title: Biomarkers specific to densely-ionising (high LET) radiations.
abstract: There have been several suggestions of biomarkers that are specific to high LET radiation. Such a biomarker could significantly increase the power of epidemiological studies of individuals exposed to densely-ionising radiations such as alpha particles (e.g. radon, plutonium workers, individuals exposed to depleted uranium) or neutrons (e.g. radiation workers, airline personnel. We discuss here a potentially powerful high LET biomarker (the H value) which is the ratio of induced inter-chromosomal aberrations to intra-arm aberrations. Both theoretical and experimental studies have suggested that this ratio should differ by a factor of about three between high LET radiation and any other likely clastogen, and will yield more discrimination than the previously suggested F value (ratio of inter-chromosomal aberrations to intra-chromosomal inter-arm aberrations). Evidence of the long-term stability of such chromosomal biomarkers has also been generated. Because these stable intra-arm anld inter-chromosomal aberrations are (1) frequent and (2) measurable at long times after exposure, this H value appears to be a practical biomarker of high LET exposure, and several in vitro studies have confirmed the approach for unstable aberrations. The approach is currently being tested in a population of Russian radiation workers exposed several decades ago to high- or low LET radiation.
authors.affiliation: Center for Radiological Research, Columbia University 630 West 168th Street, New York, NY 10032, USA. djb3@columbia.edu
authors.forename: D J
authors.initials: DJ
authors.lastname: Brenner
authors.forename: N
authors.initials: N
authors.lastname: Okladnikova
authors.forename: P
authors.initials: P
authors.lastname: Hande
authors.forename: L
authors.initials: L
authors.lastname: Burak
authors.forename: C R
authors.initials: CR
authors.lastname: Geard
authors.forename: T
authors.initials: T
authors.lastname: Azizova
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002869:Chromosome Aberrations; D019457:Chromosome Breakage / Q000235:genetics; D002877:Chromosomes, Human / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D018499:Linear Energy Transfer / Q000235:genetics*; D008214:Lymphocytes / Q000528:radiation effects*
chemical_list: D015415:Biomarkers