1. I recognise the practical advantages of the LNT assumption in the practice of radiation protection, but the assessment of risks should acknowledge the possibility that there is no risk to health from low doses of ionising radiation. 2. Estimates of risk should be made only for individuals who receive more than - · 50 mSv as a single, acute dose, or · 100 mSv in a year from all sources, or · 1000 mSv in a lifetime, in addition to natural background. Below these doses, risk estimates should not be used. 3. Collective dose should not be used as an absolute measure of risk for populations in which individuals receive lifetime doses of less than 1000 mSv above background, or less than 100 mSv in a year, or less than 50 mSv in a single event. The above conclusions are drawn from scientifically based information on the biological effects of radiation. A document outlining the rationale for them has been provided to Jack Valentin. Don Higson