UBC Theses and Dissertations

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UBC Theses and Dissertations

Chemical controversy : exploring scientific disagreement around endocrine disrupting chemicals McIlroy-Young, Bronwyn


Jurisdictions around the world are currently developing regulation to manage endocrine disruptors (EDs)–substances that have the potential to disrupt the hormonal system–but the scientific community is divided over what regulatory approach is best supported by science. Some ED scientists support a hazard-based approach, which restricts substances based on their potential to cause an adverse health effect. Others support a risk-assessment approach, which assesses the likelihood of real-world exposure at a harmful dose. The typical response to scientific controversy is to call for more research with the aim of clarifying facts and achieving consensus. However, this approach is rarely successful in complex fields surrounded by uncertainties, potentially because it ignores value-related and cultural differences between sides, which commonly underlie controversy in policy-relevant fields. This exploratory thesis aims to describe the modes of thinking characteristic of hazard and risk scientists. To address this, two focus groups were conducted with hazard and risk scientists whose work informs environmental ED regulation. The focus groups were analyzed using an empathetic and symmetrical approach centering around dominant narratives about ED research and regulation. The analysis found starkly contrasting narratives: the hazard story was about the insurmountable complexity and uncertainty of environmental problems, and industry influence on regulation; the risk story was about barriers to efficient and effective science-policy processes. The narratives were supported by different framings of EDs and different archetypes of science-policy actors. The archetypes from the two sides functioned as tools in a boundary struggle over the definition of good science for use in ED regulation: each story highlights the biases of the disputing side and asserts their sides’ epistemic authority. The dispute has broad ramifications: certain hazard scientists view ED research as an early step in a paradigmatic shift in regulatory toxicology. In line with Knorr-Centina, I conclude that although the hazard and risk approaches are incommensurable; each adds distinct epistemic value to regulatory research on EDs. In concordance with other studies, this conclusion reveals a need to revise science-policy processes so as to leverage a plurality of sciences. Dialogue and increased transparency are suggested as next steps towards this goal.

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