Defining and Intervening on Cumulative Environmental Neurodevelopmental Risks: Introducing a Complex Systems Approach

BACKGROUND: The combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems contributing to health inequities. However cumulative environmental health risks and impacts have received little attention from U.S. policy makers at state and federal levels to develop comprehensive strategies to reduce these exposures, mitigate cumulative risks, and prevent harm. An area for which the inherent limitations of current approaches to cumulative environmental health risks are well illustrated is children's neurodevel-opment, which exhibits dynamic complexity of multiple interdependent and causally linked factors and intergenerational effects. OBJECTIVES: We delineate how a complex systems approach, specifically system dynamics, can address shortcomings in environmental health risk assessment regarding exposures to multiple chemical and nonchemical stressors and reshape associated public policies. DISCUSSION: Systems modeling assists in the goal of solving problems by improving the mental models we use to make decisions, including regula-tory and policy decisions. In the context of disparities in children's cumulative exposure to neurodevelopmental stressors, we describe potential policy insights about the structure and behavior of the system and the types of system dynamics modeling that would be appropriate, from visual depiction (i.e., informal maps) to formal quantitative simulation models. A systems dynamics framework provides not only a language but also a set of meth-odological tools that can more easily operationalize existing multidisciplinary scientific evidence and conceptual frameworks on cumulative risks. Thus, we can arrive at more accurate diagnostic tools for children's'; environmental health inequities that take into consideration the broader social and economic environment in which children live, grow, play, and learn.

Automated summary

This study discusses the importance of the combined effects of multiple environmental toxicants and social stressors on public health, as well as the neglect of cumulative environmental health risks by current U.S. policy makers. The authors highlight how a complex systems approach like system dynamics can address shortcomings in environmental health risk assessment and reshape associated public policies.