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Cumulative Risk and Policy


It is often surprising to people to learn that our environmental policies and regulations may not be providing equal environmental health protection for all people.  For most of its history, the US Environmental Protection Agency and state environmental regulators have evaluated the risks and health effects associated with exposures to a single pollutant in isolation. This doesn’t reflect people’s experiences. We are all exposed to multiple contaminants at once in the air we breathe, food we eat, and the consumer products we use. Single pollutant risk assessments do not reflect the reality for many communities who are over burdened with multiple sources of environmental pollution. I am presently engaged in several projects to better understand the cumulative health impacts of multiple chemical and nonchemical stressor and to devise more robust policy solutions to address these impacts.

Cumulative Risks/Impacts Policy Solutions Project

The combined effects of multiple environmental toxicants and social stressor exposures are widely recognized as important public health problems, likely contributing to health inequities. However cumulative environmental health risk and impacts have received little attention by U.S. policy makers at state and federal levels to develop comprehensive strategies to reduce these exposures, mitigate cumulative risks and prevent harm. This topic necessitates an interdisciplinary approach.

The overarching goal of the project is to identify best practices and develop solutions for cumulative risks and impacts within current legal frameworks. We will accomplish this goal through literature reviews, policy analysis and interactive workshops with participants  representing diverse perspectives and expertise (e.g., environmental health sciences, legal and policy scholars, non-governmental organizations, environmental justice advocacy and environmental regulatory agencies).Topics include lessons learned from community perspectives and from the federal and state regulatory contexts, as well as the gaps in translating the scientific evidence on cumulative and synergistic health impacts of multiple chemical exposures into policy actions. We will identify mechanisms for furthering our collaboration to accelerate progress on ameliorating cumulative risks and impacts, especially among vulnerable communities.

Specific objectives:

  • Review current landscape of cumulative risks/impacts in environmental decision-making

  • Identify opportunities to accelerate policy actions to address cumulative risk/impacts at federal, state and local levels

  • Begin to develop action steps to advance a collaborative research agenda for policy solutions

Phthalate Project

Under the 2016 Lautenberg amendments to TSCA, the agency must consider “potentially exposed or susceptible populations”, i.e., people at a higher risk of adverse effects whether by greater susceptibility or greater exposure when evaluating risk. This requirement can be best met through a cumulative risk approach. Yet the agency has not signaled that it plans to  incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, siting concerns about lack of a unified methodology or data. For this project, with support from the Environmental Defense Fund, my collaborators and I developed a CRA approach that EPA can easily implement for phthalates under TSCA. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon common adverse health outcomes among the phthalates, relevant non-chemical and other chemical stressors as an organizing principle. We present our methodology during a national webinar, EDF Cumulative Risk Assessment Framework, on September 7, 2022.

Recently Completed Projects

  1. NIEHS Career Award (K01) to evaluate the combined effects of ambient air pollution exposures and psychosocial stressors on disparities in children’s neurocognitive functioning using epidemiological and systems science modeling approaches;

  2.  A qualitative study examining the political impasse related to cumulative environmental human health risk policy in the state of Maryland using a social constructionist approach and ethnographic methods, including 35 in-depth interviews, participant observation, and content analysis of three policy proposals considered during the legislative sessions between 2014 and 2016;

  3.  A historical policy analysis of U.S. Government’s responses to growing evidence of chemical mixture-toxicity and cumulative risk, 1970 – 2017.

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