Cumulative Exposures and Impacts: An Overview

The issue of cumulative exposures and impacts is not a new concept in environmental justice. Rather, it is a cornerstone notion by which low-income communities and communities of color have described their everyday lived experience. For more than fifteen years, communities living in the shadow of refineries, manufacturing plants, and other major sources of pollution have recognized and documented the onslaught of multiple sources of pollution on their bodies, their families, and their communities. Further, the environmental justice movement has clearly articulated “multiple, synergistic, and cumulative impacts” to be inclusive of social and economic disenfranchisement. The disproportionate levels of pollution faced by these communities can be historically linked to a breach of civil rights and continues to be a civil rights issue.

Cumulative exposures and impacts are also not a new concept to environmentalists. The National Environmental Policy Act, signed into law in 1970, established national policy to protect the environment, created a Council on Environmental Quality (CEQ), and required that environmental impact statements be prepared for major federal actions having a significant effect on the environment. Guidelines prepared by CEQ for implementing NEPA broadly define both secondary and cumulative impacts. Secondary effects are those that are “caused by an action and are later in time or farther removed in distance but are still reasonably foreseeable” (40 CFR 1508.8). Generally, the later impacts stem from the initial action and comprise a wide variety of secondary effects such as changes in land use, water quality, economic vitality, and population density. The formal definition for cumulative effects is “impacts that result from the incremental consequences of an action when added to other past and reasonably foreseeable future actions” (40 CFR 1508.7). NEPA notes that cumulative effects of an action may at first be undetectable when viewed individually but nonetheless can multiply and eventually lead to a measurable environmental change. This important law expressed a commitment to accounting for interrelated factors.

More recently, the National Environmental Justice Advisory Council, a federal advisory committee formed by the EPA to address issues of environmental justice, convened a Cumulative Risks/Impacts Work Group. This work group grappled on a national level with the question of how to address cumulative impacts as a key to remedying environmental injustice. Key concepts forwarded in their analysis include stressors, which are not only chemicals but can be socioeconomic in nature; vulnerability, which recognizes that, “disadvantaged, underserved, and overburdened communities come to the table with pre-existing deficits both of a physical and social nature that make the effects of environmental pollution more, and in some cases unacceptably, burdensome”; community-based participatory research; proportional response, which matches community needs with an appropriate level of action; and qualitative analysis. Using these key concepts, NEJAC lays out a set of recommendations and measures for implementation by the EPA.

Locally across the country, both environmental and environmental-justice organizations have combated the tendency for an increasingly narrow definition of cumulative impacts. Regulatory agencies, entrenched in long histories of decisionmaking through risk assessment, have remained reticent to providing analyses of cumulative exposures and impacts that contain qualitative as well as quantitative analyses. Further, regulatory agencies and their scientific staff continue to try to capture the issues of cumulative exposures and impacts within a risk-assessment methodology, which is often not a tool trusted by communities who have been subject to poor decisions justified by a risk assessment.

This tension makes a recent California process to define cumulative impacts at the state level an important victory for communities. Through a three-year process to implement environmental justice in all of the boards, offices, and departments of the California Environmental Protection Agency, an advisory committee guided Cal EPA through a comprehensive process inclusive of community voices. Recently, the Advisory Committee landed on a definition of cumulative impacts for the State of California to use as it implements environmental justice. They defined cumulative impacts to mean “exposures, public health or environmental effects from the combined emissions and discharges, in a geographic area, including environmental pollution from all sources, whether single or multi-media, routinely, accidentally, or otherwise released. Impacts will take into account sensitive populations and socioeconomic factors, where applicable and to the extent data are available”. This definition provides important guidance for the Cal EPA as it begins the process of taking action to remedy environmental injustice. Additionally, communities are relieved to see a regulatory definition of cumulative impacts that takes into account their lived reality.

Urban Habitat and the Collaborative on Health and the Environment have convened a call to learn from the debate on cumulative exposures and impacts. We also see this issue as a bridge between environmental justice communities and health-affected populations as we collectively work towards healthy communities and environments.