Biodosimetry occurs when biological samples are analyzed to detect a radiation dose someone may have been exposed to. Independent of radioactivity levels in the environment, it can be calculated directly as an alternative to estimates modeled mathematically or by computers. Probabilities of health risks are often assessed, as biodosimetry techniques can be used to determine what organs received more exposure. Immediate concerns are sometimes separated from chronic ailments that could arise in the long run, such as cancer. The concept is also used to help measure the doses of radiation during cancer treatment, and the amounts of ultraviolet (UV) light used for disinfection.
Radiation is sometimes measured from blood samples, but it can also be assessed by its presence in tooth enamel. Biodosimetry is often used to check people suspected of being exposed to a radiation source. Workers in a location where a harmful substance was released can be tested this way, as well as people near a nuclear power plant accident. Over large populations, risk is often calculated by examining people exposed to radioactivity and those not, to provide an estimate of their cancer risk.
Small samples of biological material, including blood, sweat, as well as urine and feces, can be studied with radiation biodosimetry. Exact levels of exposure can be measured as well as the expected buildup over time. Ongoing treatments for exposure can be assessed in this manner, while the units used for measurement vary depending on the exposure. For people exposed internally, the Committed Effective Dose Equivalent (CEDE) is often used, while a Total Effective Dose Equivalent (TEDE) accounts for levels of external and internal radioactive substances.
While specialists may carry instruments called dosimeters with them, most people with radiation exposure do not. Those exposed, therefore, usually do not have a way to estimate the dose received. Biodosimetry can predict the progression of radiation sickness, help find the best places to treat someone, and to determine ways to mitigate the effects of exposure. Specialists can also create local maps to estimate this exposure, which often involves using computers for visualizing data and tracking harmful radiation levels.
Biodosimetry can also be used to measure the effects of UV light on organisms. Water treatment systems often use this technique to monitor disinfection systems. Dosimeters and biological laboratory instruments are sometimes used in combination to analyze radiation. A biodosimetry assessment tool can also help determine if someone is at risk in the short term for illness, or if he or she needs to be monitored over time, perhaps over decades.