CommentaryStrengthening the foundation of next generation risk assessment

- US EPA evaluated role of new toxicity testing methods and interpretation in risk assessment in draft NexGen report.
- New methods offer exciting opportunities for advancing the field.
- Substantial additional research is needed before they can be used reliably in risk assessment.
- US EPA should more fully consider data quality, data relevance, and adversity of effects.
- We illustrate these concerns with a critique of the report's prototype ozone evaluation.

In a recent draft report, Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology, the US Environmental Protection Agency presents valuable contributions to understanding the roles that evolving toxicity testing methods and associated interpretative techniques can play in assessing the risks associated with chemical exposures. However, the evaluations presented in the NexGen report would benefit from more thorough consideration of several essential components of a critical review of toxicity data, e.g., data quality, data relevance, and the extent to which the test endpoints reflect adverse effects. Such considerations are necessary to ensure that the NexGen report evaluations - and the resulting conclusions and recommendations - are grounded in scientifically sound, representative data reviews. We illustrate these concerns with a critique of the report's prototype ozone evaluation. Although substantial additional research is needed before new toxicity data types can be used reliably in rigorous risk assessment applications, they clearly offer exciting opportunities for advancing toxicological science and risk assessment. By explicitly identifying limitations still to be addressed and providing stronger guideposts for future research needs, the NexGen report could serve an influential role in achieving the promise of these new research approaches.