Response to Comments by Caldwell et al. on Article “Applying Mode-of-Action and Pharmacokinetic Considerations in Contemporary Cancer Risk Assessments: An Example with Trichloroethylene”

Abstract

have criticized our article in this journal (), in which we attempted to demonstrate how mode-of-action and pharmacokinetic considerations could be applied in a cancer risk assessment for trichloroethylene. This short response provides us the opportunity to endorse, without reservations, our earlier conclusions about a mode of action-based cancer risk assessment approach for trichloroethylene. Our comments here also note the continuing reluctance of regulators to embrace widely-held scientific consensus positions on mode of action rather than to maintain a regulatory bias requiring proof that no other mode-of-action could be operative—an impossible hurdle in any assessment. We remain concerned that policy and precautionary decisions rather than any true regard for the body of scientific research are likely to drive the US EPA risk assessment for TCE, and perhaps for most other animal carcinogens, despite research to clarify mode of action and tissue dosimetry considerations.

Key words :

• Cancer Risk Assessment
• Mode of Action
• Pharmacokinetics
• Trichloroethylene