Are Cumulative Assessments Meeting the Needs of EJ?

The public’s attention to environmental justice has refocused the U.S. Environmental Protection Agency (EPA) on cumulative assessment of risk and impacts. Concordantly, EPA recently finalized its Fiscal Year 2022–2026 Strategic Plan, which includes a new foundational principle of advancing environmental justice and civil rights in its programs, policies, and activities to achieve the agency’s mission of protecting human health and the environment. Are you ready?

Conventional human health risk assessment, as conducted under state and federal environmental statutes like the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA), excludes many factors that contribute to cumulative adverse health outcomes. Risk assessment under these statutes supports risk management decision-making, but considers neither the cumulative effects of chemical and nonchemical stressors nor the differences in vulnerability and susceptibility among populations with differing socioeconomic status and other risk modifiers.

Cumulative risk assessment (CRA) and cumulative impact assessment (CIA) both consider multiple types of exposures, and can therefore represent exposures and risks to populations more accurately than can conventional risk assessment. CRA and CIA are the primary alternative frameworks to the current conventional paradigm for risk assessments; however, risk assessors and managers have yet to establish best practices, which greatly hinders the application of these frameworks.

Despite the numerous papers available on both CRA and CIA, little has been written on the similarities and differences between the two. EPA describes cumulative risk as “the combined risks from aggregate exposures to multiple agents or stressors” (USEPA 2003) and cumulative impact as “the total burden—positive, neutral, or negative—from chemical and non-chemical stressors and their interactions that affect the health, well-being, and quality of life of an individual, community, or population at a given point in time or over a period of time” (USEPA Science Advisory Board 2022). Although both CRA and CIA assess health outcomes, one major difference is that CRA uses hypothetical scenarios to evaluate causality and long-term effects in terms of health as a single outcome, whereas CIA focuses on near-term alternatives for assessing impacts to affected communities, and not just health outcomes, but also by examining risks across multiple dimensions of well-being and quality of life.

EPA is currently updating its CRA guidance, which was last issued in 2003. The 2003 version prompted few changes to the way that risk assessments were conducted. The latest update to that guidance has yet to be released to the public, though it has undergone independent contractor-led review (Inside EPA). It is not clear, therefore, how the updated guidance will shape future risk assessments and environmental justice-related initiatives.

EPA recently asked its Science Advisory Board to provide insight into the state of the science for supporting CIA, relative to President Biden’s 2021 Executive Orders 13985 and 14008 to advance racial equity and address the climate crisis. EPA’s Office of Research and Development published a white paper in January 2022 on cumulative impacts. This ambitious white paper highlights CIA as the process of accounting for cumulative impacts in the context of problem identification and decision-making. It also identifies gaps and limitations in implementing CIA and provides recommendations for advancing such analyses for decision-making frameworks, including rulemaking, permitting, and enforcement.

Although both CRA and CIA have been used in regulatory analysis, they have yet to be applied extensively and in a meaningful way to address environmental justice concerns. It will be imperative that risk assessors and managers remain aware and responsive to updates to the tools, methods, and data sources that EPA has been working on. We anticipate that new guidance on cumulative assessments will intensify early planning stages and influence outcomes related to enforcement and permitting. For instance, incorporating increased engagement with communities having environmental justice concerns will be essential to monitoring and determining the best strategies for improving long-term community well-being, quality of life, and resiliency. A strong engagement plan involving the communities, regulators, and responsible parties can focus on risk communication tools and ensure that all stakeholders are heard. Furthermore, CIAs and CRAs require more extensive data than conventional risk assessment to adequately characterize chemical and nonchemical stressors, sources of stressors, past exposures, and mitigating factors. And even if such data are readily available, interpreting the data for decision-making may pose challenges.

The scientific community (e.g., 2021 SETAC North America conference) has discussed approaches to addressing cumulative risk and impacts, such as incorporating 1) biological and physiological risk modifiers to vulnerable populations (i.e., intrinsic risk modifiers); 2) nonchemical risk modifiers (e.g., psychosocial effects) that can influence susceptibility; and 3) epidemiological data. The path to completing research and determining the best methods, however, seems never-ending—intensely data-driven but often lacking linkage to actual decision-making. It is important to continue gathering and analyzing data on the components of CRA and CIA, but given the urgency of addressing environmental justice issues, risk assessors and managers must not suffer from analysis paralysis. We need to pivot from ideology to practice—namely by using CIA or CRA even if methods have yet to be perfected—when people’s future well-being is at stake. It will therefore be critical that future guidance describe how new information should be used and under what circumstances.

It also remains unclear how and where in the regulatory lifecycle cumulative impacts will be addressed. Though permitting of new facilities is a clear opportunity to consider cumulative impacts, communities have good reason to focus on the cumulative impacts of already existing (i.e., previously permitted) facilities. One potential opportunity for consideration of cumulative impacts relates to natural resource damage assessment (NRDA). Many NRDAs identify compensatory restoration projects as a means of “making the public whole” for the lost use of natural resources as a result of a historical release. The differential value of such restoration projects to communities that are overburdened versus less burdened can be quantified and accounted for in the development of such projects, to incentivize greater investment in open space and recreational resources in overburdened communities (Tomasi 2022).

In conclusion, approaches to cumulative assessments are rapidly adapting to address environmental justice concerns, incorporating new science and methodologies, and facilitating environmental decision-making. Both CRA and CIA provide opportunities to go beyond conventional risk assessment and bring the potential for wide-reaching outcomes related to the health and well-being of communities. Though CRA seems to have a longer history than CIA, CIA is likely to permeate the broader risk assessment field because of its applicability to addressing environmental justice issues (USEPA Science Advisory Board 2022). Progress has been made in recent years to bring these analyses to the forefront of risk assessment, but more clarity and consensus are needed on how and when each framework should be applied before risk assessors and managers can adequately implement cumulative assessments. Readers are urged to watch for the release of EPA’s updated CRA guidance and to begin working within its framework from the outset.