Tools for Addressing Cumulative Impacts on Human Health and the Environment

Abstract

"Cumulative impacts" refers to the total harm to human health and the environment resulting from combinations of stressors over time. Cumulative impacts are creating three kinds of effects: degraded ecosystems (such as oceans and boreal forests), human diseases, and disproportionately burdened communities, which are the hallmark of environmental injustice. At the heart of the problem lie the modern risk-based regulatory systems of the U.S. and Europe, which are not designed to understand or manage cumulative impacts, and which have permitted an accumulation of harmful activities and effects. Alternative, precautionary regulatory approaches have been recommended but not yet widely implemented. Now some communities, planners and regulators are finding ways to supplement traditional risk-based approaches, using innovative new tools for assessment and decision-making in the face of cumulative impacts, including indexes, mapping, and screening. These efforts both inform policy and serve as exemplary models. Together they point the way toward new, precautionary decision structures aimed at reducing cumulative impacts.