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Risk, Uncertainty and Precaution in Science: The Threshold of the Toxicological Concern Approach in Food Toxicology

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Abstract

Environmental risk assessment is often affected by severe uncertainty. The frequently invoked precautionary principle helps to guide risk assessment and decision-making in the face of scientific uncertainty. In many contexts, however, uncertainties play a role not only in the application of scientific models but also in their development. Building on recent literature in the philosophy of science, this paper argues that precaution should be exercised at the stage when tools for risk assessment are developed as well as when they are used to inform decision-making. The relevance and consequences of this claim are discussed in the context of the threshold of the toxicological concern approach in food toxicology. I conclude that the approach does not meet the standards of an epistemic version of the precautionary principle.

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Notes

  1. Recently, some modifications to the original decision tree have been suggested. See p. 10 below.

  2. It is worth noting that Cramer et al. developed the decision tree for prioritization, not to replace actual toxicological testing. Thanks to an anonymous reviewer for this note.

  3. See Renwick (2000). For a discussion of the limitations of safety factors see Martin et al. (2013).

  4. “If the intake of a compound is estimated to be below the relevant structural class I, II or III threshold, there is a 95 % probability that the intake would be below the compound-specific health-based guidance value that would be determined if data from a chronic animal bioassay were available on the compound” (Kroes et al. 2004, p. 76).

  5. Thanks to Jan Sprenger for pointing this out to me. See also Douglas (2000, p. 569ff.).

  6. For that reason, the use of NOELs has been heavily criticised and it has been argued that NOELs neither serve as a consistent statistical norm nor as an indicator of safe concentrations of toxic chemicals (Crane and Newman 2000, p. 519).

  7. A full list of ILSI members is available at www.ilsi.org/Documents/ILSI_2013_Member_List.

  8. See for instance Canady et al. (2013) or Dewhurst and Renwick (2013). Brueschweiler (2014) is an example of an independent positive assessment of the TTC.

  9. Teratogenicity is a toxicity that induces structural or functional defects in the developing embryo.

  10. See press release at www.efsa.europa.eu/en/press/news/120424.html. See also EFSA (2015).

  11. To counter concerns about low-dose toxicity with the aim of deregulating toxic emissions, certain industry-founded scientists have brought up the concept of “hormesis”, a notion introduced by Paracelsus that refers to a beneficial low-dose effect of otherwise toxic substances. Many physiologically relevant substances, such as vitamins, show hormetic behaviour. An interesting conceptual analysis of the way in which special interest science uses and abuses scientific language in order to provide rhetorical plausibility for its claims has been carried out by Shrader-Frechette (2010). See also Douglas (2008).

  12. For further details see EFSA (2012a, b).

  13. www.ombudsman.europa.eu/en/cases/decision.faces/en/53898/html.

  14. Thanks to an anonymous reviewer for calling my attention to this.

  15. https://chemicalwatch.com/22411/dispute-over-ttc-approach-continues-at-efsawho-meeting.

  16. The Science and Environmental Health Network (1998).

  17. Steel (2015, p. 39ff.) raises concerns about Peterson’s proof and the import it is supposed to have.

  18. See Sprenger (2012, p. 885f.). For multi-model approaches and robustness in climate science see Tebaldi and Knutti (2007) and Knutti and Sedláček (2012).

  19. Steel (2011, p. 362) also highlights this fact.

  20. See also Douglas (2009).

  21. See also Steel (2011).

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Acknowledgments

I would like to thank the Food Packaging Forum in Zurich, Switzerland for giving me the opportunity to present an earlier version of this article at a TTC workshop in 2013. I would also like to thank the participants of the workshop for a lively and inspiring discussion. Large parts of this article were composed during a Visiting Fellowship at the Center for Philosophy of Science at the University of Pittsburgh in 2014. I would like to thank everybody at the Center, and in particular the director John Norton, for having created a truly inspiring and supportive work environment. My fellow Fellows Joshua Alexander, Bill Bechtel, Ingo Brigandt, Sara Green, Nicholas Jones, Raphael Scholl and Maria Serban all contributed in their own ways to a truly special intellectual experience. Four anonymous reviewers provided highly useful comments. The financial support of Society in Science—the Branco Weiss Fellowship is kindly acknowledged.

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  1. Department of Humanities, Social and Political Sciences, Swiss Federal Institute of Technology, Clausiusstrasse 49, 8092, Zurich, Switzerland

    Karim Bschir

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Bschir, K. Risk, Uncertainty and Precaution in Science: The Threshold of the Toxicological Concern Approach in Food Toxicology. Sci Eng Ethics 23, 489–508 (2017). https://doi.org/10.1007/s11948-016-9773-2

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