Chromosome Dosimetry

The HPA provides a specialist biological dosimetry service to evaluate people known or suspected of being overexposed to ionising radiation. It is based on analysing chromosome damage in blood cells.

The method can:

• demonstrate false alarms when, for example, the dose recorded on a badge was not really received by the wearer.
• confirm genuine overexposures and provide an alternative estimate of dose independent of the physics methods.
• often be the only available method to confirm or refute suspected overexposure to people in a radiation incident who were not wearing dosemeter badges.

The standard chromosome test provided is the dicentric assay, which can indicate a recent radiation exposure that occurred within about 2 years. Cells carrying dicentric chromosome damage are unstable and they are eliminated from the blood being replaced by undamaged cells. A chromosome test more suited to indicating an old radiation exposure is called Fluorescence In Situ Hybridisation (FISH). The test detects stable radiation induced chromosome translocations and can be used to assess total lifetime radiation dose.

The service is free to customers who have contracted the HPA to be their Radiation Protection Adviser. Otherwise the charge per analysis (with effect from April 2009) is £420.00 (+ VAT in the UK) for the standard dicentric assay and £700.00 (+ VAT in the UK) for the FISH translocation assay.

Blood samples for analysis may be sent to the Centre for Radiation, Chemical and Environmental Hazards at Chilton from anywhere in the world. Exact details of what, when and how to dispatch are available on request.

We prefer to liaise with the appropriate physician and firstly to discuss the specific circumstances of each case to establish whether it is appropriate for chromosome analysis to be carried out.

If you are interested, please email CHI-Cytogenetics@hpa.org.uk.

Publications

The following chromosome publications from HPA staff may be of interest:

• Moquet J E, Edwards A A, Lloyd, D C and Hone, P. The use of FISH chromosome painting for assessment of old doses of ionising radiation. Radiation Protection Dosimetry, 88, 27-33 (2000).
• Lloyd D C, Edwards A A, Moquet, J E and Guerrero-Carbajal, Y C. The role of cytogenetics in early triage of radiation casualties. Applied Radiation and Isotopes, 52, 1107-12 (2000).
• Lloyd D C. New developments in chromosomal analysis for biological dosimetry. Radiation Protection Dosimetry, 77, 33-6 (1998).
• Lloyd D C. Chromosomal analysis to assess radiation dose. In: Radiation Injury and the Chernobyl Catastrophe, Stem Cells, 15 (suppl 2), 195-201 (1997).
• Voisin P, Roy L, Hone P, Edwards A, Lloyd D et al. Criticality accident dosimetry by chromosomal analysis. Radiation Protection Dosimetry 110, 443-447, (2004).
• Edwards A A. The use of chromosomal aberrations in human lymphocytes for biological dosimetry. Radiation Research, 148 (suppl), S39-44 (1997).
• Lloyd D C, Edwards A A, Moquet,J E, Hone P A and Szluinska, M . Doses in radiation accidents investigated by chromosome aberration analysis XXIV. Review of cases investigated 2003-2005. Chilton, HPA-RPD-012 (2006).
• Sevankaev A, Lloyd D, Edwards A et al. Cytogenetic investigations of serious overexposures to an industrial gamma radiography source. Radiation Protection Dosimetry, 102, 201-206 (2002).