Biomarkers of Exposure and Responses to Ionizing Radiation

Abstract The health effects of ionizing radiation from external sources and internally deposited radionuclides have been more extensively studied than any other hazardous agent. The health effects are of both a deterministic (threshold) and stochastic (linear, no-threshold dose–response) form, such as cancer. The most important late-occurring radiation-attributable response is cancer, even though radiation is actually a relatively weak carcinogen. The most useful research findings on radiation are those incorporated into a source-intake-tissue dose–health response paradigm. Numerous useful biomarkers of exposure and dose exist for radiation and radionuclides. Biomarkers of effect have been identified and used for the acute radiation syndrome. Development of biomarkers of radiation-induced cancer has proved challenging because human cancers occur frequently and have multiple causes. Society-at-large will gain the greatest future benefits from research that focuses on biomarkers of cancer, without regard to the specific causative factors or agents.