Posted on February 4, 2021 by Lynn L. Bergeson

The Biden Administration has embraced environmental justice with unprecedented gusto. In its July 2020 Plan to Secure Environmental Justice and Equitable Economic Opportunity(Plan), the Biden Administration sets out in broad terms how it intends to use an “All-of-Government” approach to “rooting out systemic racism in our laws, policies, institutions, and hearts.”
The Toxic Substances Control Act (TSCA) is not explicitly mentioned in the Plan, but its potential utility to help achieve environmental justice is significant. Congress amended TSCA in many ways in 2016, but two provisions are especially relevant to this discussion. Congress added a requirement that, in prioritizing chemicals for risk evaluation and in conducting chemical risk evaluations, the U.S. Environmental Protection Agency (EPA) must consider whether a chemical substance presents an unreasonable risk to a “potentially exposed or susceptible subpopulation identified as relevant to the risk evaluation” by EPA.
TSCA defines “potentially exposed or susceptible subpopulation” as follows:
The term “potentially exposed or susceptible subpopulation” means a group of individuals within the general population identified by [EPA] who, due to either greater susceptibility or greater exposure, may be at greater risk than the general population of adverse health effects from exposure to a chemical substance or mixture, such as infants, children, pregnant women, workers, or the elderly.
This enumeration of subpopulations is illustrative only, and TSCA authorizes EPA to identify other subpopulations, as appropriate.
The second provision relates to risk evaluation. EPA is required under TSCA to review existing chemical substances and to conduct risk evaluations for chemicals identified as high priority. To date, EPA has selected an initial 10 chemicals for risk evaluation and an additional 20 as high-priority chemical substances for risk evaluation. EPA is in various phases of the risk evaluation and risk mitigation process for these 30 chemicals. With approximately 41,000 substances active in commerce, EPA has a long, long way to go.
Importantly, and as noted, the 2016 TSCA amendments require EPA to determine risks to subpopulations with greater susceptibility to the health effects of chemical exposures. Many would agree that the risk evaluations conducted to date, and the 2020 scoping documents for the next tranche of existing chemicals slated for evaluation, focus little on how potentially exposed or susceptible subpopulations are at increased risk from chemical exposure due to life stage, genetic polymorphisms, sex, race and ethnicity, lifestyle considerations, preexisting health conditions, nutrition, and other factors. In a few evaluations, EPA has accounted for enhanced susceptibility by applying a default interspecies uncertainty factor of 10. Detractors have noted that a 10-fold uncertainty factor can be presumed to be too small because EPA customarily uses it to account for normal expected variations in sensitivity within the healthy population. EPA has applied an uncertainty factor above 10 to susceptible subgroups in other regulatory contexts, such as to infants and children under Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) risk assessments.
No one is questioning the complexity of the risk evaluation task under TSCA. Chemical risk evaluations are demanding under the best of circumstances, and the sheer number of them required under TSCA is daunting. Importantly, however, Congress explicitly directed EPA to consider potentially exposed or susceptible subpopulations, which necessarily includes populations with unique and/or disproportionate exposure pathways, whose risk from combined exposures is likely to be underestimated, and perhaps greatly so, by more conventional risk assessment practices and assumptions. These populations include environmental justice communities, generally defined by EPAto include urban and rural poor, fence-line communities, minorities, Native Americans, and others.

Many would agree that now, as amended, TSCA offers unprecedented opportunities to help achieve environmental justice. To date, EPA has worked hard to implement the 2016 amendments, under sometimes-difficult circumstances. With the Biden Administration squarely committed to the goals of environmental justice, TSCA stakeholders all have a role to play in optimizing TSCA. Here are a few suggestions:
- Build upon the competencies of the National Health and Nutrition Examination Survey (NHANES) model to support and include community-based research on environmental justice communities that may be at higher risk;
- Task EPA’s Office of Research and Development with developing specific risk evaluation practices that more accurately reflect sensitive subpopulations, such as developing default uncertainty factors that better eliminate bias;
- Ensure that TSCA Section 6 scoping documents routinely identify fence-line exposures and related susceptible subpopulations expected to be disproportionally impacted by chemical exposures;
- Ensure that TSCA Section 6 scoping documents evaluate dietary exposure in native populations due to bioaccumulation in fish and hunted prey;
- Consider convening a “national conversation,” not unlike (but perhaps more focused than) the National Conversation on Public Health and Chemical Exposures the Centers for Disease Control and Prevention (CDC) convened in 2009-2011 identifying how TSCA and other laws can be optimized to tackle environmental health disparities;
- Utilize TSCA’s expanded Section 4 testing and Section 8 information-gathering authorities to compel testing and information reporting to inform prioritization of chemicals and the scope of risk evaluation, including testing and information relating specifically to environmental justice communities;
- Create blue-ribbon committees to prioritize the hardest questions to answer in assessing chemical exposures and risks to environmental justice communities and then answer them; and
- Utilize Risk-Screening Environmental Indicators to identify geographic areas with a high proportion of environmental justice communities that have high cumulative risk scores to identify chemical releases that might warrant review under TSCA Section 6.
A bipartisan Congress amended TSCA in 2016 and directed EPA explicitly to assess risk from chemical exposures with a view toward identifying and protecting subpopulations that may be at greater risk due to susceptibility or enhanced chemical exposure. TSCA is a powerful weapon in the fight to help in “rooting out systemic racism in our laws, policies, institutions, and hearts.” We can do better to operationalize it and eliminate fundamental inequities in chemical exposures and their assessment under TSCA.
Tags: TSCA risk evaluation, environmental justice, potential exposure, susceptible subpopulations