The use of biomarkers to predict radiation dose and risk during space flight

During space flight, careful and complete physical measurements are made to characterize the radiation dose that is received by the astronauts. Biological changes are also evaluated in the astronauts to determine any biological changes induced by radiation during the space flight. Biological evaluations are done both before and after the space flight to ensure that the effects were induced by the space environment. These “biomarkers” have been very useful in validating the radiation doses experienced by the astronauts. There have been efforts to relate the biomarkers of dose to risk and use these changes to suggest levels of risk that the astronauts achieved as the result of the space flight. However, there are difficulties in relating radiation induced biological changes to risk and although many biomarkers are useful predictors of dose, they may not accurately predict excess risk.