EPA ignoring major risks in chemical assessments

1,4-dioxane is a cancer-causing chemical contaminating drinking water in Michigan, a situation local officials are calling “a slow-motion environmental disaster,” and significant problem with the water supply. Yet, despite such clear and acknowledged dangers, EPA will ignore 1,4-dioxane in people’s drinking water entirely in its health risk evaluation under the Toxic Substances Control Act (TSCA). In fact, EPA is ignoring all 1,4-dioxane exposures to the general public and only assessing occupational exposures (workers). This will obviously underestimate the risk to the public.

Unfortunately, the problems with EPA evaluations are not confined to 1,4-dioxane or inadequate exposure assessment.  EPA’s piecemeal approach to chemical risks is apparent in its plans for all the first 10 chemicals under TSCA evaluation (shown in the image below). From the Agency’s exposure assessment, to consideration of vulnerable populations, to what data are informing the assessments (or lack of data)— EPA’s plans do not follow current scientific principles or the mandates of TSCA, with ultimate results that will impact the public’s health.

Fig 1
The first 10 chemicals have a combined production volume of over 1 billion pounds a year; they are added to our everyday products and building materials

When chemical risks go ignored and unaddressed, communities can suffer—as in Johnson County, Indiana where a toxic plume of the cancer-causing chemical trichloroethylene (TCE) is suspected in a cluster of rare and tragic children’s cancers. TCE is one of the first 10 TSCA chemicals, and EPA plans to ignore air and water contamination in its evaluation—completely leaving out children like those in Johnson County.

Amended TSCA gives EPA clear direction for conducting risk evaluations: to comprehensively consider how a chemical might harm health (its hazards) together with how people (such as workers, children, communities) come in contact with the chemical (its uses and exposures), put all this information together to assess the levels of risk, and then decide whether or not these risks are unreasonable.

Additionally, in its evaluation, EPA must explicitly consider groups called susceptible sub-populations who are at greater risk of harm from the chemical because they have higher exposures and/ or greater vulnerability to its toxic effects. For example, the developing fetus and children are often more susceptible to chemical harm than an adult, as seen with TCE. In addition to being a carcinogen, prenatal exposures are linked to increased risk of birth defects affecting the heart—and these effects occur with even lower exposures than the other health effects.

The figure below shows the TSCA process for the first 10 chemicals. EPA described what it plans to do for each element of the risk evaluation (hazards, uses, exposures, susceptible sub-populations) in the scoping and problem formulation documents in 2017 and 2018. Leading scientists and clinicians pointed out major scientific flaws in EPA’s assessment plans in comments to the Agency.

EPA’s final risk determination and risk management rules block any further action on that chemical by states (preemption).

We are now at the draft risk evaluation stage, and the first chemical out of the gate- pigment violet 29– gives an idea of how EPA will likely proceed with the other 9 risk evaluations. In our previous comments to EPA, we explicitly noted that the Agency lacks sufficient information to make a determination on this chemical—see more about the issue of adequate information in our blog here. But EPA made no fundamental changes from the problem formulation in how it is assessing risks, and inappropriately concluded that pigment violet 29 does not pose an unreasonable risk.

If the pigment violet 29 draft risk assessment is any indication, EPA will likely stick with its flawed approach for the rest of the chemicals too– despite numerous public comments criticizing the scientific, technical and legal basis of the Agency’s approaches. Sadly, the public is the one with the most to lose from this bad science, especially children and our most vulnerable communities.

About the Author

Veena Singla, PhD is a Senior Scientist in the Healthy People & Thriving Communities program at Natural Resources Defense Council. Prior to that, she was the Associate Director of Science & Policy at PRHE.