Comments to the foundation document: “Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation: A Summary of Judgements for the Purposes of Radiological Protection of Humans”. As a whole, it is a valuable document which assembles and clearly summarizes the gain of knowledge since 1990 on the health effects of low dose radiation exposure. Although all the subjects reported in the document have already been addressed in previous ICRP documents, we consider it was important to compile all of them in a single report. There are some comments to the document: 1. The “Principal Conclusions and Proposals of the Task Group” included at the beginning of the document, clearly summarize and conclude on main topics essential for radiological protection. Some important statements are made about some subjects not entirely clear to date, i.e. the relevance of epigenetic effects (genomic instability and bystander effects) or adaptive response in the actual system of radiological protection. It would be valuable to have in addition a short summary (not more than 6-7 pages) of the document contents, for persons working in radiation protection matters who are not experts in this particular subject. 2. Although several tables are provided about the cancer mortality/incidence rates for different populations, ages at exposure and sexes, we miss the inclusion of a table with the excess lifetime cancer risks due to radiation, as a function of age and sex (similar to table B-9 in ICRP-60). 3. When significant changes from ICRP-60 are presented, it will be useful to include in the conclusions, or in the suggested additional summary, the main reason(s) for such changes, i.e. detriment values and tissue weighting factor for breast cancer; probability coefficients for hereditary diseases. 4. In spite of having data suggesting that the lens of the eye can get damaged with doses below the dose limits for this organ (in 1984 this was already suggested), the document does not mention if these data together with other recent scientific reports could lead to changes in the present dose limits for the lens of the eye. 5. One of the conclusions stated is that ”DDREF of 2 recommended in Publication 60 should be retained for radiological protection purposes”. For medical practices, it would be very important to have guidance about which DDREFs should be used when patients are exposed to moderate or high dose-rates. 6. Since the IARC study on risk estimates in nuclear workers has just been published in The British Medical Journal (9 July 2005), the results/conclusions reached should be included in the document. 7. It will be very useful to include a Glossary of the main terms used in the document.