Biological Retrospective Dosimetry

At low doses of radiation exposures such as below 200 mSv, no serious biological effects are expected. For regulation of radiation exposure and to avoid serious unwanted exposures, dose limits are set well below the observable thresholds of biological effects. When a suspected exposure is notified, it is mandatory to investigate and confirm the genuineness of such incidents. Physical parameters such as dose rate measurements, tracing the events with possibly available passive or active dosimeters and many other investigations will help to get an idea of possible levels of exposures. However, exact recreation of events is not only feasible but also lead to erroneous conclusions in most cases. It becomes necessary to rely upon reliable indicators of radiation exposure to ascertain genuineness, estimate and indicate the level of exposures in such events. Over the decades, many advances in Biodosimetry assay have helped to independently assess such exposures by measuring biological dose. Depending on exposure scenarios, multi-parametric approach of selecting set of biological indicators will help to assess the biological dose. Many advanced cytogenetic and molecular methods have helped to address the challenges of such assessment. Biodosimetry assays are the only methods available for ascertaining and estimating biological dose for suspected over-exposures and radiological emergency situations. These methods also play a major role in medical management and triage. In the eventuality of a radiological emergency, it becomes inevitable to provide care for exposed individuals. However, large numbers of unexposed individuals or individuals with clinically insignificant doses are to be screened off for effective medical management of those who really need specialized medical attention. Depending on exposure scenarios, a multi-parametric approach of selecting a set of biological indicators will help to assess the biological dose. Many advanced cytogenetic and molecular methods have helped to address the challenges of such assessment.