- Internal dosimetry
Internal dosimetry provides methods for calculation of
radiation dose and risks from radionuclides incorporated inside human body. [ [http://rpd.oxfordjournals.org/cgi/content/full/127/1-4/1 Internal Dosimetry of radionuclides ] ] The Radionuclide deposited in human body will irradiate that person and will give dose to body until excreted or completely decayed from the body.
Routes of intake
There are three routes of intake (of radionuclide) namely,
*Inhalation
*Ingestion
*InjectionInhalation is the most prominent route of intake. In radioactive area radionuclide particulate may be suspended in air and can enter body by inhalation. These particulates may be deposited in different parts of respiratory tract depending upon theiraerodynamic diameter . [ [http://www.epa.gov/apti/bces/module3/diameter/diameter.htm Aerodynamic diameter ] ] Monitoring techniques
In-vivo monitoring
Internal dose monitoring of the radionuclides which emit radiation which can penetrate out of the body.For example X-rays, gamma rays of sufficient energy.Monitoring Systems
Whole Body CounterA
Whole Body Counter [ [http://www.hc-sc.gc.ca/ed-ud/pubs/newsletter-bulletin-1/whole_body-corps_entier-eng.php Whole Body Monitoring ] ] has a low background arrangement with counting systems
*NaI(Tl) detectors for high energy photon detection
*Phoswich detectors with Be window and thin NaI(Tl)crystal and thick CsI(Tl)or CsI(Na), for low energy (<100 keV) photon detectionNowadays HPGe detectors are replacing detectors for measuring the low energy and high energy photons with appropriate electronic systems.
Calibration of these systems is carried out with different type of physical and mathematical phantoms. Among physical phantoms areBOMAB ,LLNL,JAERI,thyroid and the knee phantoms. Some of the renowned mathematical phantoms are MIRD, CRISTY and nowadays voxel phantoms.
In-vitro monitoring
Monitoring of the radionuclides present in the body using the bio-assay sample taken out of the body.For example urine sample,sweat, fecal sample etc.References
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