not only did it respond to the Ott study that Dow claims it ignored, it also analyzed other epidemiological data that Dow itself now ignores. Moreover, as with DBCP, we note that these studies involved exposure primarily through inhalation, not ingestion, and that the EPA has cautioned that inhalation data should not be relied upon in a risk assessment for oral exposure. EPA, Response Document at 4-127, reprinted in J.A. at 1104. We find no basis for concluding that the EPA had ignored the epidemiological data on EDB. 55 Dow also asserts that the EPA failed to address and improperly rejected alternative risk assessments of EDB. The comments including the alternative risk assessments were directed against the EPA's proposal to establish the MCLG at zero. See Comments of CMA at 5-9, reprinted in J.A. at 1053-57. In essence, then, these studies were used to support petitioners' general argument that there are safe threshold levels for carcinogens. The EPA responded to the alternative risk assessments by reiterating that there is no safe threshold for carcinogenic substances. See EPA, Response Document at 4-154 to 4-155, reprinted in J.A. at 1112-13. As discussed above, the EPA has adequately explained its no-threshold position on carcinogenic substances. 56 Finally, Dow alleges that it appears that the EPA ignored all relevant scientific information on EDB's carcinogenicity and instead simply set the MCL as a multiple of the lowest detection limit for EDB. The record, however, provides evidence that the EPA relied not only on EDB's detectibility but also on its assessment of (1) the best available technology (BAT) for removing EDB, Final Rule, 56 Fed.Reg. at 3,556; (2) the feasibility (including costs) of the BAT for EDB, id.; and (3) the carcinogenic risks of EDB, Comment/Response Document on 1989 Proposed Rule at 9-16, reprinted in J.A. at 1466. We therefore cannot accept Dow's final argument that the rule bears little if any relationship to the record. 57