Health Experts Defend EPA IRIS on EtO Cancer Risk

Ethylene Oxide—abbreviated as EO or EtO—is one of the hazardous industrial chemicals that the Cancer Lobby is vigorously defending. The chemicals industry’s tactics include science-denial and relying on its friends in the Trump EPA. 

Now, in a strongly worded letter to EPA, scientists, medical professionals, and environmental health experts are stepping up to defend human health, scientific integrity, and public access to accurate information about hazardous chemicals. These experts—people that have devoted their professional lives to identifying preventable causes of human diseases and deaths—wrote EPA to support the findings and conclusions of the EPA Integrated Risk Information System (IRIS) program. The IRIS program produces chemical assessments, for use in regulatory determinations.

Why did these health professionals feel compelled to wade into the federal regulatory process—to defend the findings of a key EPA science program from EPA political appointees? Because the chemical industry and its Cancer Lobby, the American Chemistry Council (ACC), have long sought to gut the IRIS program, and now are succeeding, with help from Trump EPA management (see my recent blog for details).

The chemical manufacturers represented by the ACC have already tried and failed to have EPA weaken its National Air Toxics Assessment (NATA) for ethylene oxide (see ACC Request for Correction). The industry is  arguing that the IRIS assessment of ethylene oxide (EPA 2016), which forms the basis of the NATA’s cancer risk estimates, should be withdrawn, and that ethylene oxide air emissions should be more permissive—that is, more polluting (ACC, p. 6).

Playground at fenceline of petrochemical operations, Cancer Alley LA

The industry’s basic argument is that small amounts of ethylene oxide are produced during normal cellular processes, and that this is the cause of people’s cancer, instead of the almost 9 million pounds annually produced in the US to make antifreeze, polyester, PET plastic bottles, liquid coolants, solvents, agrochemicals, and other petrochemical based products. 

And, that’s why scientists stepped in—because when it comes to high quality science, these are the experts. The scientists’ letter points out that the EPA IRIS assessment is for cancer risk above background. That is, the additional cancer risk from ethylene oxide that is on top of cellular—called endogenous—levels.  Adjusting for background and endogenous levels is pretty standard stuff for scientists—for example, adjusting for smoking, age-related risks, and family or genetic risks (see details in the scientists letter to EPA). Some of you may recognize this same argument used for formaldehyde and other cancer-causing industrial chemicals that industry lobbyists and their science-for-hire experts argue are natural and therefore safe at the levels people are exposed to.

The EPA IRIS program uses standard well-accepted scientific methods to conduct rigorous, transparent, peer reviewed scientific chemical hazard assessments that are used across federal agencies, by states and local governments, and in countries around the globe to set emissions limits and clean up levels for toxic chemicals. In other words, an independent and fully functioning IRIS program is good for the public. Adherence to IRIS science recommendations helps to keep air and waterways cleaner, and people healthier.

The recent investigations of the Sterigenics facility that was emitting ethylene oxide at dangerously high levels into the Willowbrook community shows an 80% increase in Hodgkin’s lymphoma among women in the area, compared to background (see Chicago Tribune reports for details).

Ethylene oxide exposures to Cancer Alley communities in Louisiana are hundreds of times higher. EPA data identify 109 air pollution hotspots in the US where cancer risk estimates exceed the EPA trigger action level of 100 cancers per 1 million people. And, of these, 90 percent of the risk is caused by cumulative exposure to just three air pollutants: ethylene oxide, formaldehyde, and chloroprene. The top 100 air pollution ‘hot spot’ communities are spread across a number of states, including Louisiana, Pennsylvania, Colorado, West Virginia, Texas, Illinois, and Delaware (see The Intercept, A Tale of Two Toxic Cities by Sharon Lerner, Feb 2019).

Also this week, Cancer Alley communities lost their bid to get fenceline air monitoring around the chemical plants and fuel refineries that populate their neighborhoods. House Bill 175, rejected by the Louisiana House Natural Resources and Environment Committee, would have done nothing more than require more rigorous monitoring of air pollutants along the property boundary of any facility that had three or more air pollution violations over the previous two years. The chemical industry argued that monitoring could unnecessarily scare residents, and that low doses of chemicals won’t cause harm. “There may be substances that scare you, but that doesn’t mean they exceed anything,” [industry lobbyist Bob Baumann] said. “People will be frightened.” This kind of nauseatingly paternalistic statement is not only offensive to the core, it is dangerous and deadly.

Because loud music is the biggest problem at this community park, Cancer Alley LA

Environmental racism plays a leading—and deadly—role in where polluting industries are located, how they are concentrated, and whether they are compliant with regulations. Non-whites and below-poverty individuals are more likely to reside near polluting industrial facilities, and a recent study reports that the racial correlation is stronger than the economic one (Mikati et al 2018). In other words, siting polluting industrial facilities is both racist and classist, but mostly racist. This emphasizes the importance of EPA addressing the health risks from cumulative exposure to multiple chemicals, across multiple industrial sectors that impact local areas.

The IRIS assessment supported in the scientists’ letter recognized the importance of developing a health risk value that is protective of children, especially the most vulnerable children in our country: children who live in low-income communities and communities of color.

The chemical industry and its Cancer Lobby, the American Chemistry Council (ACC), have long sought to gut the IRIS program (see my blogs here and here). Instead of addressing the industrial sources of its air pollution, the chemical industry and its allies at the TSCA program are attacking the IRIS assessments, scavenging off IRIS resources to staff up the industry-captured TSCA program (GAO 2019), and shifting the balance of the Agency’s Science Advisory Board from non-industry to industry members.

More scientists and health professionals need to speak out against false science and rollback of regulatory safeguards that will lead to increased human disease and death.

If you want to learn more about how corporate tax giveaways make Louisiana petrochemical industries wealthy, lawmakers captured, and citizens poor, check out this graphic video called, "Why Louisiana Stays Poor".

About the Authors

Jennifer Sass

Senior Scientist, Federal Toxics, Health and Food, Healthy People & Thriving Communities Program

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