A radiological or nuclear (R/N) emergency may cause dozens or hundreds of mass casualties. The medical facilities in charge would likely be overwhelmed by a large number of available after at least 50 h and 74 h, making hard in this way an appropriate management of the first phase of the R/N emergency. Due to the urgency of triage decisions new tools for sorting, depending on dose, subjects exposed to radiation within the first hours after exposure are strongly needed. Biomarkers capable of measuring radiation exposure in a short time are currently available but used alone are not considered reliable because they lack specificity or sensitivity. The objective of this proposal is thus to develop a novel, fast, accurate and user-friendly tool for detecting the absorbed dose within the first hours after exposure, based on different biological mechanisms, capable to achieve the same degree of specificity and sensitivity of the established cytogenetic assays to be validated in patients treated with increasing doses of radiation for therapeutic purposes. These biomarkers were chosen because they provide the results in a few hours, they measure the radiation exposure with a dose-effect relationship, they do not need very experienced staff and complex and expensive equipment. They could hence be used in structures or in countries, which do not have the possibility to invest considerable resources for R/N emergencies. These measure genetic damage, oxidative stress and radio-sensitive proteins alteration. This choice is due to the fact that DNA is the main target of ionizing radiation, free radical damage/oxidative stress is a very early event leading to DNA damage and other genetic disorders and radiation exposure triggers alteration in the expression of specific proteins or post-translational protein modifications. Validation is done with the established micronuclei count test.This study is conducted on patients treated with irradiation of therapeutic dose (2; 3; and ≥ 5 Gy) recruited at the Regina Elena National Cancer Institute IRE-IFO in Rome (Italy) and at the Alexandria University - Main Teaching Hospital in Alexandria (Egypt).The experimental work is carried out at the ENEA Casaccia a (Rome, Italy) and in the molecular epidemiology lab of the cancer research cluster of the Alexandria University High Institute of Public Health (HIPH). Egyptian young scientists are being trained at the ENEA and IRE-IFO laboratories. In order to establish and disseminate in Egypt our running expertise the project is organized in the way to perform inter-laboratory comparison. For this reason in both countries are analysed patients submitted to the same treatment protocols. A main implementation of the proposed project will be a concrete collaboration between Italy and Egypt for building a platform for early assessing the radiation absorbed dose, to be integrated into the R/N emergencies management by the indicated End-users and possibly to other NATO countries.