PRESENTATION The World Council of Nuclear Workers has a deep interest in radiation protection and in the assessment of the hazards associated with the biological effects of low and very low doses of ionizing radiation. Therefore, we are very much concerned by the controversies which have arisen over the past few years with regard to the dose limit and the LNT assessment of the risks associated with exposure to low and very low doses of radiation. Accurate knowledge about low level radiation exposures is of major importance for the future of medical imaging and environmental radiation protection. It also contributes to the debate about future world energy options. Two pitfalls must be avoided: fuelling unjustified anxiety on doubtful bases or underestimating the risks associated with exposure to ionizing radiation. Only independent and careful research can lead to answers. Only effective communication of this research to stakeholders can make a practical difference. This is why the World Council of Nuclear Workers and LOWRAD are holding every two years an international conference on “The effects of low and very low doses of ionizing radiation on human health”. During the conference the floor is given to both proponents and opponents of the linear no threshold relationship, the effect of dose rate, DNA repair mechanisms, and new indirect effects such as genomic instability and bystander effects will be discussed. The aim of the meeting is to clarify the problems, to assess the uncertainty of the various risk assessments and to analyse the scientific ways through which these uncertainties could be reduced, to present and discuss the latest research results concerning the health effects of exposure of humans and other living organisms to low and very low doses of ionizing radiation. The conference aims to present state-of-the-art scientific research from leading experts in the field and to make the findings accessible to specialists and non-specialists who work with or are otherwise concerned about low dose exposures. Main speakers from academic institutions will present basic scientific results and will be joined by regulators, clinicians and health physicists, whose job it is to interpret the basic science and formulate and implement protection policy for individuals exposed during their work, in their environment or as a result of medical treatments. There is an open call for submitted papers and posters and young scientists and interested non-specialists are especially encouraged to present posters or short talks to the conference. Selected papers presented at the conferences are published in the International Journal of Low Radiation MAINS TOPICS Radiation risks in perspective, .Radio-induced cancer among cancer risks, .Epidemiological Data, .Effect of radiation on radiation workers, .Medical cohorts, .Models and controversies in radiation carcinogenesis, .The effects of radiation on mammalian cells and the stress responses in cells and tissues, .Variations in natural background irradiation throughout the world : from 1 to 100 mSv/year, .Review of Radiation Exposure limits - world wide, .Radiation protection, .Hormesis, .Genomic instability, .Bystander effects .Changing paradigms and radiation protection, .Impact of low dose/dose rates on DNA repair/disrepair, .Transgenerational effects, .Low doses irradiation and immune response, .Genetive predispositon, .Constitutive and induced repair, .Facilities and tools for studying low dose repairs.