Introduction

The present issue of the BELLE Newsletter was designed to explore the concept of adaptive response with particular emphasis on radiation and its relationship to the concept of hormesis. In order to facilitate a consistent and focused assessment of this issue a number of internationally recognized experts with knowledge of both adaptive response and hormesis were invited to provide an independent assessment of the five questions listed below. After the responses were received Professor Charles A. Waldren of Colorado State University provided a summary of the invited expert commentaries. His summary is provided at the end of this issue of the BELLE Newsletter.

Questions Responded To:

• 1. How does the dose that induces the adaptive response (AR) relate to human and environmental (ecological) exposures?
• 2. What are the potential up and down sides of having one's AR induced?
• 3. Can the induction of AR be manipulated for medical and other benefits?
• 4. How does the AR relate to the concept of hormesis?
• 5. Should knowledge of the AR affect current risk assessment methods for carcinogens?