title: Cytogenetic effects of energetic ions with shielding.
abstract: In order to understand the effects of shielding on the induction of biological damages by charged particles, we conducted experiments with accelerated protons (250 MeV) and iron particles (1 GeV/u). Human lymphocytes in vitro were exposed to particle beams through polyethylene with various thickness, and chromosomal aberrations were determined using FISH technique. Dose response curves for chromosome aberrations were obtained and compared for various particle types. Experimental results indicated that for a given absorbed dose at the cell, the effectiveness of protons and iron particles in the induction of chromosomal aberrations was not significantly altered by polyethylene with thickness up to 30-cm and 15-cm respectively. Comparing with gamma rays, charged particles were very effective in producing complex chromosomal damages, which may be an important mechanism in alterating functions in non dividing tissues, such as nervous systems.
authors.affiliation: NASA Johnson Space Center, Radiation Biophysics Laboratory, Houston, TX 77058, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Yang
authors.forename: K A
authors.initials: KA
authors.lastname: George
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: D
authors.initials: D
authors.lastname: Miller
authors.forename: J
authors.initials: J
authors.lastname: Miller
mesh_terms: D002869:Chromosome Aberrations; D002889:Chromosomes, Human, Pair 2 / Q000528:radiation effects; D002894:Chromosomes, Human, Pair 4 / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D020450:Heavy Ions; D006801:Humans; D007501:Iron; D018499:Linear Energy Transfer; D008214:Lymphocytes / Q000166:cytology / Q000528:radiation effects*; D010315:Particle Accelerators; D011095:Polyethylenes; D011522:Protons; D011829:Radiation Dosage; D011835:Radiation Protection
chemical_list: D011095:Polyethylenes; D011522:Protons; D007501:Iron