April 8, 2020
EPA’s science advisors are raising concerns over the narrow scope of the agency’s draft evaluation of asbestos, prompting changes to the charge questions they will consider when they assess the draft during a peer review meeting later this month so they can formally discuss their concerns. During an April 7 conference call to discuss the draft of the charge questions that the panel will discuss at its upcoming meeting, members of EPA’s Science Advisory Committee on Chemicals (SACC) raised questions over how EPA handled background asbestos exposures and why it excluded some diseases associated with asbestos exposure in the draft. There is “not a clear indication what proportion of asbestos exposures in the workplace or community [are] covered by this [draft evaluation],” Henry Anderson, the former chief medical officer for Wisconsin and a SACC member said.
“There should be some mention of the magnitude of the comparable exposures,” he added. The SACC is slated to meet April 27-30 to peer review the agency’s draft evaluation of asbestos, which found that that multiple evaluated uses of the substance pose “unreasonable” cancer risks via inhalation exposure to workers in several industry sectors, occupational non-users and consumers. But the draft has already drawn stiff criticism from environmentalists and a key House lawmaker, who are stepping up their efforts to have Congress approve legislation banning the mineral in part because EPA’s analysis is too narrowly focused and ignores multiple aspects of asbestos risk. Chemical industry officials have also criticized the draft for overstating risks to workers. During the SACC’s preparatory meeting, Anderson and others also raised concerns that EPA had precluded some exposure pathways, such as water ingestion, or exposures to air discharges from facilities that work with asbestos. EPA’s assessment largely focuses on occupational exposures to asbestos, and a few consumer uses, and Anderson voiced concern that the assessment is “not talking about chrysotile fibers that may be in the home, in the plants, chrysotile from drinking water…”
SACC Chairman Ken Portier, a statistician retired from the American Cancer Society, reminded Anderson of EPA’s general policy to exclude from its risk evaluations any exposures or hazards that can be regulated through other statutes, or fall under the jurisdiction of other agency offices or federal agencies. “I’m familiar,” Anderson replied. “I just think that there should be some mention” of the issue. Portier said that SACC has “included that [recommendation] in the past three reviews the committee has done.” Anderson’s point was supported by another panelist, Ruthann Rudel, research director at Silent Spring Institute, who suggested adding a question to SACC’s charge asking “whether EPA has adequately described the overall opportunities for exposure and shown which ones are being addressed and which ones are not very clearly and providing a little more information about the relative importance of the things that are being addressed and the things that aren’t?” Advisors and EPA staff discussed several changes to the charge that the SACC sought to allow panelists to better address areas of concern, or areas that EPA had not addressed in the charge. A final set of charge questions is due to the panel’s designated federal official, Diana Wong, by April 13, Wong said.
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Panelist Kenny Crump, an independent statistical consultant, and others also raised concerns about how EPA handled background exposures in the draft evaluation, picking up on issues raised by public comments at the April 7 meeting. Crump noted that asbestos is a naturally-occurring mineral, can be found in high levels in dirt in some areas, particularly in western states — and that individuals exposed in EPA’s conditions of use scenarios are also exposed to these background levels of asbestos. “One of the issues that has come up with background levels and occupational exposures is the extent to which the background is additive to the occupational exposure,” Crump said. He added that any kind of construction that disturbs dirt in areas with asbestos in it could increase exposures — from home construction to new roads. “We are focused on conditions of use that we know exist and are purposeful. I get that many different [asbestos] fibers are naturally occurring. There are high levels in some background exposures, but it is not purposeful,” Louis Scarano, EPA’s chemical manager for asbestos, said of the draft TSCA evaluation, though he added that staff “spent a fair amount of time” discussing the issue in relation to the consumer conditions of use in the draft. Another panelist, Brad Van Gosen, a U.S. Geological Survey research geologist, also expressed concern with some of the exposures omitted from the draft evaluation, questioning why EPA has “limited the list to the sources you have. Consumer exposure wouldn’t just be limited to brakes…” Van Gosen urged EPA in the evaluation to be clear about why it is excluded some sources of exposure. And he noted that some asbestos exposure sources do not have clear regulatory overseers. “The natural occurrence [of asbestos] in rock or a hillside … that’s always been a gray area, who’s responsible, other than California doing it as a state,” he said. “After all these years I’m still not sure where that fits in.”
Portier said that the issue of “the extent to which ambient levels of asbestos impinge on these occupational exposures” is one that SACC has discussed with other chemical evaluations the panel has reviewed over the past year “quite often.” He encouraged the panelists to write down and remember the issues raised for the peer review meeting later in the month. “If you don’t see what you want there it’s fair game to comment on it,” he told the panelists. The comments came after one public speaker, Brett Kynoch managing director of the Environmental Information Association (EIA), a group concerned with environmental and occupational health hazards in the built environment, protested EPA’s decision to evaluate risks posed by “legacy” uses of asbestos in a separate supplemental evaluation – after the U.S. Court of Appeals for the 9th Circuit directed EPA to address such uses. “A supplement will not adequately address the exposures and concerns that are still used throughout the U.S.,” Kynoch said, adding that excluding them will underestimate cancer rates.
“The supplemental risk evaluation will do nothing if it is not integrated into the rest of the evaluation.” Another public speaker, a physician and epidemiologist, questioned EPA’s decision to exclude from the evaluation diseases other than lung cancer and mesothelioma. He urged the agency to consider pleural disease, which he said “occurs at low doses, comparable to those that would be at increased risk for malignancy … I’m suggesting it should be looked at because it could occur at lower numbers and pleural disease is something we want to avoid.” Noncancer Diseases Some panelists also appeared concerned that EPA did not consider noncancer diseases associated with asbestos exposure, with Van Gosen asking why asbestosis was not in the evaluation, prompting SACC member Holly Davies, a toxicologist with Washington state’s health department, to urge EPA to add a charge question for the panel about noncancer effects. Tom Bateston, an epidemiologist with EPA’s research office, told SACC when EPA crafted the problem formulation for the asbestos evaluation in 2018, “our initial calculations were that cancer risk would be the risk driver overall and that is why we focused on cancer. We do make mention in the draft risk evaluation that there can be risks for noncancer and that was considered in the risk determination of deaths.” EPA staff also committed to adding another question to the charge, after Davies noticed that the draft charge did not contain any questions about physical chemical properties of the asbestos, and said it “seems like there should be a question on physical chemical properties.”
Limited data on chemical properties have been an area of concern for 4/9/2020 SACC Raises Concern Over Narrow Scope Of EPA’s Draft Asbestos Analysis | InsideEPA.com https://insideepa.com/daily-news/sacc-raises-concern-over-narrow-scope-epa’s-draft-asbestos-analysis 3/3 several of SACC’s peer reviews among the first eight TSCA draft evaluations the panel has reviewed. Especially in areas with limited information, EPA has used properties to guide modeling or assumptions about hazard and toxicity. Crump agreed with Davies, particularly for a mineral like asbestos that exists in varying fiber types. “It’s important to ask whether the physical chemical properties of asbestos you’re regulating are similar to the asbestos you used [to develop the risk evaluation] … like dimensions and those kind of properties,” Crump said. Scarano committed to Portier that he would ensure a new question about properties will be added to SACC’s charge. -Maria Hegstad (email@example.com)